Highly stereoselective samarium(II) iodide-mediated aldol reactions of acylaziridines with aldehydes

Ó 2005 The Chemical Society of Japan

Bull. Chem. Soc. Jpn., 78, 1309–1333 (2005) 1309

Highly Stereoselective Samarium(II) Iodide-Mediated Aldol

Reactions of Acylaziridines with Aldehydes

ꢀ;1;2

Yasuyuki Ogawa,¹Kiichi Kuroda,¹and Teruaki Mukaiyama

¹Center for Basic Research, The Kitasato Institute, 6-15-5 (TCI) Toshima, Kita-ku, Tokyo 114-0003

²Kitasato Institute for Life Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641

Received January 31, 2005; E-mail: mukaiyam@abeam.ocn.ne.jp

The samarium(II) iodide-mediated stereoselective aldol reactions of acylaziridines with aldehydes are described.

ꢀ-Amino–ꢀ⁰-hydroxy ketones were synthesized in high yields by the aldol reaction of aldehydes with samarium enolates

generated by aziridine-fragmentation of aziridinyl ketones with two moles of samarium(II) iodide. By the choice of an

appropriate nitrogen protecting group, depending on the substituent at C-3 position of aziridinyl ketone, anti,anti-ꢀ-ami-

no–ꢀ⁰-hydroxy ketones were diastereoselectively obtained among the four possible diastereomers. Further, enantiomeri-

cally pure anti,anti-ꢀ-amino–ꢀ⁰-hydroxy ketones were successfully obtained by this aldol reaction when chiral aziridinyl

ketones were used. In addition, ꢁ-amino–ꢀ⁰-hydroxy–ꢀ,ꢂ-unsaturated esters were also synthesized in high yields by the

aldol reaction of aldehydes with samarium enolates generated by aziridine-fragmentation and oleﬁn-migration of ꢂ,ꢁ-

aziridinyl–ꢃ,ꢀ-unsaturated esters using two moles of samarium(II) iodide. This aldol reaction proceeded with complete

ꢃ-regioselectivity and formed (E)-oleﬁn selectively. By introducing chiral oxazolidin-2-one auxiliary to ꢂ,ꢁ-aziridinyl–

ꢃ,ꢀ-unsaturated carbonyl system, this reaction was extended successfully to the asymmetric reaction and enantiomeri-

cally pure syn-ꢁ-amino–ꢀ⁰-hydroxy-ꢀ,ꢂ-unsaturated esters were obtained in high yields.

Samarium(II) iodide (SmI₂) is known as a powerful one-

electron reducing agent and a wide variety of functional

groups can be reduced under mild conditions.¹One of the most

widely employed processes using SmI₂is the reductive cleav-

age of ꢃ-hetero-substituted carbonyl compounds.²The reduc-

tion of substrates possessing small rings adjacent to the car-

bonyl group is known as a useful synthetic method. Oxiranyl

ketones³and esters,⁴aziridinyl ketones and esters,⁵and vinyl

oxiranes,⁶etc. are successfully reduced with SmI₂in the pres-

ence of a proton source such as methanol and the correspond-

ing ring-opening products are obtained (Scheme 1). It is

known that these reactions proceed through successive one-

electron transfer processes to generate samarium enolates I,

followed by protonation at ꢃ-carbon atom (Scheme 2,

I ! II). These intermediates, samarium enolates I, are consid-

ered as nucleophilic enolates, which react with electrophiles

such as aldehydes (I ! III). This consideration prompted us

to study SmI₂-mediated aldol reaction of oxiranyl ketones with

aldehydes; expectedly, the reaction aﬀorded 3-hydroxy-2-(1-

hydroxyalkyl)alkyl ketones (double-aldols) in high yields.⁷

This practical reaction was successfully applied to synthesis

of taxane skeleton.⁸Then, the use of aziridinyl ketones instead

of the above mentioned oxiranyl ketones was planned next in

order to ﬁnd its new possibility in synthetic chemistry. Thus

formed aldol adducts are considered to be 3-amino-2-(1-hy-

droxyalkyl)alkyl ketones (ꢀ-amino–ꢀ⁰-hydroxy ketones).

In recent years, synthesis of ꢀ-amino acids has attracted

considerable attention.⁹Among various substituted ꢀ-amino

acids, especially ꢀ⁰-hydroxy derivatives are actually constitut-

ed as an important class of molecules with interesting chemical

and biological properties, due to their similarity to serine and

other unusual amino acids. Therefore, ꢀ-amino–ꢀ⁰-hydroxy

ketones are considered as important analogues of ꢀ-amino–

ꢀ⁰-hydroxy acids and are expected to work as useful building

blocks for the synthesis of biologically important compounds;

O

OH

C H

O

SmI (2 eq.)

2

SmI₂

O

SmI₂

5

11

X

C H

5

THF / MeOH

X

11

81%

R₁

R₂

R₁

R₂

−90 °C

X = O, NR

Ts

SmI₂

O

NHTs

Ph

O

SmI (2 eq.)

2

N

O

XH

R₂

Ph

THF / MeOH

I₂Sm

R₁

SmI₂

O

XH

R₂

O

X

R₃CHO

82%

H₃O⁺

0 °C

R₁

HO

R₁

R₂

R₃

EtO C

2

SmI (2 eq.)

2

II

X = O; mono-aldol

-amino ketone

I

III

O

OH

C H

X = O; double-aldol

X = NR; -amino−

THF / EtOH

C H

5

11

5

11

'-hydroxy

β

X = NR;

−98 °C

84%

ketone

Scheme 1.

Scheme 2.

Published on the web July 1, 2005; DOI 10.1246/bcsj.78.1309

1310 Bull. Chem. Soc. Jpn., 78, No. 7 (2005)

SmI₂-Mediated Aldol Reactions of Acylaziridines

however, their syntheses have not yet been reported. In this pa-

per, we would like to describe a new and eﬃcient method for

stereoselective synthesis of ꢀ-amino–ꢀ⁰-hydroxy ketones by

the SmI₂-mediated aldol reaction of aziridinyl ketones with al-

dehydes.¹⁰A possible reaction mechanism is put forward that

accounts for conﬁgurations of the resulting aldol adducts.

Ha

O

NHTs

O

Ph

Hb

Ph

Me

triphosgene

O

Ph

HO

syn,anti-1d (B)

Me

pyridine

(92%)

Ts

N

Hc

Ph

O

2

Hc

Results and Discussion

O

Ts

O

NHTs

Me

Ha

Me

Stereoselective Synthesis of ꢀ-Amino–ꢀ⁰-Hydroxy Ke-

tones by the Samarium(II) Iodide-Mediated Aldol Reaction

of Aziridinyl Ketones with Aldehydes.¹⁰Aziridinyl ketones

were prepared from the corresponding ꢃ,ꢀ-unsaturated ke-

tones according to the literature procedures.^11,12In the ﬁrst

place, the SmI₂-mediated aldol reaction of trans-2-benzoyl-

3-methyl-1-tosylaziridine (1), an aryl aziridinyl ketone, with

several aldehydes was examined (Table 1). The reaction of 1

with benzaldehyde was carried out at ꢁ78 ^ꢂC in THF by add-

ing a THF solution of SmI₂. The corresponding ꢀ-amino–ꢀ⁰-

hydroxy ketone (1a) was obtained in a good yield (67/33 mix-

ture of syn,anti (B) and anti,anti (D) isomers) along with a

small amount of reduction product, ꢀ-N-tosylamino ketone

(Entry 1). The yields of the products were greatly inﬂuenced

by the substituents on the aromatic ring of the aldehydes (En-

tries 2 and 3). When 4-chlorobenzaldehyde having an electron-

withdrawing substituent on the aromatic ring was used, no

product was obtained because it was easily reduced by SmI₂

to promote competitive pinacol coupling. On the other hand,

the reaction of 1 with aliphatic aldehydes proceeded smoothly

to give the corresponding ꢀ-amino–ꢀ⁰-hydroxy ketones (1c–

1f) in excellent yields (Entries 4–7). The reaction proceeded

rapidly under nearly neutral conditions, and this is considered

as one of the important factors which contribute to the high

yielding of the products. All entries aﬀorded the syn,anti (B)

and anti,anti (D) isomers as major products among the four

possible diastereomers. These results are similar to those of

SmI₂-mediated formations of double-aldols by the reaction

of oxiranyl ketones with aldehydes.⁷

N

triphosgene

Ph

HO

Hb

O

pyridine

(70%)

Ph

O

Ph

anti,anti-1d (D)

3

JHa-Hb

JHb-Hc

: NOE

2

3

4.0 Hz

3.5 Hz

2.5 Hz

6.0 Hz

Scheme 3.

The relative conﬁgurations at newly created stereo-centers

of the ꢀ-amino–ꢀ⁰-hydroxy ketones were determined by

chemical transformation and NOE experiments (Scheme 3).

Namely, treatment of syn,anti-1d and anti,anti-1d with tri-

phosgene in pyridine aﬀorded the carbamates 2 and 3, which

were analyzed by NOE diﬀerence spectroscopy. The NOEs be-

tween Ha and Hb, Hb and methyl proton, and Ha and methyl

proton of 2 clearly indicated the syn,anti conﬁguration. Simi-

larly, the NOEs between Ha and Hb, Hb and Hc, and Ha

and Hc of 3 clearly indicated the anti,anti conﬁguration. The

relative conﬁgurations of other products were deduced by

comparison of their ¹H NMR and ¹³C NMR spectra with those

of syn,anti-1d and anti,anti-1d (Table 2).

Next, the SmI₂-mediated aldol reactions of various aziridinyl

ketones with various aldehydes were further examined

(Table 3). The reactions between aryl aziridinyl ketones and al-

dehydes in the presence of SmI₂also proceeded smoothly to af-

ford the corresponding ꢀ-amino–ꢀ⁰-hydroxy ketones (4a–8b)

in excellent yields (Entries 1–10). Such results indicated that

the substituents at C-3 position (R₂) play an important role in

the control of stereoselectivity. When the reactions with aziri-

dinyl ketones 1 and 4 having a primary alkyl substituent

(R₂¼ Me, n-Pr) were tried, mixtures of two diastereomers

(syn,anti isomer (B) and anti,anti isomer (D)) were aﬀorded

with poor selectivities. Comparison of these observed diaster-

eoselectivities revealed that they were improved when the bulk-

iness of the aldehyde increased (Table 1 and Table 3, Entries 1

and 2). On the other hand, it is noteworthy that the reactions af-

forded the corresponding products with high anti,anti diaster-

eoselectivities irrespective of the structures of aldehydes when

aziridinyl ketones 5 and 6 having a bulky substituent (R₂¼

i-Pr, t-Bu) were used (Entries 3–6). In the case of aziridinyl ke-

tone 7 having an aryl group, anti,anti isomer (D) was obtained

as a main product along with a small amount of an unidentiﬁed

syn,syn isomer (A) or anti,syn isomer (C) (Entries 7 and 8).

On the other hand, the reactions of unsubstituented aziridinyl

ketone 8 with aldehydes gave only anti isomers, as expected

(Entries 9 and 10). In addition, it is noted that alkyl aziridinyl

ketone 9 also reacted with aldehydes to give the corresponding

products (9a–9c) in high yields (Entries 11–13).

Table 1. The SmI₂-Mediated Aldol Reaction of Aziridinyl

Ketone (1) with Various Aldehydes

Ts

O

SmI (2.5 eq.) / THF

2

N

A + B + C + D

1a−1f

Ph

Me

RCHO (1.1 eq.)

1

−78 °C

O

NHTs

Me

O

NHTs

Me

O

NHTs

Me

O

NHTs

Ph

HO

Ph

HO

Ph

HO

syn,anti (B)

Me

R

HO

R

syn,syn (A)

anti,syn (C)

anti,anti (D)

Aldehyde

Entry

Product Yield/%^a)

(A/B/C/D)^b)

R

1

2

3

4

5

6

7

Ph

1a

1b

80

85

(0/67/0/33)

(0/<5/0/>95)

4-MeOC₆H₄

4-ClC₆H₄

Et

Ph(CH₂)₂

i-Pr

c-Hex

ND^c)

95

1c

1d

1e

1f

(0/34/0/66)

(0/40/0/60)

(0/28/0/72)

91

98

95

a) Isolated yield. b) The ratio was determined by ¹H NMR.

c) Unidentiﬁed products were formed.

Then, in order to establish the generality of this reaction, we

examined the reaction of aziridinyl ketones having other nitro-

Y. Ogawa et al.

Bull. Chem. Soc. Jpn., 78, No. 7 (2005) 1311

Table 2. Chemical Shifts (H_a, H_b, H_c, H_d, H_e, C_carbonyl) and Coupling Constants (J_ab, J_bc, J_ad, J_ce) for ꢀ-Amino–ꢀ⁰-Hydroxy

Ketones

Compound

ꢁ (H_a) ꢁ (H_b) ꢁ (H_c) ꢁ (H_d) ꢁ (H_e) ꢁ (C_carbonyl

)

J_ab/Hz J_bc/Hz J_ad/Hz J_ce/Hz

Ha

1a

1c

1d

1e

1f

3.80

3.95

3.94

3.91

4.02

3.54

3.51

3.66

3.64

5.32

4.01

4.16

3.66

3.72

5.22

5.45

5.47

5.63

5.72

3.80

3.48

3.67

3.66

3.68

202.1

202.4

202.9

202.7

6.9

6.3

6.6

6.8

7.0

4.3

2.7

2.5

8.4

8.6

8.4

8.6

ND^a)

9.1

O

NHdTs

R₂

R₁

H^b

R₃

Hc

9.2

b)

HeO

—

syn,anti (B)

2.2

8.0

Ha

1a

1c

1d

1e

1f

3.61

3.83

3.87

3.79

3.70

3.94

3.64

3.73

3.82

5.20

3.88

4.05

3.79

3.73

5.74

5.67

5.57

5.73

5.72

2.80

2.69

2.89

2.80

2.75

204.2

205.0

204.8

205.5

4.3

5.8

5.6

5.5

5.9

7.4

5.8

5.6

5.5

5.3

9.0

9.2

8.4

8.6

ND^a)

7.1

8.1

7.2

O

NHdTs

R₂

R₁

Hb

Hc

R₃

HeO

anti,anti (D)

7.7

a) Not detected. b) Signals overlapped.

Table 3. The SmI₂-Mediated Aldol Reaction of Various Aziridinyl Ketones with Various Aldehydes

Ts

SmI₂(2.5 eq.) / THF

O

N

A + B + C + D

4a−9c

R₃CHO (1.1 eq.)

R₁

R₂

4−9

−78 °C

O

NHTs

R₂

R₃

anti,syn (C)

O

NHTs

R₂

O

NHTs

R₂

O

NHTs

R₁

R₂

R₁

HO

syn,anti (B)

HO R₃

HO

R₃

syn,syn (A)

anti,anti (D)

Aziridinyl ketone

Aldehyde

Entry

Product

Yield/%^a)

(B/D/others)^b)

R₁

R₂

R₃

1

2

3

4

5

6

7

8

9

10

11

12

13

4

5

6

7

8

9

Ph

Me

n-Pr

i-Pr

t-Bu

Ph

H

Ph

Ph(CH₂)₂

i-Pr

Ph(CH₂)₂

i-Pr

Ph(CH₂)₂

i-Pr

Ph(CH₂)₂

i-Pr

Ph(CH₂)₂

i-Pr

Ph

Ph(CH₂)₂

i-Pr

4a

4b

5a

5b

6a

6b

7a

7b

8a

8b

9a

9b

9c

88

92

98

99

96

99

96

97

86

83

73

88

99

(29/71/0)

(14/86/0)

(<5/>95/0)

(28/55/7)

(13/71/6)

c)

—

c)

(70/30/0)

(38/62/0)

(29/71/0)

Ph

1

a) Isolated yield. b) The ratio was determined by H NMR. c) The anti isomer was only obtained.

gen protecting groups with 3-phenylpropanal (Table 4). All en-

tries aﬀorded the corresponding ꢀ-amino–ꢀ⁰-hydroxy ketones

(10a–16a) in high yields, indicating that this reaction is toler-

ant of a variety of nitrogen-protecting groups. It was found that

the stereoselectivity of this reaction was inﬂuenced by the ni-

trogen-protecting groups. When acetyl (Ac), t-butoxycarbonyl

(Boc), benzyloxycarbonyl (Cbz), and 9-ﬂuorenylmethoxycar-

bonyl (Fmoc) were used as nitrogen-protecting groups, the

high diastereoselectivities were observed (Entries 3, 5–7). It

is noteworthy that the reaction proceeded smoothly in a high

yield with excellent diastereoselectivity to give only anti,anti

isomer (D) in the case when Fmoc was used as a protecting

group (Entry 7).

ketones with various aldehydes were examined; the products

were obtained in good to high yields (Table 5). It was also

found that the substituents at C-3 position (R₂) play an impor-

tant role in control of the stereoselectivity. Contrary to the case

of using Ts as a protecting group, the reactions with aziridinyl

ketones 16 and 17 having a primary alkyl substituent

(R₂¼ Me, n-Pr) aﬀorded the anti,anti isomers (D) with high

diastereoselectivities irrespective of the structures of aldehydes

(Entries 1–5), and the reactions with aziridinyl ketones having

a bulky substituent (R₂¼ i-Pr) gave mixtures of two diaster-

eomers with poor selectivities in lower yields (Entries 6 and

7). In addition, the reactions with aziridinyl ketone having

an aryl substituent aﬀorded mixtures of two diastereomers

with moderate selectivity (Entries 8 and 9). These results are

in contrast to those of the reactions with tosylaziridinyl ke-

tones.

Since it was found that Fmoc was the most appropriate ni-

trogen-protecting group in the reaction with 3-phenylpropanal,

the SmI₂-mediated aldol reactions of various Fmoc-aziridinyl

1312 Bull. Chem. Soc. Jpn., 78, No. 7 (2005)

SmI₂-Mediated Aldol Reactions of Acylaziridines

As described above, it was found that anti,anti-ꢀ-amino–ꢀ⁰-

hydroxy ketone was selectively obtained by choosing the ap-

propriate nitrogen-protecting group depending on the substitu-

ent at the C-3 position of aziridinyl ketone (Table 6).

Next, the aldol reaction of a chiral aziridinyl ketone with al-

dehyde was tried in the presence of SmI₂. It was considered

that this reaction becomes synthetically more useful when this

aldol reaction is applied to an enantiomeric case. The chiral N–

H aziridinyl ketone 22 (96% ee by HPLC analysis) was pre-

pared according to the literature procedure.¹³Then, aziridine

22 was treated with tosyl chloride (TsCl) and (4-dimethylami-

no)pyridine (DMAP) to aﬀord chiral N-tosylaziridinyl ketone

5 (Scheme 4).

Treatment of the mixture of the optically active ketone

(2S,3R)-5 and 3-phenylpropanal in THF with THF solution

0

ꢂ

of SmI₂at ꢁ78 C gave the corresponding ꢀ-amino–ꢀ -hy-

droxy ketone 5a in high yield with high diastereoselectivity

(syn,anti/anti,anti = 3/97) (Scheme 5). It was noteworthy

that the excellent optical purity of the ꢀ-amino–ꢀ⁰-hydroxy

ketone 5a produced was kept throughout the present protocol

(96% ee (anti,anti isomer) by HPLC analysis). In the case

of the reaction with isobutyraldehyde, the product was also

obtained in a high yield with a high diastereoselectivity (syn,

anti/anti,anti = 3/97, 96% ee).

One possible reaction mechanism is shown in Scheme 6.

The reaction is assumed to proceed via successive one-electron

transfer from SmI₂to the ketone, followed by opening of the

aziridine ring to aﬀord the corresponding ꢀ-amino samarium

enolate.⁵The formation of a chelated structure is considered

to be crucial for the initial electron transfer^4a,14because simple

ketones are not reduced by SmI₂in THF at ꢁ78 ^ꢂC. Addition-

ally, this consideration can explain the observation that aziri-

dinyl ketones are more quickly reduced compared with coex-

isting aldehydes. Condensation with an aldehyde then pro-

duced the desired ꢀ-amino–ꢀ⁰-hydroxy ketone. The stereose-

lectivity attained in the aldol reaction can be explained

reasonably by considering the six-membered boat-like transi-

Table 4. The SmI₂-Mediated Aldol Reaction of Aziridinyl

Ketones Having Various Protecting Groups with 3-Phen-

ylpropanal

R

O

SmI₂(2.5 eq.) / THF

N

A + B + C + D

10a−16a

Ph

Me

Ph(CH)₂CHO (1.1 eq.)

10−16

−78 °C

O

NHR

Me

O

NHR

Me

O

NHR

Me

O

NHR

Me

Ph

HO

anti,syn (C)

Ph

HO

syn,syn (A)

Ph

Ph HO

Ph

HO

Ph

syn,anti (B)

anti,anti (D)

Table 6. The SmI₂-Mediated Diastereoselective Aldol

Reaction

Aziridine

R

Entry

Product Yield/%^a)

(A/B/C/D)^b)

O

NHR

O

NHR

R

N

O

1

2

3

4

5

6

7

10

Ms

Mts^c)

Ac

10a

11a

12a

13a

14a

15a

16a

96

85

82

93

88

94

(0/29/0/71)

(0/42/0/58)

(0/10/0/90)

(0/34/0/66)

(0/12/0/88)

(0/<5/0/>95)

SmI (2.5 eq.) / THF

2

R

2

R

1

R

1

2

+

R

2

11

12

13

14

15

16

1

R CHO (1.1 eq.)

3

HO

syn,anti

anti,anti - selective

R

HO

R

3

−78 °C

anti,anti

Bz

Boc

Cbz

Fmoc

R₂

alkyl (primary)

alkyl (secondary, tertiary)

aryl

R

syn,anti/anti,anti

Fmoc

Ts

Fmoc

1/5–1/>20

1/>20

1/2–1/9

a) Isolated yield. b) The ratio was determined by ¹H NMR.

c) Mts:2,4,6-trimethylbenzenesulfonyl.

Table 5. The SmI₂-Mediated Aldol Reaction of Fmoc-Aziridinyl Ketones with Various Aldehydes

Fmoc

SmI (2.5 eq.) / THF

O

2

N

A + B + C + D

16a−19b

R CHO (1.1 eq.)

3

R

2

1

16−19

−78 °C

O

NHFmoc

O

NHFmoc

O

NHFmoc

O

NHFmoc

R

2

R

2

R

2

1

2

1

HO

R

HO

R

3

HO

R

3

HO

R

3

syn,syn (A)

syn,anti (B)

anti,syn (C)

anti,anti (D)

Azyridinyl ketone

R₁

Aldehyde

R₃

Entry

Product

Yield/%^a)

(A/B/C/D)^b)

R₂

1^c)

2

3

4

5

6

7

8

16

Ph

Me

n-Pr

i-Pr

Ph

Ph(CH₂)₂

Ph

i-Pr

Ph(CH₂)₂

i-Pr

Ph(CH₂)₂

i-Pr

Ph(CH₂)₂

i-Pr

16a

16b

16c

17a

17b

18a

18b

19a

19b

94

67

92

93

96

84

72

81

76

(0/<5/0/>95)

(0/18/0/82)

(0/<5/0/>95)

(0/63/0/37)

(0/42/0/58)

(0/32/0/68)

(0/9/0/91)

17

18

19

9

Ph

1

a) Isolated yield. b) The ratio was determined by H NMR. c) The result of Table 4, Entry 7.

Y. Ogawa et al.

Bull. Chem. Soc. Jpn., 78, No. 7 (2005) 1313

P

N

SmI₂

R₂

OCHPh

2

P

N

Ph CHONH

2

O

HN

SmI₂

O

Ph

2

O

SmI₂

Sc[(R)-BNP]

3

R₁

Ph

R₁

R₂

toluene

-aziridinyl−

unsaturated ester

-

γ,δ

α,β

(S)-21

20

75%, 96% ee

H

O

P

SmI₂

R₂

N

H₃O⁺

NH

O

N

O

TsCl, DMAP

CH Cl

t-BuONa

Ph

R₁

R₂

R₁

2

THF

(2S, 3R)-22

R₃CHO

P

95%, 96% ee

O

Ts

O

R₁

R₂

N

R₃

OH

Ph

-amino− ′-hydroxy− -

β,γ

δ

β

(2S, 3R)-5

unsaturated ester

62%, 96% ee

Scheme 7.

Scheme 4.

Stereoselective Synthesis of ꢁ-Amino–ꢀ⁰-Hydroxy–ꢀ,ꢂ-

Unsaturated Esters by the Samarium(II) Iodide-Mediated

Aldol Reaction of ꢂ,ꢁ-Aziridinyl–ꢃ,ꢀ-Unsaturated Esters

with Aldehydes.¹⁶Next, in order to extend the generality

of this SmI₂-mediated aldol reaction, the uses of ꢂ,ꢁ-aziri-

dinyl–ꢃ,ꢀ-unsaturated esters instead of the above-mentioned

aziridinyl ketones were studied. Thus formed aldol adducts

were considered to be ꢁ-amino–ꢀ⁰-hydroxy–ꢀ,ꢂ-unsaturated

esters (Scheme 7).

The replacement of an amide bond in bioactive peptides

with a trans-double bond has long been a topic of interests

in biological, theoretical, and synthetic areas.¹⁷ꢁ-Amino–ꢀ⁰-

hydroxy–ꢀ,ꢂ-unsaturated esters¹⁸have been considered as im-

portant analogues of dipeptide and are expected to be used for

synthetic building blocks of various biologically important

polypeptides. Now, a new and eﬃcient method for the stereo-

selective synthesis of ꢁ-amino–ꢀ⁰-hydroxy–ꢀ,ꢂ-unsaturated

esters has been reported.¹⁶

The ꢂ,ꢁ-aziridinyl–ꢃ,ꢀ-unsaturated esters were prepared

according to the literature procedure.¹⁹In the ﬁrst place,

SmI₂-mediated aldol reaction of methyl (2E)-3-[(2R)-1-tosyl-

aziridin-2-yl]acrylate (23)¹⁹with several aldehydes was exam-

ined (Table 7). The reaction of 23 with benzaldehyde was car-

ried out at ꢁ78 ^ꢂC in THF by adding a THF solution of SmI₂;

the corresponding ꢁ-amino–ꢀ⁰-hydroxy–ꢀ,ꢂ-unsaturated ester

(23a) (27/73 mixture of syn and anti isomers) was obtained

in a good yield, along with a small amount of ꢁ-N-tosylami-

no-ꢀ,ꢂ-unsaturated methyl ester (Entry 1). The yield of 23a

slightly decreased because the reduction of benzaldehyde took

place competitively. Contrary to the reaction with aziridinyl

ketones, the reaction with ꢂ,ꢁ-aziridinyl–ꢃ,ꢀ-unsaturated es-

ters aﬀorded the corresponding products in good yields, irre-

spective of the aromatic aldehydes having an electron-with-

drawing group or an electron-donating group on the aromatic

ring (Entries 2 and 3). This result was explained by the diﬀer-

ence between reduction rates of ꢂ,ꢁ-aziridinyl–ꢃ,ꢀ-unsaturat-

ed esters and aziridinyl ketones. Further, the reaction of 23

with aliphatic aldehydes proceeded very rapidly to give the

corresponding ꢁ-amino–ꢀ⁰-hydroxy–ꢀ,ꢂ-unsaturated esters

(23d–23h) in excellent yields (Entries 4–8). It is noted that

no oleﬁnic isomers and dienes were detected in this reaction.

It is quite clear that nearly neutral conditions are kept during

the reaction; therefore the isomerization to a more stable ole-

Ts

O

NHTs

Ph

N

SmI₂(2.5 eq.) / THF

Ph

HO

Ph

Ph(CH₂)₂CHO (1.1 eq.)

−78 °C

(2S, 3R)-5

96% ee

83%, 94% de

(2S, 3R, 2'S)-5a

96% ee

O

NHTs

SmI₂(2.5 eq.) / THF

Ph

HO

(2S, 3R)-5

i-PrCHO (1.1 eq.)

−78 °C

96% ee

i-Pr

98%, 94% de

(2S, 3R, 2'S)-5b

96% ee

Scheme 5.

SmI₂

Ts

O

SmI₂

Ts

O

Ts

N

R₁

R₂

R₁

R₂

I

Sm

SmI₂

Ts

I₂Sm

Ts

H

R₃CHO

SmI₂

O

N

R₁

H

R₂

O

NHTs

R₂

O

R₁

HO

R₃

favored

H

R₃

I

Sm

anti,anti

major

O

NTs

H

R₁

R₂

O

NHTs

R₂

O

R₁

HO

R₃

disfavored

R₃

H

syn,anti

minor

Scheme 6. The possible reaction mechanism.

tion state, in which the samarium enolate possessed (Z)-conﬁg-

uration by chelation of samarium between the amino group

and the carbonyl, and the diastereofacial selectivity was deter-

mined by R₂group.¹⁵Thus, this aldol reaction aﬀorded the

anti,anti-ꢀ-amino–ꢀ⁰-hydroxy ketone as a main product.

1314 Bull. Chem. Soc. Jpn., 78, No. 7 (2005)

SmI₂-Mediated Aldol Reactions of Acylaziridines

Table 7. The SmI₂-Mediated Aldol Reaction of ꢂ,ꢁ-Aziri-

dinyl–ꢃ,ꢀ-Unsaturated Ester (1) with Various Aldehydes

Table 8. Chemical Shifts (H_a, H_b) and Coupling Constants

(J_ab) for ꢁ-Amino–ꢀ⁰-Hydroxy–ꢀ,ꢂ-Unsaturated Esters

NHTs

O

NHTs

O

Ts

N

Compound

ꢁ (H_a)

ꢁ (H_b)

J_ab/Hz

O

SmI₂(2.5 eq.) / THF

OMe

OH

OMe

+

23a

23d

23e

23f

23g

23h

3.26

3.02

3.01

3.18

3.21

3.24

5.02

3.80

3.89

3.63

3.61

3.62

5.4

4.3

4.6

4.9

OMe

RCHO (1.1 eq.)

R

OH

23

NHTs

O

−78 °C

syn

anti

Ha

23a−23h

OMe

Hb

OH

syn

R

Aldehyde

Entry

Product

Yield/%^a)

(syn/anti)^b)

R

1

2

3

4

5

6

7

8

Ph

23a

23b

23c

23d

23e

23f

63

95

75

92

96

86

94

97

(27/73)

(49/51)

(39/61)

(55/45)

(51/49)

(56/44)

(54/46)

(57/43)

4-MeOC₆H₄

4-ClC₆H₄

Et

Ph(CH₂)₂

i-Pr

c-Hex

23a

23d

23e

23f

23g

23h

3.34

3.07

3.18

3.23

3.26

4.84

3.65

3.74

3.50

3.47

3.52

8.1

7.6

7.3

7.8

0

NHTs

O

Ha

OMe

Hb

OH

anti

R

23g

23h

t-Bu

1

a) Isolated yield. b) The ratio was determined by H NMR.

Table 9. The SmI₂-Mediated Aldol Reaction of ꢂ,ꢁ-Aziri-

dinyl–ꢃ,ꢀ-Unsaturated Ester (23) with Various Ketones

R

NHTs

O

Ts

N

O

SmI₂(2.5 eq.) / THF

H

NHTs

O

OMe

1) DIBAL

2) CSA

OMe

R₁R₂CO (1.1 eq.)

H

OMe

OH

syn-23e

R₁

OH

23

O

−78 °C

R₂

23i−23l

Ha

O

R

Me

R

2,2-dimethoxypropane

H

(45% in 2 steps)

Hb

Me

Ketone

R₁

Entry

Product Yield/%^a)(Diastereomeric ratio)

24

R₂

Ha

1

2

3

4

Ph(CH₂)₂Me

23i

Me 23j

98

94

87

95

(56/44)^b)

NHTs

O

H

1) DIBAL

R

O

Me

Et

—

OMe

OH

O

R

H

Me

2) CSA

2,2-dimethoxypropane

(42% in 2 steps)

Et

23k

23l

H

R

–(CH₂)₅–

Hb

Me

anti-23e

25

a) Isolated yield. b) The stereochemistries were not deter-

mined.

24

25

9.5 Hz

: NOE

J(Ha-Hb)

2.4 Hz

NHTs

O

Ts

N

Scheme 8.

O

SmI₂(2.5 eq.) / THF

OMe

Me₂CO (1.1 eq.)

ﬁnic isomer or ꢀ-elimination was prevented. A characteristic

point of this aldol reaction is that it proceeded with complete

ꢃ-regioselectivity and formed (E)-oleﬁn selectively, whereas

no diastereoselectivity was observed (syn/anti = 27/73–

57/43).

Me

OH

−78 °C

26

Me

26a (96%, dr = 1:1)

Scheme 9.

The (E)-oleﬁn stereochemistry of 23e was assigned based

on the relevant vicinal coupling constant (J ¼ 15:7 Hz). The

relative conﬁguration at newly created stereo-centers of 23e

was determined by chemical transformation and measurement

of the coupling constants of their acetonide derivatives

(Scheme 8). Namely, reduction of syn-23e and anti-23e with

diisobutylaluminium hydride (DIBAL) aﬀorded the diols,

which converted to the corresponding acetonide derivatives

24 and 25. The observation of an equatorial–axial coupling

constant (J ¼ 2:4 Hz) between Ha and Hb in the ¹H NMR data

of 24 indicated that 24 has syn conﬁguration. On the other

hand, the observation of a diaxial coupling constant (J ¼ 9:5

Next, the possible applications of this aldol reaction to ke-

tones were examined. Then, the reaction also proceeded

smoothly to aﬀord the corresponding ꢁ-amino–ꢀ⁰-hydroxy–

ꢀ,ꢂ-unsaturated esters (23i–23l) in high yields (Table 9).

The product 26a was obtained in a high yield by the reaction

of 26 with acetone, however, almost no stereoselectivity was

observed (Scheme 9). It seems that the distal substituent on

the ꢁ-carbon has no stereodirecting eﬀect concerning the in-

coming electrophile.

Next, the aldol reaction was examined by using other aziri-

dinyl unsaturated esters in order to improve the diastereoselec-

tivity (Table 10). In this reaction, the bulkiness of the R group

did not inﬂuence on the reactivity, and the products were ob-

tained in high yields. Comparison of the observed diastereo-

selectivities revealed that some bulkiness of the R group would

be crucial to achieve good stereoselectivity. In particularly,

high syn diastereoselectivity (syn/anti = 90/10) was observed

1

Hz) between Ha and Hb in the H NMR data of 25 indicated

that 25 has anti conﬁguration. The relative conﬁgurations of

1

other products were deduced by comparison of their H NMR

and ¹³C NMR spectra with those of syn-23e and anti-23e

(Table 8).

Y. Ogawa et al.

Bull. Chem. Soc. Jpn., 78, No. 7 (2005) 1315

Table 10. The SmI₂-Mediated Aldol Reaction of Various

Unsaturated Aziridines with 3-Phenylpropanal

Table 11. The SmI₂-Mediated Aldol Reaction of Various

Unsaturated Aziridines with 3-Phenylpropanal

NHTs

O

NHTs

O

NHTs

O

NHTs

O

Ts

N

Ts

N

O

SmI₂(2.5 eq.) / THF

R

+

R

Ph(CH₂)₂CHO (1.1 eq.)

Ph

OH

Ph

OH

Ph

OH

Ph

OH

23−30

31−34

−78 °C

syn

anti

syn

anti

23e−30a

31a−34a

Aziridine

R

Aziridne

Entry

Product Yield/%^a)(syn/anti)^b)

Entry

Product Yield/%^a)(syn/anti)^b)

R

1

2

3

4

5

23

27

28

29

OMe

OBn

O-t-Bu

OPh

23e

27a

28a

29a

30a

96

99

98

95

97

(51/49)

(70/30)

(71/29)

(73/27)

(90/10)

1

2

3

4

31

32

33

Ph

NEt₂

pyrrolidine

31a

32a

33a

34a

61

83

82

81

(58/42)

(60/40)

(47/53)

34 2-oxazolidinone

(>95/<5)

30 O-2,6-diMe-Ph

1

a) Isolated yield. b) The ratio was determined by H NMR.

1

a) Isolated yield. b) The ratio was determined by H NMR.

Table 12. The Asymmetric SmI₂-Mediated Aldol Reaction

Ts

N

O

NHTs

R

O

SmI (2.5 eq.) / THF

2

R

N

O

R

N

O

1

R CHO (1.1 eq.)

2

OH

2

35, 36 Bn

Bn

−78 °C

35a−36b

Aziridine

Entry

Product

Yield %^a)

(syn anti)^b)

R₁

R₂

Ph(CH₂)₂

Et

1

2

3

4

5

6

7

8

35

H

35a

35b

35c

35d

93

85

(>95 <5)

i-Pr

81

c-Hex

t-Bu

77

ND^c)

ND^d)

86

Ph

(>95 <5)

36 Me

Ph(CH₂)₂

36a

36b

Me

i-Pr

76

a) Isolated yield. b) The ratio was determined by ¹HNMR. c) 37

was obtained in 85% yield. d) 37 was obtained in 82% yield.

O

NHTs

O

N

O

37

Bn

when 2,6-dimethylphenyl ester 30 was used (Entry 5).

Then, the aldol reaction was examined by using other unsat-

urated aziridines (ketone, amide, and imide) in order to estab-

lish the generality of this reaction (Table 11). Reactions be-

tween other unsaturated aziridines and 3-phenylpropanal also

proceeded smoothly and aﬀorded the corresponding ꢁ-ami-

no–ꢀ⁰-hydroxy–ꢀ,ꢂ-unsaturated carbonyl compounds (31a–

34a) in high yields. It is noted that an excellent syn diastereo-

selectivity was observed (syn/anti = >95/<5) when unsatu-

rated imide 34 was used (Entry 4).

Prompted by this result, we applied the aldol reaction to the

asymmetric one²⁰by introducing a chiral 2-oxazolidinone aux-

iliary²¹to the unsaturated aziridine with the expectation that it

would control the stereochemistry. In the ﬁrst place, the reac-

tion of (4R)-4-benzyl-3-[(2E)-3-((2R)-1-tosylaziridin-2-yl)-

acryloyl]oxazolidin-2-one (35) with 3-phenylpropanal was ex-

amined (Table 12, Entry 1). This asymmetric aldol reaction

proceeded smoothly and aﬀorded the corresponding product

35a in high yield with excellent syn diastereoselectivity

(syn/anti = >95/<5) and high diastereofacial selectivity

(>95/<5 for syn-isomer). Further, the corresponding products

(35b–35d) were also obtained in high yields with excellent dia-

stereoselectivities (syn/anti = >95/<5) and high diastereo-

facial selectivities (>95/<5 for syn-isomers) when other alde-

hydes were used (Entries 2–4). In this reaction, the major iso-

mers were formed with >95% diastereoselection, as judged by

1

the analysis of the H NMR measurements. With bulky alde-

hyde, however, such as pivalaldehyde, no aldol adduct was ob-

tained and the reduction product 37 resulted (Entry 5). In the

case of using benzaldehyde, no aldol adduct was obtained be-

cause one-electron reduction of benzaldehyde preferentially

causes its pinacol coupling (Entry 6). As described above,

the 2-oxazolidinone auxiliary exhibited excellent ability for

stereocontrol in the asymmetric SmI₂-mediated aldol reaction.

Next, the reaction of (4R)-4-benzyl-3-[(2E)-3-((2R,3S)-

3-methyl-1-tosylaziridin-2-yl)acryloyl]oxazolidin-2-one (36)

(Table 12, Entries 7, 8) and (4S)-4-benzyl-3-[(2E)-3-((2R,3S)-

3-methyl-1-tosylaziridin-2-yl)acryloyl]oxazolidin-2-one (38)

1316 Bull. Chem. Soc. Jpn., 78, No. 7 (2005)

SmI₂-Mediated Aldol Reactions of Acylaziridines

Table 13. The Asymmetric SmI₂-Mediated Aldol Reaction

SmI

2

SmI

2

Ts

N

Ts

N

O

TsN

O

Ts

O

NHTs

O

SmI

2

N

SmI (2.5 eq.) / THF

2

N

O

N

O

N

O

Me

N

O

Me

N

O

RCHO (1.1 eq.)

Bn

R

OH

38 Bn

Bn

−78 °C

38a, 38b

O

Entry

R

Product

Yield/%^a)

(syn/anti)^b)

O

Bn

O

NHTs

O

N

H

1

2

Ph(CH₂)₂

i-Pr

38a

38b

84

75

(>95/<5)

RCHO

N

O

I Sm

2

O

R

H

R

OH

O

Bn

1

a) Isolated yield. b) The ratio was determined by H NMR.

R

favored

1

NHTs

O

NHTs

O

NaOMe / MeOH

(85%)

OMe

N

O

Bn

O

N

O

NHTs

O

H

Ph

OH

(−)-syn-23e

= −27 (c 0.26, CHCl )

Ph

OH

SmI

2

N

O

R

Bn

H

syn-35a

O

R

OH

21

Bn

[α]

D

3

R

1

disfavored

Scheme 10.

Scheme 11. The assumed reaction mechanism.

NHTs

O

NHTs

O

(+)-MTPACl

DMAP

NHTs

O

NHTs

O

OMe

LiOH, H O

2

OH

pyridine

(57%)

O

N

Ph

OH

Ph

O(+)-MTPA

dioxane

0 °C

(80%)

(−)-syn-23e

39

40

Ph

OH

Bn

41

syn-35a

NHTs

O

23

(−)-MTPACl

DMAP

[α]

= −23 (c 0.40, CHCl )

D

3

OMe

pyridine

(78%)

Ph

O(−)-MTPA

NHTs

LiBH / THF

4

OH

syn-35a

EtOH

Ph

0 °C

∆δ (ppm) = δ [(−)-MTPA] - [(+)-MTPA]

42

= −7.9 (c 0.15, CHCl )

(74%)

23

[α]

D

3

OR

+0.135

-0.046

-0.020

Scheme 12.

-0.014

(R)

Ph

NHTs

+0.053

+0.078

-0.041

cessive one-electron transfer from SmI₂to cause both frag-

mentation of an aziridine ring and migration of a double bond.

Then, the samarium imide enolate^6,18,23was formed which in

turn nucleophilically attacks the aldehyde. The samarium

would play an important role in the transition state of the reac-

tion for inducing a high diastereoselectivity. Namely, the ster-

eoselectivity of the reaction is explained by the chelated six-

membered transition state model in which both the aldehyde

and the oxazolidinone carbonyl are coordinated to samari-

um^20,24and the diastereofacial selectivity was produced by

the steric eﬀect of benzyl group of oxazolidinone.

Finally, the transformation of these aldol adducts to carbox-

ylic acid and alcohol was tried. As shown in Scheme 12, syn-

35a was converted to carboxylic acid 41 in 80% yield on treat-

ment with LiOH and H₂O₂, while alcohol 42 was given in 74%

yield on treatment with LiBH₄.²⁵In these reactions, no detect-

able epimerization nor double bond conjugation was observed.

CO₂Me

(40 − 39)

Fig. 1. Application of the modiﬁed Mosher method.

(Table 13) with aldehydes was further tried. The products

were obtained in high yields with high diastereoselectivities

(syn/anti = >95/<5) and high diastereofacial selectivities

(>95/<5 for syn-isomers). Similar to the case of the reaction

with methyl ester 26 (Scheme 9), it was considered that the

distal substituent on the ꢁ-carbon has no stereodirecting eﬀect

with respect to the incoming aldehyde.

The relative stereochemistry of syn-35a was assigned by

converting to its structurally-deﬁned methyl ester (ꢁ)-syn-

23e by methanolysis (Scheme 10). And the absolute conﬁgura-

tion of (ꢁ)-syn-23e was determined by the modiﬁed Mosher

method.²²Namely, (ꢁ)-syn-23e was treated with (þ)- and

(ꢁ)-ꢃ-methoxy–ꢃ-triﬂuoromethylphenylacetyl (MTPA) chlo-

ride to give the (þ)- and (ꢁ)-MTPA esters (39 and 40) and

Conclusion

1

comparison of the H NMR data of 39 and 40 indicated that

The samarium(II) iodide-mediated aldol reactions of acyl-

aziridines with aldehydes were developed. ꢀ-Amino–ꢀ⁰-

hydroxy ketones were synthesized in high yields by the aldol

reaction of aldehydes with samarium enolates generated by

aziridine-fragmentation of aziridinyl ketones with two moles

of samarium(II) iodide. By choice of appropriate nitrogen-pro-

the absolute conﬁguration of ꢀ⁰-position of the carbonyl group

is (R)-conﬁguration (Fig. 1).

A reaction mechanism that can rationalize these observa-

tions is shown in Scheme 11. The ﬁrst step of this reaction in-

volves reduction of the aziridinyl unsaturated imide via suc-

Y. Ogawa et al.

Bull. Chem. Soc. Jpn., 78, No. 7 (2005) 1317

Typical Procedure for Samarium(II) Iodide-Mediated Aldol

Reaction of Aziridinyl Ketone with Aldehyde. (Table 1, Entry

5). To a mixture of aziridinyl ketone 1 (51.5 mg, 0.162 mmol)

and 3-phenylpropanal (23.9 mg, 0.178 mmol) in THF (4 mL) at

ꢁ78 ^ꢂC under an argon atmosphere was added a solution of SmI₂

in THF (0.1 M, 4.05 mL, 0.405 mmol). After the reaction mixture

was stirred for 1 h at ꢁ78 ^ꢂC, the reaction mixture was quenched

with saturated aqueous ammonium chloride and was diluted with

ethyl acetate. It was extracted with ethyl acetate, and the organic

layer was washed with brine and dried over anhydrous sodium sul-

fate. After evaporation of the solvent under reduced pressure, the

crude product was puriﬁed by thin-layer chromatography to aﬀord

syn,anti-1d (26.6 mg, 36%) and anti,anti-1d (39.8 mg, 54%), re-

spectively.

tecting groups of aziridinyl ketones, depending on the substitu-

ent at C-3 position of aziridinyl ketone, anti,anti-ꢀ-amino–ꢀ⁰-

hydroxy ketones were diastereoselectively obtained among the

four possible diastereomers. Furthermore, enantiomerically

pure anti,anti-ꢀ-amino–ꢀ⁰-hydroxy ketones were successfully

obtained by this aldol reaction with chiral aziridinyl ketones.

ꢁ-Amino–ꢀ⁰-hydroxy–ꢀ,ꢂ-unsaturated esters were also syn-

thesized in high yields by the aldol reaction of aldehydes with

samarium enolates generated by aziridine-fragmentation and

oleﬁn-migration of ꢂ,ꢁ-aziridinyl–ꢃ,ꢀ-unsaturated esters

using two moles of samarium(II) iodide. This aldol reaction

proceeded with complete ꢃ-regioselectivity and selectively

formed (E)-oleﬁn. By introducing chiral 2-oxazolidinone aux-

iliary to ꢂ,ꢁ-aziridinyl–ꢃ,ꢀ-unsaturated esters, we applied this

reaction successfully to the asymmetric reaction; enantiomeri-

cally pure syn-ꢁ-amino–ꢀ⁰-hydroxy–ꢀ,ꢂ-unsaturated esters

were obtained in high yields.

syn,anti-1a: Colorless oil. IR (neat) 3491, 3265, 1666, 1328,

1160 cm^ꢁ^{1 1}H NMR (270 MHz, CDCl₃) ꢁ 7.68–7.59 (m, 4H),

.

7.44 (t, J ¼ 8:1 Hz, 1H), 7.27–7.11 (m, 9H), 5.32 (d, J ¼ 4:3

Hz, 1H), 5.22 (d, J ¼ 8:4 Hz, 1H), 4.02 (dd, J ¼ 6:9, 4.8 Hz,

1H), 4.00–3.73 (m, 2H), 2.39 (s, 3H), 1.01 (d, J ¼ 4:3 Hz, 3H).

¹³C NMR (68 MHz, CDCl₃) ꢁ 202.1, 143.4, 141.4, 137.5, 137.1,

133.2, 129.6, 128.5, 128.3, 128.3, 127.4, 127.0, 125.8, 72.7,

57.2, 50.1, 21.5, 19.8. HRMS (ESI) calcd for C₂₄H₂₆NO₄S ½M þ

Hꢃ^þ424.1583, found 424.1564.

Experimental

General. Infrared (IR) spectra were recorded on a JASCO FT-

IR-8900 spectrometer. ¹H NMR spectra were recorded on a JEOL

JNM EX270L (270 MHz) spectrometer; chemical shifts (ꢁ) are re-

ported in parts per million relative to tetramethylsilane. Splitting

patterns are designated as s, singlet; d, doublet; t, triplet; q, quar-

tet; m, multiplet; br, broad. ¹³C NMR spectra were recorded on

EX270L (68 MHz) spectrometer with complete proton decou-

pling. Chemical shifts are reported in parts per million relative

to tetramethylsilane, with the solvent resonance as the internal

standard (CDCl₃; ꢁ ¼ 77:0 ppm). The optical rotations were mea-

sured with a JASCO P-1020 polarimeter. High-resolution mass

spectra (HRMS) were recorded on a JMS-700 mass spectrometer.

Analytical TLC was performed on Merck preparative TLC plates

(silica gel 60 GF254, 0.25 mm). Column chromatography was car-

ried out on Merck silica gel 60 (0.063–0.200 mm). Preparative

thin-layer chromatography (PTLC) was carried out on silica gel

Wakogel B-5F. All reactions were carried out under an argon at-

mosphere in dried glassware, unless otherwise noted. Dry solvents

were prepared by distillation under appropriate drying agents.

All reagents were purchased from Tokyo Kasei Kogyo, Kanto

Chemical, Kokusan Chemical, Wako Pure Chemical Industries, or

Aldrich Chemical. Samarium iodide THF solution (0.1 M) was

prepared from samarium metal and diiodomethane according to

the literature method.²⁶Aldehydes were used after puriﬁcation

by distillation or recrystallizaion.

anti,anti-1a: Colorless oil. IR (neat) 3486, 3324, 1650, 1332,

1

1160 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 7.85 (d, J ¼ 8:7 Hz,

2H), 7.69 (d, J ¼ 8:3 Hz, 2H), 7.56 (t, J ¼ 8:3 Hz, 1H), 7.53–

7.23 (m, 9H), 5.74 (d, J ¼ 9:0 Hz, 1H), 5.20 (d, J ¼ 7:4 Hz,

1H), 3.94 (dd, J ¼ 7:4, 4.3 Hz, 1H), 3.66–3.55 (m, 1H), 2.80

(brs, 1H), 2.41 (s, 3H), 0.96 (d, J ¼ 6:8 Hz, 3H). ¹³C NMR (68

MHz, CDCl₃) ꢁ 204.2, 143.0, 141.4, 138.6, 138.2, 133.5, 129.4,

128.5, 128.5, 128.3, 128.1, 126.6, 126.3, 74.1, 56.3, 50.0, 21.5,

20.4. HRMS (ESI) calcd for C₂₄H₂₆NO₄S ½M þ Hꢃ^þ424.1583,

found 424.1580.

anti,anti-1b: Colorless oil. IR (neat) 3490, 3310, 1664, 1250,

1

1159 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 7.88 (d, J ¼ 8:7 Hz,

2H), 7.68 (d, J ¼ 8:3 Hz, 2H), 7.55 (t, J ¼ 8:3 Hz, 1H), 7.43 (t,

J ¼ 8:3 Hz, 2H), 7.36–7.16 (m, 4H), 6.84 (d, J ¼ 8:3 Hz, 2H),

5.85 (d, J ¼ 8:9 Hz, 1H), 5.15 (d, J ¼ 7:8 Hz, 1H), 3.89 (dd, J ¼

7:8; 3:8 Hz, 1H), 3.80 (s, 3H), 3.58–3.47 (m, 1H), 2.63 (brs, 1H),

2.40 (s, 3H), 0.91 (d, J ¼ 6:8 Hz, 3H). ¹³C NMR (68 MHz,

CDCl₃) ꢁ 204.6, 159.3, 143.0, 138.8, 138.3, 133.6, 133.5, 129.5,

128.5, 128.4, 127.7, 126.7, 113.8, 73.8, 56.4, 55.2, 49.9, 21.6,

20.5. HRMS (ESI) calcd for C₂₅H₂₇NNaO₅S ½M þ Naꢃ^þ

476.1508, found 476.1517.

syn,anti-1c: Colorless oil. IR (neat) 3484, 3265, 1666, 1328,

1

trans-2-Benzoyl-3-methyl-1-tosylaziridine (1). To a suspen-

sion of 1-phenyl-2-buten-1-one (2.74 g, 18.8 mmol) and PhI=NTs

(1.40 g, 3.75 mmol) in dry CH₃CN (50 mL) at room temperature

under an argon atmosphere was added [Cu(acac)₂] (98 mg, 0.38

mmol). After the reaction mixture was stirred for 4 h, the reaction

mixture was ﬁltered through a short pad of silica gel with EtOAc

as eluent. After evaporation of the solvent under reduced pressure,

the crude product was puriﬁed by column chromatography to af-

ford trans-2-benzoyl-3-methyl-1-tosylaziridine (1) (709 mg,

1160 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 7.77 (d, J ¼ 8:7 Hz,

2H), 7.66 (d, J ¼ 8:4 Hz, 2H), 7.57 (t, J ¼ 8:4 Hz, 1H), 7.43 (t,

J ¼ 7:9 Hz, 2H), 7.19 (d, J ¼ 8:7 Hz, 2H), 5.45 (d, J ¼ 8:6 Hz,

1H), 4.00–3.89 (m, 2H), 3.56–3.45 (m, 2H), 2.38 (s, 3H), 1.38

(qd, J ¼ 7:3, 5.1 Hz, 2H), 1.15 (d, J ¼ 6:6 Hz, 3H), 0.91 (t, J ¼

7:3 Hz, 3H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 202.4, 143.1, 137.6,

137.0, 133.6, 129.5, 128.6, 128.2, 126.9, 72.4, 53.8, 50.6, 29.1,

21.6, 20.9, 10.9. HRMS (ESI) calcd for C₂₀H₂₆NO₄S ½M þ Hꢃ^þ

376.1583, found 376.1586.

60%). IR (neat) 1690, 1326, 1162 cm^ꢁ1

.

¹H NMR (270 MHz,

anti,anti-1c: Colorless oil. IR (neat) 3503, 3284, 1662, 1332,

1

CDCl₃) ꢁ 7.94 (d, J ¼ 8:2 Hz, 2H), 7.84 (d, J ¼ 8:2 Hz, 2H),

7.57 (t, J ¼ 7:6 Hz, 1H), 7.40 (t, J ¼ 7:6 Hz, 2H), 7.24 (d, J ¼

7:6 Hz, 2H), 4.16 (d, J ¼ 3:9 Hz, 1H), 3.25 (dq, J ¼ 3:9, 5.9

Hz, 1H), 2.35 (s, 3H), 1.82 (d, J ¼ 5:9 Hz, 3H). ¹³C NMR (68

MHz, CDCl₃) ꢁ 191.2, 144.1, 136.6, 135.3, 133.7, 129.3, 128.5,

128.2, 127.1, 46.8, 45.2, 21.5, 13.6. HRMS (ESI) calcd for

C₁₇H₁₈NO₃S ½M þ Hꢃ^þ316.1007, found 316.1001.

1159 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 7.88 (d, J ¼ 8:6 Hz,

2H), 7.69 (d, J ¼ 8:4 Hz, 2H), 7.56 (t, J ¼ 8:4 Hz, 1H), 7.44 (t,

J ¼ 7:9 Hz, 2H), 7.24 (d, J ¼ 8:7 Hz, 2H), 5.67 (d, J ¼ 9:0 Hz,

1H), 3.92–3.65 (m, 2H), 3.64 (t, J ¼ 5:8 Hz, 1H), 2.69 (d, J ¼

7:1 Hz, 1H), 2.39 (s, 3H), 1.42 (qd, J ¼ 7:3, 4.3 Hz, 2H), 1.05

(d, J ¼ 6:6 Hz, 3H), 0.86 (t, J ¼ 7:3 Hz, 3H). ¹³C NMR (68

MHz, CDCl₃) ꢁ 205.0, 143.1, 138.2, 138.1, 133.6, 129.5, 128.6,

1318 Bull. Chem. Soc. Jpn., 78, No. 7 (2005)

SmI₂-Mediated Aldol Reactions of Acylaziridines

128.4, 126.8, 73.1, 54.2, 50.2, 28.5, 21.6, 20.6, 10.1. HRMS (ESI)

calcd for C₂₀H₂₆NO₄S ½M þ Hꢃ^þ376.1583, found 376.1586.

syn,anti-1d: Colorless oil. IR (neat) 3443, 3216, 1664, 1328,

26.3, 26.0, 25.9, 21.6, 20.8. HRMS (ESI) calcd for C₂₄H₃₂NO₄S

½M þ Hꢃ^þ430.2052, found 430.2044.

Carbamate 2. To a solution of syn,anti-1d (22.2 mg, 0.0492

mmol) and pyridine (163 mg, 2.06 mmol) in CH₂Cl₂(7 mL) was

added triphosgene (72.9 mg, 0.246 mmol) at 0 ^ꢂC. After the reac-

1

1161 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 7.74 (d, J ¼ 8:6 Hz,

2H), 7.66 (d, J ¼ 8:2 Hz, 2H), 7.56 (t, J ¼ 8:4 Hz, 1H), 7.40 (t,

J ¼ 7:9 Hz, 2H), 7.26–7.04 (m, 7H), 5.47 (d, J ¼ 8:6 Hz, 1H),

4.17–4.12 (m, 1H), 4.07–3.88 (m, 1H), 3.67 (d, J ¼ 9:2 Hz,

1H), 3.51 (dd, J ¼ 6:6, 2.5 Hz, 1H), 2.83–2.75 (m, 1H), 2.65–

2.56 (m, 1H), 2.38 (s, 3H), 1.75–1.58 (m, 2H), 1.11 (d, J ¼ 6:8

Hz, 3H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 202.4, 143.1, 141.3,

137.4, 136.9, 133.7, 129.5, 128.6, 128.3, 128.3, 128.2, 126.9,

125.8, 70.3, 54.1, 50.5, 37.7, 32.6, 21.6, 20.9. HRMS (ESI) calcd

for C₂₆H₃₀NO₄S ½M þ Hꢃ^þ452.1896, found 452.1884.

ꢂ

tion mixture was stirred for 1 h at 0 C, the reaction mixture was

quenched with saturated aqueous ammonium chloride and was di-

luted with ethyl acetate. It was extracted with ethyl acetate, and

the organic layer was washed with brine and dried over anhydrous

sodium sulfate. After evaporation of the solvent under reduced

pressure, the crude product was puriﬁed by thin-layer chromatog-

raphy to aﬀord carbamate 2 (21.6 mg, 92%). Colorless oil. IR

(neat) 1723, 1679, 1358, 1221 cm^ꢁ1. ¹H NMR (270 MHz, CDCl₃)

ꢁ 7.76 (d, J ¼ 6:7 Hz, 2H), 7.73 (d, J ¼ 6:6 Hz, 2H), 7.57 (t, J ¼

7:3 Hz, 1H), 7.44 (t, J ¼ 6:3 Hz, 2H), 7.22–7.02 (m, 5H), 6.95 (d,

J ¼ 6:4 Hz, 2H), 4.75 (qd, J ¼ 6:6, 2.3 Hz, 1H), 4.60 (dt, J ¼ 9:4,

3.8 Hz, 1H), 3.66 (t, J ¼ 3:1 Hz, 1H), 2.76–2.64 (m, 1H), 2.59–

2.46 (m, 1H), 2.37 (s, 3H), 2.01–1.85 (m, 1H), 1.69–1.58 (m,

1H), 1.57 (d, J ¼ 6:4 Hz, 3H). ¹³C NMR (68 MHz, CDCl₃) ꢁ

196.1, 147.9, 144.7, 139.8, 135.8, 135.2, 134.1, 129.2, 129.1,

128.9, 128.4, 128.3, 128.1, 126.2, 74.7, 53.2, 45.9, 33.6, 31.5,

23.0, 21.8. HRMS (ESI) calcd for C₂₇H₂₈NO₅S ½M þ Hꢃ^þ

478.1688, found 478.1681.

anti,anti-1d: Colorless oil. IR (neat) 3495, 3313, 1649, 1332,

1

1160 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 7.86 (d, J ¼ 8:4 Hz,

2H), 7.69 (d, J ¼ 8:2 Hz, 2H), 7.58 (t, J ¼ 8:4 Hz, 1H), 7.44 (t,

J ¼ 7:9 Hz, 2H), 7.27–7.08 (m, 7H), 5.57 (d, J ¼ 9:2 Hz, 1H),

4.08–4.02 (m, 1H), 3.89–3.82 (m, 1H), 3.64 (t, J ¼ 5:6 Hz, 1H),

2.89 (d, J ¼ 8:1 Hz, 1H), 2.79–2.72 (m, 1H), 2.60–2.37 (m,

1H), 2.38 (s, 3H), 1.79–1.65 (m, 2H), 1.03 (d, J ¼ 6:8 Hz, 3H).

¹³C NMR (68 MHz, CDCl₃) ꢁ 204.8, 143.2, 141.3, 138.0, 137.9,

133.7, 129.5, 128.7, 128.4, 128.3, 128.2, 126.8, 125.8, 71.4,

54.4, 50.3, 37.3, 32.1, 21.6, 20.4. HRMS (ESI) calcd for

C₂₆H₃₀NO₄S ½M þ Hꢃ^þ452.1896, found 452.1892.

Carbamate 3. To a solution of anti,anti-1d (28.8 mg, 0.0638

mmol) and pyridine (212 mg, 2.68 mmol) in CH₂Cl₂(8 mL) was

added triphosgene (94.6 mg, 0.319 mmol) at 0 ^ꢂC. After the reac-

syn,anti-1e: Colorless oil. IR (neat) 3452, 3216, 1664, 1328,

1

1159 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 7.82 (d, J ¼ 8:2 Hz,

ꢂ

2H), 7.62–7.54 (m, 3H), 7.42 (t, J ¼ 8:4 Hz, 2H), 7.14 (d, J ¼

8:1 Hz, 2H), 5.63 (d, J ¼ 8:4 Hz, 1H), 3.95–3.83 (m, 1H),

3.70–3.64 (m, 3H), 2.37 (s, 3H), 1.66–1.57 (m, 1H), 1.24 (d, J ¼

6:8 Hz, 3H), 0.98 (d, J ¼ 6:6 Hz, 3H), 0.76 (d, J ¼ 6:6 Hz, 3H).

¹³C NMR (68 MHz, CDCl₃) ꢁ 202.9, 142.9, 137.7, 136.5, 133.7,

129.3, 128.6, 128.2, 126.9, 76.9, 51.0, 50.3, 33.0, 21.6, 21.0,

19.8, 19.4. HRMS (ESI) calcd for C₂₁H₂₈NO₄S ½M þ Hꢃ^þ

390.1739, found 390.1737.

tion mixture was stirred for 1 h at 0 C, the reaction mixture was

quenched with saturated aqueous ammonium chloride and was di-

luted with ethyl acetate. It was extracted with ethyl acetate, and

the organic layer was washed with brine and dried over anhydrous

sodium sulfate. After evaporation of the solvent under reduced

pressure, the crude product was puriﬁed by thin-layer chromatog-

raphy to aﬀord carbamate 3 (21.4 mg, 70%). Colorless oil. IR

(neat) 1730, 1672, 1223 cm^ꢁ^{1 1}H NMR (270 MHz, CDCl₃) ꢁ

.

anti,anti-1e: Colorless oil. IR (neat) 3456, 3283, 1661, 1332,

1

8.02 (d, J ¼ 7:3 Hz, 2H), 7.83 (d, J ¼ 7:3 Hz, 2H), 7.62 (t, J ¼

7:3 Hz, 1H), 7.48 (t, J ¼ 7:3 Hz, 2H), 7.35–7.14 (m, 5H), 6.98

(d, J ¼ 7:4 Hz, 2H), 4.82 (quintet, J ¼ 6:5 Hz, 1H), 4.58 (dt,

J ¼ 10:0, 3.8 Hz, 1H), 4.24 (dd, J ¼ 6:1, 3.6 Hz, 1H), 2.85–

2.72 (m, 1H), 2.68–2.55 (m, 1H), 2.44 (s, 3H), 1.96–1.82 (m,

1H), 1.80–1.65 (m, 1H), 1.43 (d, J ¼ 6:4 Hz, 3H). ¹³C NMR (68

MHz, CDCl₃) ꢁ 196.4, 149.5, 144.7, 139.6, 137.5, 136.5, 134.0,

129.4, 129.1, 128.6, 128.5, 128.3, 128.0, 126.2, 76.9, 54.9, 47.2,

34.2, 31.6, 21.7, 18.7. HRMS (ESI) calcd for C₂₇H₂₈NO₅S ½M þ

Hꢃ^þ478.1688, found 478.1718.

1159 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 7.91 (d, J ¼ 8:2 Hz,

2H), 7.68 (d, J ¼ 8:2 Hz, 2H), 7.58 (t, J ¼ 8:4 Hz, 1H), 7.45 (t,

J ¼ 8:1 Hz, 2H), 7.25 (t, J ¼ 8:1 Hz, 2H), 5.73 (d, J ¼ 8:4 Hz,

1H), 3.84–3.70 (m, 3H), 2.80 (d, J ¼ 7:2 Hz, 1H), 2.37 (s, 3H),

1.66–1.57 (m, 1H), 1.07 (d, J ¼ 6:1 Hz, 3H), 0.91 (d, J ¼ 6:6

Hz, 3H), 0.77 (d, J ¼ 6:8 Hz, 3H). ¹³C NMR (68 MHz, CDCl₃)

ꢁ 205.5, 143.1, 138.1, 133.6, 129.4, 128.6, 128.4, 126.8, 76.3,

51.3, 50.2, 31.1, 21.5, 20.6, 19.7, 16.6. HRMS (ESI) calcd for

C₂₁H₂₇NNaO₄S ½M þ Naꢃ^þ412.1559, found 412.1550.

syn,anti-1f: Colorless oil. IR (neat) 3507, 3237, 1665, 1333,

Typical Procedure for the Preparation of N-Tosylaziridinyl

Ketone. N–H aziridines were prepared from corresponding the

ꢃ,ꢀ-unsaturated ketones according to the literature procedure.¹²

To a solution of 2-benzoyl-3-propyl-1H-aziridine (480 mg, 2.54

mmol) and DMAP (776 mg, 6.35 mmol)_ꢂin CH₂Cl₂(10 mL)

was added TsCl (726 mg, 3.81 mmol) at 0 C. After the reaction

mixture was stirred for 1 h at 0 ^ꢂC, the reaction mixture was

quenched with saturated aqueous ammonium chloride and was di-

luted with ethyl acetate. It was extracted with ethyl acetate, and

the organic layer was washed with brine and dried over anhydrous

sodium sulfate. After evaporation of the solvent under reduced

pressure, the crude product was puriﬁed by column chromatogra-

phy to aﬀord trans-2-benzoyl-3-propyl-1-tosylaziridine (4) (691

mg, 79%).

1

1160 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 7.72 (d, J ¼ 8:2 Hz,

2H), 7.61–7.55 (m, 3H), 7.42 (t, J ¼ 8:1 Hz, 2H), 7.13 (d, J ¼

8:1 Hz, 2H), 5.72 (d, J ¼ 8:6 Hz, 1H), 3.95–3.86 (m, 1H),

3.77–3.63 (m, 3H), 2.37 (s, 3H), 2.08–2.01 (m, 1H), 1.75–1.58

(m, 2H), 1.47–1.20 (m, 3H), 1.22 (d, J ¼ 6:1 Hz, 3H), 1.15–

0.84 (m, 5H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 202.7, 142.7,

137.7, 136.2, 133.5, 129.2, 128.5, 128.1, 126.7, 75.9, 51.0, 49.6,

42.3, 29.9, 29.5, 26.1, 25.8, 25.7, 21.5, 21.1. HRMS (ESI) calcd

for C₂₄H₃₂NO₄S ½M þ Hꢃ^þ430.2052, found 430.2044.

anti,anti-1f: Colorless oil. IR (neat) 3499, 3304, 1653, 1335,

1

1164 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 7.91 (d, J ¼ 8:2 Hz,

2H), 7.70 (d, J ¼ 8:0 Hz, 2H), 7.58 (t, J ¼ 8:2 Hz, 1H), 7.46 (t,

J ¼ 8:1 Hz, 2H), 7.24 (d, J ¼ 8:1 Hz, 2H), 5.72 (d, J ¼ 8:6 Hz,

1H), 3.85–3.65 (m, 3H), 2.75 (d, J ¼ 7:7 Hz, 1H), 2.37 (s, 3H),

1.77–1.58 (m, 4H), 1.29–0.98 (m, 7H), 1.10 (d, J ¼ 6:1 Hz,

3H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 205.5, 143.1, 138.1, 133.6,

129.5, 128.7, 128.4, 126.8, 75.6, 50.7, 50.1, 40.9, 29.9, 26.9,

trans-2-Benzoyl-3-propyl-1-tosylaziridine (4): Colorless oil.

1

IR (neat) 1689, 1328, 1161 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ

7.97 (d, J ¼ 8:2 Hz, 2H), 7.83 (d, J ¼ 8:2 Hz, 2H), 7.60 (t, J ¼

7:6 Hz, 1H), 7.40 (t, J ¼ 7:6 Hz, 2H), 7.26 (d, J ¼ 7:6 Hz, 2H),

Y. Ogawa et al.

Bull. Chem. Soc. Jpn., 78, No. 7 (2005) 1319

4.11 (d, J ¼ 4:1 Hz, 1H), 3.23–3.15 (m, 1H), 2.39 (s, 3H), 2.32–

2.15 (m, 1H), 2.10–1.95 (m, 1H), 1.63–1.48 (m, 2H), 0.99 (t, J ¼

7:3 Hz, 3H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 191.4, 144.3, 136.8,

135.6, 133.9, 129.5, 128.7, 128.5, 127.5, 49.8, 46.8, 30.4, 21.7,

21.2, 13.9. HRMS (ESI) calcd for C₁₉H₂₂NO₃S ½M þ Hꢃ^þ

344.1320, found 344.1319.

layer chromatography to aﬀord anti,anti-5a (78.0 mg, 98%).

syn,anti-4a: Colorless oil. IR (neat) 3464, 3222, 1661, 1326,

1

1154 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 7.70 (d, J ¼ 8:2 Hz,

2H), 7.61–7.52 (m, 3H), 7.38 (t, J ¼ 8:2 Hz, 2H), 7.26–7.05 (m,

7H), 5.46 (d, J ¼ 8:6 Hz, 1H), 4.15–4.02 (m, 1H), 3.87–3.65

(m, 2H), 3.59 (dd, J ¼ 5:5, 2.6 Hz, 1H), 2.90–2.75 (m, 1H),

2.68–2.42 (m, 1H), 2.38 (s, 3H), 1.81–1.75 (m, 1H), 1.70–1.47

(m, 3H), 1.27–0.93 (m, 2H), 0.73 (t, J ¼ 7:3 Hz, 3H). ¹³C NMR

(68 MHz, CDCl₃) ꢁ 202.8, 142.9, 141.3, 137.9, 136.7, 133.7,

129.3, 128.6, 128.3, 128.3, 126.9, 125.8, 70.5, 55.1, 51.5, 38.0,

36.7, 32.5, 21.6, 19.3, 13.7. HRMS (ESI) calcd for C₂₈H₃₄NO₄S

½M þ Hꢃ^þ480.2209, found 480.2217.

trans-2-Benzoyl-3-isopropyl-1-tosylaziridine (5): Colorless

oil. IR (neat) 1685, 1329, 1164 cm^ꢁ^{1 1}H NMR (270 MHz,

.

CDCl₃) ꢁ 7.96 (d, J ¼ 8:2 Hz, 2H), 7.77 (d, J ¼ 8:2 Hz, 2H),

7.54 (t, J ¼ 7:6 Hz, 1H), 7.42 (t, J ¼ 7:6 Hz, 2H), 7.19 (d, J ¼

7:6 Hz, 2H), 4.04 (d, J ¼ 4:1 Hz, 1H), 3.17 (dd, J ¼ 8:7, 4.1

Hz, 1H), 2.31 (s, 3H), 2.15–2.04 (m, 1H), 1.09 (d, J ¼ 6:4 Hz,

3H), 1.02 (d, J ¼ 6:6 Hz, 3H). ¹³C NMR (68 MHz, CDCl₃) ꢁ

190.5, 143.8, 136.2, 135.3, 133.4, 129.0, 128.2, 128.1, 127.1,

54.2, 46.6, 28.5, 21.1, 20.3, 20.1. HRMS (ESI) calcd for

C₁₉H₂₂NO₃S ½M þ Hꢃ^þ344.1320, found 344.1305.

anti,anti-4a: Colorless oil. IR (neat) 3484, 3294, 1667, 1329,

1

1157 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 7.88 (d, J ¼ 8:2 Hz,

2H), 7.71 (d, J ¼ 8:0 Hz, 2H), 7.57 (t, J ¼ 8:2 Hz, 1H), 7.45 (t,

J ¼ 8:1 Hz, 2H), 7.27–7.10 (m, 7H), 5.73 (d, J ¼ 8:4 Hz, 1H),

4.15–4.05 (m, 1H), 3.82–3.72 (m, 2H), 3.07 (d, J ¼ 7:7 Hz,

1H), 2.80–2.72 (m, 1H), 2.57–2.48 (m, 1H), 2.37 (s, 3H), 1.82–

1.73 (m, 2H), 1.42–1.23 (m, 2H), 1.11–0.91 (m, 2H), 0.61 (t, J ¼

7:3 Hz, 3H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 204.9, 143.1, 141.5,

138.2, 137.8, 133.7, 129.4, 128.7, 128.3, 128.3, 128.2, 126.7,

125.7, 71.2, 54.4, 52.6, 37.6, 35.8, 32.1, 21.5, 19.2, 13.5. HRMS

(ESI) calcd for C₂₈H₃₄NO₄S ½M þ Hꢃ^þ480.2209, found

480.2207.

trans-2-Benzoyl-3-t-butyl-1-tosylaziridine (6): Colorless oil.

1

IR (neat) 1687, 1318, 1159 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ

8.03 (d, J ¼ 8:2 Hz, 2H), 7.72 (d, J ¼ 8:2 Hz, 2H), 7.57 (t, J ¼

7:6 Hz, 1H), 7.46 (t, J ¼ 7:6 Hz, 2H), 7.24 (d, J ¼ 7:6 Hz, 2H),

3.80 (d, J ¼ 4:4 Hz, 1H), 3.47 (d, J ¼ 4:4 Hz, 1H), 2.42 (s,

3H), 0.87 (s, 9H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 190.1, 143.9,

136.2, 135.9, 133.4, 129.0, 128.6, 128.2, 127.6, 52.9, 46.7, 30.4,

26.1, 21.4. HRMS (ESI) calcd for C₂₀H₂₃NNaO₃S ½M þ Naꢃ^þ

380.1296, found 380.1281.

syn,anti-4b: Colorless oil. IR (neat) 3493, 3282, 1667, 1328,

1

trans-2-Benzoyl-3-phenyl-1-tosylaziridine (7): Colorless oil.

1

1158 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 7.70 (d, J ¼ 8:2 Hz,

IR (neat) 1686, 1322, 1160 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ

2H), 7.61–7.52 (m, 3H), 7.38 (t, J ¼ 8:2 Hz, 2H), 7.11 (d, J ¼

7:9 Hz, 2H), 5.72 (d, J ¼ 8:3 Hz, 1H), 3.83–3.74 (m, 2H),

3.63–3.52 (m, 1H), 2.37 (s, 3H), 1.73–1.60 (m, 2H), 1.32–1.16

(m, 3H), 0.99 (d, J ¼ 6:6 Hz, 3H), 0.84 (t, J ¼ 7:3 Hz, 3H),

0.77 (d, J ¼ 6:8 Hz, 3H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 203.1,

142.7, 138.0, 136.3, 133.7, 129.2, 128.6, 128.2, 126.9, 77.3,

55.5, 47.4, 36.8, 33.2, 21.6, 19.8, 19.7, 19.4, 13.8. HRMS (ESI)

calcd for C₂₃H₃₂NO₄S ½M þ Hꢃ^þ418.2052, found 418.2047.

anti,anti-4b: Colorless oil. IR (neat) 3501, 3294, 1662, 1333,

8.04 (d, J ¼ 8:2 Hz, 2H), 7.71 (d, J ¼ 8:2 Hz, 2H), 7.59 (t, J ¼

7:6 Hz, 1H), 7.48 (t, J ¼ 7:6 Hz, 2H), 7.35–7.18 (m, 7H), 4.51

(d, J ¼ 4:1 Hz, 1H), 4.28 (d, J ¼ 4:1 Hz, 1H), 2.39 (s, 3H).

¹³C NMR (68 MHz, CDCl₃) ꢁ 190.1, 144.2, 136.5, 135.8, 134.0,

132.8, 129.4, 128.8, 128.8, 128.7, 128.5, 127.6, 127.4, 50.2,

47.5, 21.7. HRMS (ESI) calcd for C₂₂H₂₀NO₃S ½M þ Hꢃ^þ

378.1164, found 378.1201.

trans-2-Benzoyl-1-tosylaziridine (8): Colorless oil. IR (neat)

1691, 1315, 1233, 1163 cm^ꢁ1. ¹H NMR (270 MHz, CDCl₃) ꢁ 7.98

(d, J ¼ 8:2 Hz, 2H), 7.84 (d, J ¼ 8:2 Hz, 2H), 7.56 (t, J ¼ 7:6 Hz,

1H), 7.42 (t, J ¼ 7:6 Hz, 2H), 7.28 (d, J ¼ 7:6 Hz, 2H), 4.18 (dd,

J ¼ 6:9, 4.1 Hz, 1H), 2.87 (d, J ¼ 6:9 Hz, 1H), 2.71 (d, J ¼ 4:3

Hz, 1H), 2.35 (s, 3H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 190.7,

144.7, 135.0, 133.7, 133.6, 129.4, 128.3, 128.2, 127.6, 37.5,

32.4, 21.2. HRMS (ESI) calcd for C₁₆H₁₆NO₃S ½M þ Hꢃ^þ

302.0851, found 302.0863.

1

1159 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 7.93 (d, J ¼ 8:2 Hz,

2H), 7.70 (d, J ¼ 8:0 Hz, 2H), 7.58 (t, J ¼ 8:2 Hz, 1H), 7.46 (t,

J ¼ 8:1 Hz, 2H), 7.23 (d, J ¼ 7:7 Hz, 2H), 5.81 (d, J ¼ 8:6 Hz,

1H), 3.96 (t, J ¼ 5:4 Hz, 1H), 3.76 (t, J ¼ 5:6 Hz, 1H), 3.70–

3.61 (m, 1H), 2.39 (s, 3H), 1.72–1.62 (m, 1H), 1.55–1.41 (m,

1H), 1.39–1.25 (m, 1H), 1.19–1.08 (m, 1H), 1.04–0.95 (m, 1H),

0.92 (d, J ¼ 6:6 Hz, 3H), 0.76 (d, J ¼ 6:8 Hz, 3H), 0.64 (t, J ¼

6:9 Hz, 3H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 205.5, 142.9, 138.3,

138.0, 133.5, 129.3, 128.6, 128.3, 126.7, 75.9, 54.2, 49.4, 36.0,

31.2, 21.5, 19.6, 19.2, 16.5, 13.5. HRMS (ESI) calcd for

C₂₃H₃₂NO₄S ½M þ Hꢃ^þ418.2052, found 418.2061.

trans-2-Acetyl-3-phenyl-1-tosylaziridine (9): Colorless oil.

IR (neat) 1725, 1333, 1163 cm^ꢁ^{1 1}H NMR (270 MHz, CDCl₃)

.

ꢁ 7.69 (d, J ¼ 8:2 Hz, 2H), 7.31–7.20 (m, 7H), 4.26 (d, J ¼ 4:1

Hz, 1H), 3.73 (d, J ¼ 4:1 Hz, 1H), 2.38 (s, 3H), 2.31 (s, 3H).

¹³C NMR (68 MHz, CDCl₃) ꢁ 200.0, 144.2, 136.3, 131.4, 129.4,

128.8, 128.2, 127.8, 127.2, 50.9, 48.6, 28.4, 21.5. HRMS (ESI)

calcd for C₁₇H₁₈NO₃S ½M þ Hꢃ^þ316.1007, found 316.0993.

Typical Procedure for Samarium(II) Iodide-Mediated Aldol

Reaction of Aziridinyl Ketone with Aldehyde. (Table 3, Entry

3). To a mixture of trans-2-benzoyl-3-isopropyl-1-tosylaziridine

(5) (60.5 mg, 0.176 mmol) and 3-phenylpropanal (26.0 mg, 0.193

mmol) in THF (4 mL) at ꢁ78 ^ꢂC under an argon atmosphere was

added a solution of SmI₂in THF (0.1 M, 4.4 mL, 0.44 mmol). Af-

ter the reaction mixture was stirred for 1 h at ꢁ78 ^ꢂC, the reaction

mixture was quenched with saturated aqueous ammonium chlo-

ride and was diluted with ethyl acetate. It was extracted with ethyl

acetate, and the organic layer was washed with brine and dried

over anhydrous sodium sulfate. After evaporation of the solvent

under reduced pressure, the crude product was puriﬁed by thin-

anti,anti-5a: Colorless oil. IR (neat) 3500, 3306, 1663, 1327,

1

1157 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 7.83 (d, J ¼ 8:2 Hz,

2H), 7.70 (d, J ¼ 8:0 Hz, 2H), 7.54 (t, J ¼ 8:2 Hz, 1H), 7.41 (t,

J ¼ 8:1 Hz, 2H), 7.29–7.12 (m, 7H), 5.98 (d, J ¼ 8:7 Hz, 1H),

4.12–4.00 (m, 1H), 3.79 (dd, J ¼ 6:6, 4.6 Hz, 1H), 3.71 (dd,

J ¼ 8:9, 6.1 Hz, 1H), 2.82–2.52 (m, 1H), 2.60–2.50 (m, 1H),

2.48 (d, J ¼ 6:9 Hz, 1H), 2.37 (s, 3H), 1.94–1.73 (m, 3H), 0.74

(d, J ¼ 6:9 Hz, 6H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 205.3,

142.7, 141.4, 138.8, 138.3, 133.4, 129.2, 128.5, 128.4, 128.3,

128.2, 126.6, 125.7, 72.1, 60.3, 50.2, 37.5, 31.9, 31.9, 21.5,

19.9, 18.8. HRMS (ESI) calcd for C₂₈H₃₄NO₄S ½M þ Hꢃ^þ

480.2209, found 480.2209.

anti,anti-5b: Colorless oil. IR (neat) 3518, 3306, 1665, 1330,

1

1158 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 7.84 (d, J ¼ 8:2 Hz,

2H), 7.69 (d, J ¼ 8:0 Hz, 2H), 7.56 (t, J ¼ 8:2 Hz, 1H), 7.43 (t,

J ¼ 8:1 Hz, 2H), 7.20 (d, J ¼ 8:1 Hz, 2H), 6.12 (d, J ¼ 8:7 Hz,

1320 Bull. Chem. Soc. Jpn., 78, No. 7 (2005)

SmI₂-Mediated Aldol Reactions of Acylaziridines

1H), 3.93 (dd, J ¼ 7:6, 4.5 Hz, 1H), 3.70–3.58 (m, 2H), 2.60–2.50

(m, 1H), 2.38 (s, 3H), 2.07 (d, J ¼ 6:4 Hz, 1H), 1.85–1.69 (m,

2H), 0.93 (d, J ¼ 6:8 Hz, 3H), 0.84 (d, J ¼ 6:8 Hz, 3H), 0.77

(d, J ¼ 6:8 Hz, 3H), 0.72 (d, J ¼ 6:8 Hz, 3H). ¹³C NMR (68

MHz, CDCl₃) ꢁ 206.0, 142.6, 139.0, 138.6, 133.3, 129.2, 128.5,

128.3, 126.5, 76.5, 59.9, 46.7, 32.2, 30.3, 21.5, 19.7, 19.5, 18.8,

15.5. HRMS (ESI) calcd for C₂₃H₃₂NO₄S ½M þ Hꢃ^þ418.2052,

found 418.2079.

syn,anti-7b: Colorless oil. IR (neat) 3474, 3226, 1669, 1319,

1

1158 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 7.73 (d, J ¼ 8:2 Hz,

2H), 7.59 (t, J ¼ 8:0 Hz, 1H), 7.47–7.37 (m, 4H), 7.26–7.15 (m,

5H), 6.95 (d, J ¼ 8:2 Hz, 2H), 6.74 (d, J ¼ 8:9 Hz, 1H), 5.04

(dd, J ¼ 8:9, 4.8 Hz, 1H), 3.93 (d, J ¼ 10:7 Hz, 1H), 3.82 (dd,

J ¼ 4:8, 1.8 Hz, 1H), 3.40–3.29 (m, 1H), 2.30 (s, 3H), 1.70–

1.55 (m, 1H), 0.87 (d, J ¼ 6:8 Hz, 3H), 0.60 (d, J ¼ 6:8 Hz,

3H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 201.9, 142.4, 138.9, 137.3,

135.8, 133.6, 128.9, 128.6, 128.4, 128.0, 127.3, 126.7, 126.3,

76.6, 58.5, 50.4, 33.1, 21.4, 19.5, 19.5. HRMS (ESI) calcd for

C₂₆H₃₀NO₄S ½M þ Hꢃ^þ452.1896, found 452.1901.

anti,anti-6a: Colorless oil. IR (neat) 3517, 3286, 1664, 1325,

1

1155 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 7.94 (d, J ¼ 8:2 Hz,

2H), 7.81 (d, J ¼ 8:0 Hz, 2H), 7.56 (t, J ¼ 8:2 Hz, 1H), 7.45 (t,

J ¼ 8:1 Hz, 2H), 7.32–7.17 (m, 7H), 7.04 (d, J ¼ 8:1 Hz, 1H),

4.18 (brs, 1H), 3.92 (d, J ¼ 8:1 Hz, 1H), 3.65 (d, J ¼ 6:8 Hz,

1H), 2.81–2.75 (m, 1H), 2.69–2.56 (m, 1H), 2.40 (s, 3H), 2.29

(d, J ¼ 5:1 Hz, 1H), 2.25–2.10 (m, 1H), 1.98–1.78 (m, 1H),

0.71 (s, 9H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 206.0, 142.7, 141.7,

139.3, 138.8, 133.3, 129.3, 128.6, 128.5, 128.4, 128.4, 126.5,

125.8, 73.5, 64.2, 48.2, 37.7, 36.5, 31.9, 27.9, 21.5. HRMS

(ESI) calcd for C₂₉H₃₆NO₄S ½M þ Hꢃ^þ494.2365, found

494.2330.

anti,anti-7b: Colorless oil. IR (neat) 3519, 3281, 1661, 1330,

1

1160 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 7.62 (d, J ¼ 7:6 Hz,

2H), 7.44–7.35 (m, 3H), 7.25 (t, J ¼ 7:6 Hz, 2H), 7.05–6.92 (m,

7H), 6.53 (d, J ¼ 9:2 Hz, 1H), 4.88 (dd, J ¼ 9:2, 6.5 Hz, 1H),

3.99 (t, J ¼ 6:5 Hz, 1H), 3.60–3.53 (m, 1H), 2.67 (brs, 1H),

2.29 (s, 3H), 1.81–1.70 (m, 1H), 0.92 (d, J ¼ 6:8 Hz, 3H), 0.79

(d, J ¼ 6:8 Hz, 1H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 205.3,

142.6, 138.7, 138.4, 137.4, 133.2, 128.9, 128.2, 128.2, 128.1,

127.2, 126.8, 126.3, 76.5, 58.1, 52.8, 30.6, 21.4, 19.6, 16.4. HRMS

(ESI) calcd for C₂₆H₃₀NO₄S ½M þ Hꢃ^þ452.1896, found

452.1904.

anti,anti-6b: Colorless oil. IR (neat) 3532, 3284, 1665, 1327,

1

1156 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 7.93 (d, J ¼ 8:2 Hz,

2H), 7.80 (d, J ¼ 8:0 Hz, 2H), 7.56 (t, J ¼ 8:2 Hz, 1H), 7.45 (t,

J ¼ 8:1 Hz, 2H), 7.27 (d, J ¼ 8:1 Hz, 2H), 7.04 (d, J ¼ 8:1 Hz,

1H), 4.06 (dd, J ¼ 9:4, 1.8 Hz, 1H), 3.92–3.86 (m, 1H), 3.58

(dd, J ¼ 8:2, 1.8 Hz, 1H), 2.40 (s, 3H), 2.16–2.09 (m, 1H), 1.69

(d, J ¼ 5:1 Hz, 1H), 1.00 (d, J ¼ 6:8 Hz, 3H), 0.87 (d, J ¼ 6:8

Hz, 3H), 0.76 (s, 9H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 207.0,

142.5, 139.6, 139.1, 133.1, 129.3, 128.6, 128.5, 126.4, 76.9,

63.4, 44.9, 36.6, 29.3, 27.9, 21.5, 19.5, 14.0. HRMS (ESI) calcd

for C₂₄H₃₄NO₄S ½M þ Hꢃ^þ432.2209, found 432.2229.

Other Isomer-7b: Colorless oil. IR (neat) 3486, 3290, 1660,

1319, 1158 cm^ꢁ1. ¹H NMR (270 MHz, CDCl₃) ꢁ 7.56 (d, J ¼ 8:2

Hz, 2H), 7.43–7.32 (m, 3H), 7.26–7.17 (m, 3H), 7.04–6.92 (m,

6H), 6.72 (d, J ¼ 9:6 Hz, 1H), 5.08 (dd, J ¼ 9:2, 3.1 Hz, 1H),

4.12–4.06 (m, 1H), 3.91 (dd, J ¼ 9:6, 3.5 Hz, 1H), 3.23 (d, J ¼

3:9 Hz, 1H), 2.26 (s, 3H), 1.43–1.27 (m, 1H), 0.96 (d, J ¼ 6:8

Hz, 1H), 0.74 (d, J ¼ 6:8 Hz, 1H). ¹³C NMR (68 MHz, CDCl₃)

ꢁ 204.1, 142.9, 138.7, 137.4, 136.9, 133.2, 129.0, 128.2, 128.0,

127.7, 126.9, 126.8, 125.8, 74.8, 56.1, 55.3, 30.7, 21.3, 20.7,

14.8. HRMS (ESI) calcd for C₂₆H₃₀NO₄S ½M þ Hꢃ^þ452.1896,

found 452.1885.

syn,anti-7a: Colorless oil. IR (neat) 3467, 3251, 1665, 1321,

1

1157 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 7.64 (d, J ¼ 8:2 Hz,

2H), 7.55 (t, J ¼ 8:0 Hz, 1H), 7.44–7.33 (m, 4H), 7.19–7.05 (m,

8H), 7.00–6.93 (m, 4H), 6.50 (d, J ¼ 8:7 Hz, 1H), 5.00 (dd,

J ¼ 8:7, 6.2 Hz, 1H), 4.05–3.80 (m, 2H), 3.69 (dd, J ¼ 6:1, 1.8

Hz, 1H), 2.78–2.66 (m, 1H), 2.53–2.40 (m, 1H), 2.29 (s, 3H),

1.83–1.57 (m, 2H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 201.6, 142.7,

141.1, 138.9, 137.2, 136.4, 133.5, 129.0, 128.6, 128.4, 128.2,

128.2, 128.0, 127.5, 126.9, 126.6, 125.7, 70.3, 58.3, 54.1, 37.8,

32.6, 21.5. HRMS (ESI) calcd for C₃₁H₃₂NO₄S ½M þ Hꢃ^þ

514.2052, found 514.2075.

anti-8a: Colorless oil. IR (neat) 3503, 3283, 1671, 1328, 1159

.

cm^ꢁ1

¹H NMR (270 MHz, CDCl₃) ꢁ 7.91 (d, J ¼ 8:2 Hz, 2H),

7.69 (d, J ¼ 8:0 Hz, 2H), 7.61 (t, J ¼ 8:0 Hz, 1H), 7.47 (t, J ¼

8:2 Hz, 2H), 7.26–7.10 (m, 5H), 7.08 (d, J ¼ 7:2 Hz, 2H), 5.12

(t, J ¼ 6:3 Hz, 1H), 4.00–3.84 (m, 2H), 3.42–3.27 (m, 2H), 2.96

(d, J ¼ 8:9 Hz, 1H), 2.86–2.73 (m, 1H), 2.64–2.51 (m, 1H),

2.40 (s, 3H), 1.75–1.58 (m, 2H). ¹³C NMR (68 MHz, CDCl₃) ꢁ

203.5, 143.3, 141.2, 136.6, 136.5, 133.9, 129.6, 128.7, 128.4,

128.2, 128.2, 126.8, 125.7, 71.0, 50.6, 42.5, 36.9, 32.3, 21.5.

HRMS (ESI) calcd for C₂₅H₂₈NO₄S ½M þ Hꢃ^þ438.1739, found

438.1755.

anti,anti-7a: Colorless oil. IR (neat) 3506, 3280, 1661, 1330,

1

1159 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 7.60 (d, J ¼ 8:2 Hz,

2H), 7.45–7.36 (m, 3H), 7.29–6.91 (m, 14H), 6.38 (d, J ¼ 9:6

Hz, 1H), 4.93 (dd, J ¼ 9:6, 6.3 Hz, 1H), 3.87–3.80 (m, 2H),

2.82–2.69 (m, 2H), 2.58–2.45 (m, 1H), 2.27 (s, 3H), 1.96–1.65

(m, 2H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 204.8, 142.7, 141.2,

138.4, 138.3, 137.3, 133.4, 128.9, 128.3, 128.3, 128.2, 128.1,

127.2, 126.9, 126.4, 125.8, 71.6, 58.2, 55.6, 37.1, 32.0, 21.4.

HRMS (ESI) calcd for C₃₁H₃₂NO₄S ½M þ Hꢃ^þ514.2052, found

514.2059.

anti-8b: Colorless oil. IR (neat) 3508, 3282, 1667, 1330, 1159

.

cm^ꢁ1

¹H NMR (270 MHz, CDCl₃) ꢁ 7.96 (d, J ¼ 8:2 Hz, 2H),

7.70 (d, J ¼ 8:0 Hz, 2H), 7.61 (t, J ¼ 8:0 Hz, 1H), 7.48 (t, J ¼

8:2 Hz, 2H), 7.25 (d, J ¼ 8:1 Hz, 2H), 5.59–5.47 (m, 1H),

4.05–3.97 (m, 1H), 3.56–3.46 (m, 1H), 3.37–3.06 (m, 3H), 2.40

(s, 3H), 1.67–1.56 (m, 1H), 0.96 (d, J ¼ 6:4 Hz, 3H), 0.77 (d, J ¼

6:8 Hz, 3H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 204.5, 143.3, 136.8,

136.6, 133.9, 129.6, 128.8, 128.4, 126.8, 77.2, 47.4, 43.3, 32.4,

21.5, 19.5, 18.7. HRMS (ESI) calcd for C₂₀H₂₆NO₄S ½M þ Hꢃ^þ

376.1583, found 376.1608.

Other Isomer-7a: Colorless oil. IR (neat) 3527, 3252, 1664,

1447, 1155 cm^ꢁ1. ¹H NMR (270 MHz, CDCl₃) ꢁ 7.56 (d, J ¼ 8:2

Hz, 2H), 7.42–7.32 (m, 3H), 7.30–6.91 (m, 14H), 6.72 (d, J ¼ 9:6

Hz, 1H), 5.11 (dd, J ¼ 9:9, 3.6 Hz, 1H), 4.35–4.26 (m, 1H), 3.87

(dd, J ¼ 9:4, 3.6 Hz, 1H), 3.69 (d, J ¼ 4:8 Hz, 1H), 2.94–2.81 (m,

1H), 2.70–2.57 (m, 1H), 2.27 (s, 3H), 1.67–1.42 (m, 2H).

¹³C NMR (68 MHz, CDCl₃) ꢁ 203.7, 143.0, 141.5, 138.4, 137.5,

136.8, 133.3, 129.0, 128.3, 128.1, 128.0, 127.8, 126.9, 126.8,

125.7, 125.6, 70.6, 57.8, 56.0, 37.0, 32.2, 21.4. HRMS (ESI) calcd

for C₃₁H₃₂NO₄S ½M þ Hꢃ^þ514.2052, found 514.2047.

syn,anti-9a: Colorless oil. IR (neat) 3483, 3278, 1701, 1328,

1

1159 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 7.56 (d, J ¼ 8:2 Hz,

2H), 7.30–7.15 (m, 5H), 7.10–6.93 (m, 7H), 6.37 (d, J ¼ 9:2

Hz, 1H), 5.35 (d, J ¼ 5:0 Hz, 1H), 4.90 (t, J ¼ 9:6 Hz, 1H),

4.06 (d, J ¼ 7:6 Hz, 1H), 3.37 (dd, J ¼ 9:9, 2.8 Hz, 1H), 2.31

(s, 3H), 1.35 (s, 3H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 209.3,

143.3, 141.4, 138.2, 136.8, 129.2, 128.4, 128.2, 127.6, 127.1,

127.1, 126.8, 125.1, 70.8, 64.0, 56.9, 32.8, 21.5. HRMS (ESI)

Y. Ogawa et al.

Bull. Chem. Soc. Jpn., 78, No. 7 (2005) 1321

(140 mg, 85%). Colorless oil. IR (neat) 1691, 1319, 1155 cm^ꢁ1

calcd for C₂₄H₂₆NO₄S ½M þ Hꢃ^þ424.1583, found 424.1603.

anti,anti-9a: Colorless oil. IR (neat) 3492, 3282, 1706, 1328,

.

1157 cm^ꢁ^{1 1}H NMR (270 MHz, CDCl₃) ꢁ 7.50–7.31 (m, 7H),

.

¹H NMR (270 MHz, CDCl₃) ꢁ 8.02 (d, J ¼ 8:0 Hz, 2H), 7.67

(t, J ¼ 7:6 Hz, 1H), 7.54 (t, J ¼ 7:6 Hz, 2H), 4.13 (d, J ¼ 4:1

Hz, 1H), 3.25 (dq, J ¼ 4:1, 5.9 Hz, 1H), 3.13 (s, 3H), 1.80 (d, J ¼

5:9 Hz, 3H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 191.2, 135.3, 134.1,

128.8, 128.3, 47.2, 45.1, 42.5, 13.9. HRMS (ESI) calcd for

C₁₁H₁₄NO₃S ½M þ Hꢃ^þ240.0694, found 240.0705.

7.10–6.93 (m, 5H), 6.78 (d, J ¼ 7:6 Hz, 2H), 6.51 (d, J ¼ 9:5

Hz, 1H), 4.93 (d, J ¼ 8:1 Hz, 1H), 4.39 (dd, J ¼ 9:2, 5.1 Hz,

1H), 3.24 (dd, J ¼ 8:1, 5.1 Hz, 1H), 2.70 (brs, 1H), 2.28 (s,

3H), 1.84 (s, 3H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 213.6, 142.6,

141.0, 138.1, 137.8, 128.9, 128.7, 128.4, 128.3, 127.2, 126.7,

126.3, 126.1, 74.1, 63.4, 57.3, 35.1, 21.4. HRMS (ESI) calcd for

C₂₄H₂₆NO₄S ½M þ Hꢃ^þ424.1583, found 424.1606.

trans-2-Benzoyl-3-methyl-1-(2,4,6-trimethylbenzenesulfonyl)-

aziridine (11). To a solution of 2-benzoyl-3-methyl-1H-aziridine

(250 mg, 1.55 mmol) and Et₃N (470 mg, 4.65 mmol) in CH₂Cl₂(3

mL) was added 2,4,6-trimethylbenzenesulfonyl chloride (MtsCl)

(508 mg, 2.33 mmol) at 0 ^ꢂC. After the reaction mixture was stir-

syn,anti-9b: Colorless oil. IR (neat) 3506, 3270, 1702, 1307,

1

1158 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 7.49 (d, J ¼ 8:2 Hz,

ꢂ

2H), 7.26–7.04 (m, 10H), 6.91 (d, J ¼ 8:2 Hz, 2H), 6.02 (d, J ¼

9:2 Hz, 1H), 4.93 (t, J ¼ 8:1 Hz, 1H), 3.92–3.86 (m, 1H), 3.52 (d,

J ¼ 9:1 Hz, 1H), 2.85–2.70 (m, 2H), 2.57–2.44 (m, 1H), 2.33 (s,

3H), 1.99 (s, 3H), 1.91–1.75 (m, 1H), 1.71–1.56 (m, 1H).

¹³C NMR (68 MHz, CDCl₃) ꢁ 209.3, 143.2, 141.2, 137.9, 137.1,

129.2, 128.5, 128.3, 128.2, 127.7, 127.0, 126.5, 125.8, 69.2,

61.2, 57.4, 37.4, 32.6, 30.8, 21.5. HRMS (ESI) calcd for

C₂₆H₃₀NO₄S ½M þ Hꢃ^þ452.1896, found 452.1898.

red for 1 h at 0 C, the reaction mixture was quenched with satu-

rated aqueous ammonium chloride and was diluted with ethyl ace-

tate. It was extracted with ethyl acetate, and the organic layer was

washed with brine and dried over anhydrous sodium sulfate. After

evaporation of the solvent under reduced pressure, the crude prod-

uct was puriﬁed by column chromatography to aﬀord trans-2-ben-

zoyl-3-methyl-1-(2,4,6-trimethylbenzenesulfonyl)aziridine (11)

(335 mg, 63%). Colorless oil. IR (neat) 1690, 1324, 1159 cm^ꢁ1

.

anti,anti-9b: Colorless oil. IR (neat) 3503, 3250, 1687, 1327,

¹H NMR (270 MHz, CDCl₃) ꢁ 7.93 (d, J ¼ 8:0 Hz, 2H), 7.58

(t, J ¼ 7:6 Hz, 1H), 7.44 (t, J ¼ 7:6 Hz, 2H), 6.91 (s, 2H), 4.13

(d, J ¼ 4:0 Hz, 1H), 3.24 (dq, J ¼ 4:0, 5.9 Hz, 1H), 2.65 (s,

6H), 2.26 (s, 3H), 1.80 (d, J ¼ 5:9 Hz, 3H). ¹³C NMR (68 MHz,

CDCl₃) ꢁ 191.8, 142.8, 139.6, 135.5, 134.0, 133.8, 131.7, 128.6,

128.3, 46.8, 45.1, 23.0, 21.0, 14.1. HRMS (ESI) calcd for

C₁₉H₂₂NO₃S ½M þ Hꢃ^þ344.1320, found 344.1317.

1

1156 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 7.42 (d, J ¼ 8:2 Hz,

2H), 7.30–6.88 (m, 12H), 6.35 (d, J ¼ 9:9 Hz, 1H), 4.76 (dd,

J ¼ 9:7, 6.8 Hz, 1H), 3.78–3.53 (m, 1H), 2.98 (t, J ¼ 6:8 Hz,

1H), 2.80–2.71 (m, 1H), 2.63–2.52 (m, 1H), 2.45 (d, J ¼ 6:8

Hz, 1H), 2.27 (s, 3H), 2.04 (s, 3H), 2.05–1.86 (m, 1H), 1.78–

1.69 (m, 1H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 213.7, 142.8,

141.1, 138.0, 137.3, 129.0, 128.4, 128.3, 128.3, 127.3, 126.8,

126.2, 125.9, 71.0, 62.0, 57.3, 36.8, 34.4, 31.8, 21.4. HRMS

(ESI) calcd for C₂₆H₃₀NO₄S ½M þ Hꢃ^þ452.1896, found

452.1908.

trans-1-Acetyl-2-benzoyl-3-methylaziridine (12). To a solu-

tion of 2-benzoyl-3-methyl-1H-aziridine (184 mg, 1.14 mmol) and

Et₃N (346 mg, 3.42 mmol) in CH₂Cl₂(3 mL) was added Ac₂O

(174 mg, 1.71 mmol) at 0 ^ꢂC. After the reaction mixture was stir-

ꢂ

syn,anti-9c: Colorless oil. IR (neat) 3472, 3242, 1709, 1306,

1

red for 1 h at 0 C, the reaction mixture was quenched with satu-

1154 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 7.49 (d, J ¼ 8:2 Hz,

rated aqueous ammonium chloride and was diluted with ethyl ace-

tate. It was extracted with ethyl acetate, and the organic layer was

washed with brine and dried over anhydrous sodium sulfate. After

evaporation of the solvent under reduced pressure, the crude prod-

uct was puriﬁed by column chromatography to aﬀord trans-1-ace-

tyl-2-benzoyl-3-methylaziridine (12) (230 mg, 99%). Colorless

2H), 7.14–6.94 (m, 7H), 6.14 (d, J ¼ 9:4 Hz, 1H), 5.00 (dd,

J ¼ 9:0, 7.4 Hz, 1H), 3.46 (d, J ¼ 9:6 Hz, 1H), 3.29 (t, J ¼ 9:4

Hz, 1H), 3.01 (d, J ¼ 7:1 Hz, 1H), 2.33 (s, 3H), 2.07 (s, 3H),

1.73–1.58 (m, 1H), 0.92 (d, J ¼ 6:6 Hz, 3H), 0.69 (d, J ¼ 6:6

Hz, 3H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 209.9, 143.0, 138.0,

137.3, 129.2, 128.4, 127.5, 126.9, 126.5, 75.6, 58.5, 57.5, 32.7,

30.8, 21.5, 19.8, 19.5. HRMS (ESI) calcd for C₂₁H₂₇NNaO₄S

½M þ Naꢃ^þ412.1559, found 412.1547.

oil. IR (neat) 1701, 1231 cm^ꢁ^{1 1}H NMR (270 MHz, CDCl₃) ꢁ

.

8.02 (d, J ¼ 8:0 Hz, 2H), 7.64 (t, J ¼ 7:6 Hz, 1H), 7.52 (t, J ¼

7:6 Hz, 2H), 3.87 (d, J ¼ 2:5 Hz, 1H), 3.24 (dq, J ¼ 2:5, 5.6

Hz, 1H), 2.15 (s, 3H), 1.48 (d, J ¼ 5:6 Hz, 3H). ¹³C NMR (68

MHz, CDCl₃) ꢁ 193.1, 180.2, 136.0, 133.8, 128.7, 128.3, 44.8,

41.8, 24.5, 17.3. HRMS (ESI) calcd for C₁₂H₁₃NNaO₂½M þ

Naꢃ^þ226.0844, found 226.0826.

anti,anti-9c: Colorless oil. IR (neat) 3512, 3272, 1698, 1329,

1

1160 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 7.43 (d, J ¼ 8:2 Hz,

2H), 7.09–6.92 (m, 7H), 6.43 (d, J ¼ 9:6 Hz, 1H), 4.71 (dd,

J ¼ 9:6, 6.4 Hz, 1H), 3.50–3.42 (m, 1H), 3.12 (t, J ¼ 6:6 Hz,

1H), 2.35 (d, J ¼ 6:4 Hz, 1H), 2.29 (s, 3H), 1.96 (s, 3H), 1.82–

1.71 (m, 1H), 0.91 (d, J ¼ 6:8 Hz, 3H), 0.87 (d, J ¼ 6:8 Hz,

3H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 214.2, 142.7, 138.4, 137.5,

128.9, 128.3, 127.2, 126.8, 126.1, 75.7, 59.1, 57.2, 34.5, 30.2,

21.4, 19.5, 16.0. HRMS (ESI) calcd for C₂₁H₂₇NNaO₄S ½M þ

Naꢃ^þ412.1559, found 412.1562.

trans-1,2-Dibenzoyl-3-methylaziridine (13). To a solution of

2-benzoyl-3-methyl-1H-aziridine (232 mg, 1.44 mmol) and Et₃N

(437 mg, 4.32 mmol) in CH₂Cl₂(5 mL) was added benzoyl chlo-

ride (303 mg, 2.16 mmol) at 0 ^ꢂC. After the reaction mixture was

stirred for 1 h at 0 ^ꢂC, the reaction mixture was quenched with sat-

urated aqueous ammonium chloride and was diluted with ethyl

acetate. It was extracted with ethyl acetate, and the organic layer

was washed with brine and dried over anhydrous sodium sulfate.

After evaporation of the solvent under reduced pressure, the crude

product was puriﬁed by column chromatography to aﬀord trans-

1,2-dibenzoyl-3-methylaziridine (13) (332 mg, 87%). Colorless

trans-2-Benzoyl-1-mesyl-3-methylaziridine (10). To a solu-

tion of 2-benzoyl-3-methyl-1H-aziridine (190 mg, 1.18 mmol) and

DMAP (288 mg, 2.36 mmol) in CH₂Cl₂(4 mL) was added mesyl

ꢂ

chloride (MsCl) (203 mg, 1.77 mmol) at 0 C. After the reaction

mixture was stirred for 1 h at 0 ^ꢂC, the reaction mixture was

quenched with saturated aqueous ammonium chloride and was di-

luted with ethyl acetate. It was extracted with ethyl acetate, and

the organic layer was washed with brine and dried over anhydrous

sodium sulfate. After evaporation of the solvent under reduced

pressure, the crude product was puriﬁed by column chromatogra-

phy to aﬀord trans-2-benzoyl-1-mesyl-3-methylaziridine (10)

oil. IR (neat) 1686, 1672, 1228 cm^ꢁ^{1 1}H NMR (270 MHz,

.

CDCl₃) ꢁ 8.04 (d, J ¼ 8:0 Hz, 2H), 8.01 (d, J ¼ 7:6 Hz, 2H),

7.62–7.37 (m, 6H), 4.05 (d, J ¼ 2:6 Hz, 1H), 3.20 (dq, J ¼ 2:6,

5.6 Hz, 1H), 1.44 (d, J ¼ 5:6 Hz, 3H). ¹³C NMR (68 MHz,

CDCl₃) ꢁ 193.1, 176.5, 136.1, 133.6, 132.4, 128.6, 128.4, 128.3,

128.3, 45.1, 42.3, 16.8. HRMS (ESI) calcd for C₁₇H₁₆NO₂½M þ

1322 Bull. Chem. Soc. Jpn., 78, No. 7 (2005)

SmI₂-Mediated Aldol Reactions of Acylaziridines

Hꢃ^þ266.1181, found 266.1173.

Reaction of Aziridinyl Ketone with Aldehyde. (Table 4, Entry

1). To a mixture of trans-2-benzoyl-3-methyl-1-mesylaziridine

(10) (42.1 mg, 0.176 mmol) and 3-phenylpropanal (23.6 mg,

0.194 mmol) in THF (4 mL) at ꢁ78 ^ꢂC under an argon atmo-

sphere was added a solution of SmI₂in THF (0.1 M, 4.4 mL,

0.44 mmol). After the reaction mixture was stirred for 1 h at

trans-2-Benzoyl-1-(1,1-dimethylethoxycarbonyl)-3-methyl-

aziridine (14). To a solution of 2-benzoyl-3-methyl-1H-aziridine

(300 mg, 1.86 mmol) and DMAP (454 mg, 3.72 mmol) in CH₃CN

(5 mL) was added Boc₂O (487 mg, 2.23 mmol) at 0 ^ꢂC. After the

ꢂ

reaction mixture was stirred for 1 h at 0 C, the reaction mixture

ꢂ

was quenched with saturated aqueous ammonium chloride and

was diluted with ethyl acetate. It was extracted with ethyl acetate,

and the organic layer was washed with brine and dried over anhy-

drous sodium sulfate. After evaporation of the solvent under re-

duced pressure, the crude product was puriﬁed by column chroma-

tography to aﬀord trans-2-benzoyl-1-(1,1-dimethylethoxycarbon-

yl)-3-methylaziridine (14) (312 mg, 64%). Colorless oil. IR (neat)

ꢁ78 C, the reaction mixture was quenched with saturated aque-

ous ammonium chloride and was diluted with ethyl acetate. It was

extracted with ethyl acetate, and the organic layer was washed

with brine and dried over anhydrous sodium sulfate. After evapo-

ration of the solvent under reduced pressure, the crude product

was puriﬁed by thin-layer chromatography to aﬀord syn,anti-10a

(18.3 mg, 28%) and anti,anti-10a (44.9 mg, 68%), respectively.

syn,anti-10a: Colorless oil. IR (neat) 3495, 3278, 1666, 1322,

1

1726, 1680, 1159 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 8.03 (d,

1

J ¼ 8:0 Hz, 2H), 7.61 (t, J ¼ 7:6 Hz, 1H), 7.50 (t, J ¼ 7:6 Hz,

2H), 3.71 (d, J ¼ 2:6 Hz, 1H), 2.96 (dq, J ¼ 2:6, 5.4 Hz, 1H),

1.43 (s, 9H), 1.41 (d, J ¼ 5:4 Hz, 3H). ¹³C NMR (68 MHz,

CDCl₃) ꢁ 193.2, 159.2, 136.5, 133.4, 128.5, 128.1, 81.3, 44.2,

41.2, 27.8, 16.7. HRMS (ESI) calcd for C₁₅H₂₀NO₃½M þ Hꢃ^þ

262.1443, found 262.1458.

trans-2-Benzoyl-1-(benzyloxycarbonyl)-3-methylaziridine

(15). To a solution of 2-benzoyl-3-methyl-1H-aziridine (256 mg,

1.59 mmol) and Na₂CO₃(253 mg, 2.39 mmol) in THF–H₂O (6

1135 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 7.91 (d, J ¼ 8:2 Hz,

2H), 7.63 (t, J ¼ 8:2 Hz, 1H), 7.49 (d, J ¼ 7:6 Hz, 2H), 7.25–

7.05 (m, 5H), 5.08 (d, J ¼ 9:2 Hz, 1H), 4.13–4.02 (m, 2H), 3.57

(d, J ¼ 10:2 Hz, 1H), 3.53 (dd, J ¼ 7:6, 2.4 Hz, 1H), 2.90 (s,

3H), 2.87–2.77 (m, 1H), 2.72–2.58 (m, 1H), 1.78–1.60 (m, 2H),

1.30 (d, J ¼ 6:8 Hz, 3H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 203.7,

141.2, 137.0, 134.2, 129.0, 128.9, 128.4, 128.3, 125.9, 70.0,

54.0, 50.6, 41.6, 38.0, 32.5, 22.2. HRMS (ESI) calcd for

C₂₀H₂₆NO₄S ½M þ Hꢃ^þ376.1583, found 376.1595.

ꢂ

mL, 1:1) was added CbzCl (325 mg, 1.91 mmol) at 0 C. After

ꢂ

anti,anti-10a: Colorless oil. IR (neat) 3466, 3291, 1651, 1319,

1

the reaction mixture was stirred for 1 h at 0 C, the reaction mix-

1162 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 7.93 (d, J ¼ 8:2 Hz,

ture was quenched with saturated aqueous ammonium chloride

and was diluted with ethyl acetate. It was extracted with ethyl ace-

tate, and the organic layer was washed with brine and dried over

anhydrous sodium sulfate. After evaporation of the solvent under

reduced pressure, the crude product was puriﬁed by column chro-

matography to aﬀord trans-2-benzoyl-1-(benzyloxycarbonyl)-3-

methylaziridine (15) (446 mg, 95%). Colorless oil. IR (neat)

2H), 7.61 (t, J ¼ 7:4 Hz, 1H), 7.48 (t, J ¼ 7:7 Hz, 2H), 7.27–

7.09 (m, 5H), 5.20 (d, J ¼ 9:7 Hz, 1H), 4.09–3.97 (m, 2H), 3.66

(dd, J ¼ 6:8, 5.4 Hz, 1H), 2.88 (d, J ¼ 8:1 Hz, 1H), 2.85–2.77

(m, 1H), 2.79 (s, 3H), 2.72–2.59 (m, 1H), 1.86–1.66 (m, 2H),

1.31 (d, J ¼ 6:6 Hz, 3H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 205.4,

141.2, 138.0, 134.0, 128.9, 128.4, 128.3, 128.3, 125.9, 71.2,

54.6, 50.7, 41.6, 37.7, 32.2, 21.5. HRMS (ESI) calcd for

C₂₀H₂₆NO₄S ½M þ Hꢃ^þ376.1583, found 376.1613.

1729, 1677, 1302, 1197 cm^ꢁ^{1 1}H NMR (270 MHz, CDCl₃) ꢁ

.

7.92 (d, J ¼ 8:0 Hz, 2H), 7.51 (t, J ¼ 7:6 Hz, 1H), 7.41 (t, J ¼

7:6 Hz, 2H), 7.37–7.08 (m, 5H), 5.14 (d, J ¼ 12:2 Hz, 1H),

5.06 (d, J ¼ 12:2 Hz, 1H), 3.72 (d, J ¼ 2:0 Hz, 1H), 2.90 (dq,

J ¼ 2:0, 5.4 Hz, 1H), 1.35 (d, J ¼ 5:4 Hz, 3H). ¹³C NMR (68

MHz, CDCl₃) ꢁ 193.0, 160.6, 136.2, 135.4, 133.6, 128.6, 128.4,

128.2, 128.2, 128.0, 68.2, 44.4, 42.0, 16.9. HRMS (ESI) calcd

for C₁₈H₁₈NO₃½M þ Hꢃ^þ296.1287, found 296.1311.

syn,anti-11a: Colorless oil. IR (neat) 3493, 3291, 1668, 1324,

1

1157 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 7.63 (d, J ¼ 8:2 Hz,

2H), 7.53 (t, J ¼ 8:2 Hz, 1H), 7.36 (t, J ¼ 7:9 Hz, 2H), 7.25–

7.05 (m, 5H), 6.80 (s, 2H), 5.57 (d, J ¼ 9:1 Hz, 1H), 4.13–4.05

(m, 1H), 3.95–3.83 (m, 1H), 3.71 (brd, J ¼ 8:6 Hz, 1H), 3.44

(dd, J ¼ 5:9, 2.6 Hz, 1H), 2.87–2.75 (m, 1H), 2.66–2.53 (m,

1H), 2.48 (s, 6H), 2.25 (s, 3H), 1.82–1.75 (m, 1H), 1.68–1.60

(m, 1H), 1.17 (d, J ¼ 6:6 Hz, 3H). ¹³C NMR (68 MHz, CDCl₃)

ꢁ 202.5, 141.7, 141.3, 138.5, 136.5, 134.6, 133.6, 131.8, 128.6,

128.3, 128.3, 128.1, 125.8, 70.3, 53.8, 50.7, 37.9, 32.6, 23.0,

21.1, 21.0. HRMS (ESI) calcd for C₂₈H₃₃KNO₄S ½M þ Kꢃ^þ

518.1767, found 518.1764.

trans-2-Benzoyl-1-(9-ﬂuorenylmethoxycarbonyl)-3-methyl-

aziridine (16). To a solution of 2-benzoyl-3-methyl-1H-aziridine

(180 mg, 1.12 mmol) and Na₂CO₃(178 mg, 1.68 mmol) in THF–

H₂O (4 mL, 1:1) was added FmocCl (348 mg, 1.34 mmol) at 0 ^ꢂC.

After the reaction mixture was stirred for 1 h at 0 ^ꢂC, the reaction

mixture was quenched with saturated aqueous ammonium chlo-

ride and was diluted with ethyl acetate. It was extracted with ethyl

acetate, and the organic layer was washed with brine and dried

over anhydrous sodium sulfate. After evaporation of the solvent

under reduced pressure, the crude product was puriﬁed by column

chromatography to aﬀord trans-2-benzoyl-1-(9-ﬂuorenylmethoxy-

carbonyl)-3-methylaziridine (16) (421 mg, 98%). Colorless oil. IR

(neat) 1727, 1677, 1303, 1202 cm^ꢁ1. ¹H NMR (270 MHz, CDCl₃)

ꢁ 7.97 (d, J ¼ 8:0 Hz, 2H), 7.74–7.45 (m, 7H), 7.38–7.30 (m, 2H),

7.26–7.14 (m, 2H), 4.56 (dd, J ¼ 10:5, 6.8 Hz, 1H), 4.40 (dd,

J ¼ 10:5, 6.9 Hz, 1H), 4.23 (t, J ¼ 6:9 Hz, 1H), 3.78 (d, J ¼

2:8 Hz, 1H), 2.97 (dq, J ¼ 2:8, 5.4 Hz, 1H), 1.39 (d, J ¼ 5:4

Hz, 3H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 193.0, 160.6, 143.6,

143.5, 141.1, 136.2, 133.8, 128.7, 128.3, 127.5, 126.9, 125.1,

124.9, 119.8, 68.2, 46.9, 44.4, 42.2, 16.9. HRMS (ESI) calcd for

C₂₅H₂₂NO₃½M þ Hꢃ^þ384.1600, found 384.1632.

anti,anti-11a: Colorless oil. IR (neat) 3493, 3341, 1660, 1328,

1

1156 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 7.84 (d, J ¼ 8:2 Hz,

2H), 7.55 (t, J ¼ 7:4 Hz, 1H), 7.44 (t, J ¼ 7:9 Hz, 2H), 7.27–

7.07 (m, 5H), 6.89 (s, 2H), 5.69 (d, J ¼ 9:4 Hz, 1H), 4.10–3.99

(m, 1H), 3.89–3.79 (m, 1H), 3.63 (t, J ¼ 5:6 Hz, 1H), 2.82–2.69

(m, 1H), 2.59 (s, 6H), 2.58–2.44 (m, 1H), 2.26 (s, 3H), 1.77–

1.64 (m, 2H), 1.05 (d, J ¼ 6:8 Hz, 3H). ¹³C NMR (68 MHz,

CDCl₃) ꢁ 204.9, 141.8, 141.3, 138.4, 137.9, 135.1, 133.7, 131.8,

128.7, 128.4, 128.3, 128.2, 125.8, 71.5, 54.6, 50.1, 37.2, 31.9,

23.0, 21.0, 20.5. HRMS (ESI) calcd for C₂₈H₃₃KNO₄S ½M þ

Kꢃ^þ518.1767, found 518.1764.

syn,anti-12a: Colorless oil. IR (neat) 3302, 1667, 1373, 1213

cm^ꢁ1

.

¹H NMR (270 MHz, CDCl₃) ꢁ 7.88 (d, J ¼ 8:2 Hz, 2H),

7.58 (t, J ¼ 7:4 Hz, 1H), 7.49–7.09 (m, 7H), 6.22 (d, J ¼ 8:3

Hz, 1H), 4.51–4.40 (m, 1H), 4.08–3.90 (m, 2H), 3.61 (dd,

J ¼ 6:1, 2.1 Hz, 1H), 2.84–2.77 (m, 1H), 2.73–2.64 (m, 1H),

1.89 (s, 3H), 1.85–1.69 (m, 2H), 1.26 (d, J ¼ 6:6 Hz, 3H).

Typical Procedure for Samarium(II) Iodide-Mediated Aldol

Y. Ogawa et al.

Bull. Chem. Soc. Jpn., 78, No. 7 (2005) 1323

¹³C NMR (68 MHz, CDCl₃) ꢁ 203.3, 169.8, 141.3, 137.3, 133.6,

128.7, 128.3, 128.2, 128.1, 125.7, 70.1, 53.1, 46.5, 37.8, 32.4,

23.3, 19.3. HRMS (ESI) calcd for C₂₁H₂₅KNO₃½M þ Kꢃ^þ

378.1472, found 378.1460.

(ESI) calcd for C₃₄H₃₄NO₄½M þ Hꢃ^þ520.2488, found 520.2504.

trans-2-Benzoyl-1-(9-ﬂuorenylmethoxycarbonyl)-3-propyl-

aziridine (17). Fmoc-aziridines were prepared by the same pro-

cedure for 16. Colorless oil. IR (neat) 1732, 1672, 1305, 1201

anti,anti-12a: Colorless oil. IR (neat) 3400, 3311, 1658, 1374

.

cm^ꢁ1

.

¹H NMR (270 MHz, CDCl₃) ꢁ 7.96 (d, J ¼ 8:0 Hz, 2H),

cm^ꢁ1

¹H NMR (270 MHz, CDCl₃) ꢁ 7.98 (d, J ¼ 8:2 Hz, 2H),

7.71–7.42 (m, 7H), 7.36–7.27 (m, 2H), 7.26–7.11 (m, 2H), 4.54

(dd, J ¼ 10:6, 6.8 Hz, 1H), 4.41 (dd, J ¼ 10:8, 6.9 Hz, 1H),

4.23 (t, J ¼ 6:9 Hz, 1H), 3.83 (d, J ¼ 2:6 Hz, 1H), 2.91–2.85

(m, 1H), 1.62–1.49 (m, 4H), 0.97 (t, J ¼ 7:1 Hz, 3H). ¹³C NMR

(68 MHz, CDCl₃) ꢁ 193.0, 160.6, 143.6, 143.5, 141.0, 136.1,

133.7, 128.6, 128.2, 127.4, 126.8, 126.7, 125.0, 124.8, 119.7,

68.1, 46.9, 46.7, 43.4, 33.5, 20.1, 13.7. HRMS (ESI) calcd for

C₂₇H₂₅NNaO₃½M þ Naꢃ^þ434.1732, found 434.1710.

7.59 (t, J ¼ 7:4 Hz, 1H), 7.48 (t, J ¼ 7:7 Hz, 2H), 7.28–7.11

(m, 5H), 6.49 (d, J ¼ 8:6 Hz, 1H), 4.46–4.41 (m, 1H), 4.00–

3.80 (m, 1H), 3.84 (dd, J ¼ 7:2, 4.5 Hz, 1H), 2.90–2.77 (m,

1H), 2.72–2.62 (m, 1H), 2.63 (d, J ¼ 7:3 Hz, 1H), 2.00–1.67

(m, 2H), 1.91 (s, 3H), 1.12 (d, J ¼ 6:8 Hz, 3H). ¹³C NMR (68

MHz, CDCl₃) ꢁ 205.9, 169.4, 141.1, 138.2, 133.7, 128.7, 128.4,

128.3, 128.3, 125.8, 71.2, 53.7, 45.2, 36.6, 31.6, 23.5, 19.7. HRMS

(ESI) calcd for C₂₁H₂₆NO₃½M þ Hꢃ^þ340.1913, found 340.1900.

trans-2-Benzoyl-1-(9-ﬂuorenylmethoxycarbonyl)-3-isopro-

pylaziridine (18). Colorless oil. IR (neat) 1727, 1203 cm^ꢁ1

.

syn,anti-13a: Colorless oil. IR (neat) 3326, 1663, 1542 cm^ꢁ1

.

¹H NMR (270 MHz, CDCl₃) ꢁ 7.87 (d, J ¼ 8:2 Hz, 2H), 7.67 (d,

J ¼ 7:4 Hz, 2H), 7.63–7.38 (m, 7H), 7.29–7.02 (m, 4H), 4.74–

4.65 (m, 1H), 4.23–4.10 (m, 2H), 3.71 (dd, J ¼ 5:6, 2.1 Hz,

1H), 2.90–2.80 (m, 1H), 2.73–2.65 (m, 1H), 1.96–1.65 (m, 2H),

1.40 (d, J ¼ 6:9 Hz, 3H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 203.7,

166.9, 141.3, 137.1, 134.1, 133.8, 131.4, 128.9, 128.4, 128.3,

128.3, 128.3, 126.8, 125.8, 70.5, 52.8, 47.1, 38.2, 32.6, 19.6.

HRMS (ESI) calcd for C₂₆H₂₈NO₃½M þ Hꢃ^þ402.2069, found

402.2068.

¹H NMR (270 MHz, CDCl₃) ꢁ 7.96 (d, J ¼ 8:0 Hz, 2H), 7.71–

7.42 (m, 7H), 7.35–7.27 (m, 2H), 7.22–7.11 (m, 2H), 4.53 (dd,

J ¼ 10:6, 6.9 Hz, 1H), 4.42 (dd, J ¼ 10:3, 7.0 Hz, 1H), 4.24 (t,

J ¼ 6:9 Hz, 1H), 3.92 (d, J ¼ 2:6 Hz, 1H), 2.73 (dd, J ¼ 7:3,

2.6 Hz, 1H), 1.74–1.58 (m, 1H), 1.09 (d, J ¼ 6:8 Hz, 3H), 1.01

(d, J ¼ 6:9 Hz, 3H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 192.9,

160.6, 143.7, 143.5, 141.0, 136.1, 133.7, 128.6, 128.1, 127.4,

127.4, 126.8, 126.8, 125.0, 124.8, 119.6, 68.2, 52.9, 46.8, 42.3,

30.5, 19.6, 19.2. HRMS (ESI) calcd for C₂₇H₂₅NNaO₃½M þ

Naꢃ^þ434.1732, found 434.1741.

anti,anti-13a: Colorless oil. IR (neat) 3480, 3354, 1650, 1524

.

cm^ꢁ1

¹H NMR (270 MHz, CDCl₃) ꢁ 8.02 (d, J ¼ 8:2 Hz, 2H),

trans-2-Benzoyl-1-(9-ﬂuorenylmethoxycarbonyl)-3-phenyl-

7.74 (d, J ¼ 7:4 Hz, 2H), 7.63–7.25 (m, 7H), 7.09–7.02 (m,

4H), 4.69–4.62 (m, 1H), 4.10–3.98 (m, 1H), 3.93 (dd, J ¼ 7:6,

4.1 Hz, 1H), 2.83–2.76 (m, 1H), 2.70–2.62 (m, 2H), 2.05–1.82

(m, 2H), 1.21 (d, J ¼ 6:9 Hz, 3H). ¹³C NMR (68 MHz, CDCl₃)

ꢁ 206.2, 166.5, 140.9, 138.3, 134.1, 133.7, 131.4, 128.8, 128.5,

128.4, 128.3, 128.2, 126.8, 125.7, 71.5, 54.0, 45.5, 36.4, 31.5,

19.9. HRMS (ESI) calcd for C₂₆H₂₈NO₃½M þ Hꢃ^þ402.2069,

found 402.2056.

aziridine (19). Colorless oil. IR (neat) 1732, 1677, 1217 cm^ꢁ1

.

¹H NMR (270 MHz, CDCl₃) ꢁ 7.95 (d, J ¼ 8:0 Hz, 2H), 7.67–

7.07 (m, 16H), 4.55 (dd, J ¼ 10:4, 7.1 Hz, 1H), 4.41 (dd,

J ¼ 10:4, 7.4 Hz, 1H), 4.25 (t, J ¼ 7:1 Hz, 1H), 4.11 (d, J ¼

2:5 Hz, 1H), 3.96 (d, J ¼ 2:5 Hz, 1H). ¹³C NMR (68 MHz,

CDCl₃) ꢁ 191.7, 160.1, 143.6, 143.4, 141.0, 136.0, 135.4, 133.9,

128.7, 128.5, 128.4, 128.3, 127.5, 127.4, 126.8, 126.8, 126.3,

125.1, 125.0, 119.7, 68.6, 47.6, 47.1, 46.8. HRMS (ESI) calcd

for C₃₀H₂₃NNaO₃½M þ Naꢃ^þ468.1576, found 468.1605.

anti,anti-14a: Colorless oil. IR (neat) 3508, 3385, 1688, 1521

.

cm^ꢁ1

¹H NMR (270 MHz, CDCl₃) ꢁ 7.97 (d, J ¼ 8:2 Hz, 2H),

Typical Procedure for Samarium(II) Iodide-Mediated Aldol

Reaction of Aziridinyl Ketone with Aldehyde. (Table 5, Entry

7.58 (t, J ¼ 7:4 Hz, 1H), 7.47 (t, J ¼ 7:7 Hz, 2H), 7.26–7.07

(m, 5H), 5.29 (d, J ¼ 8:7 Hz, 1H), 4.17–3.98 (m, 2H), 3.88 (t, J ¼

8:0 Hz, 1H), 2.90–2.77 (m, 1H), 2.88 (d, J ¼ 8:1 Hz, 1H), 2.71–

2.58 (m, 1H), 1.95–1.72 (m, 2H), 1.38 (s, 9H), 1.19 (d, J ¼ 6:9

Hz, 3H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 205.6, 155.1, 141.4,

138.2, 133.6, 128.7, 128.4, 128.3, 128.3, 125.7, 71.5, 53.9, 46.9,

37.3, 32.4, 32.2, 28.4, 19.7. HRMS (ESI) calcd for C₂₄H₃₁KNO₄

½M þ Kꢃ^þ436.1890, found 436.1867.

1).

To a mixture of trans-2-benzoyl-1-(9-ﬂuorenylmethoxy-

carbonyl)-3-methylaziridine (16) (57.5 mg, 0.150 mmol) and 3-

phenylpropanal (22.1 mg, 0.165 mmol) in THF (4 mL) at ꢁ78

^ꢂC under an argon atmosphere was added a solution of SmI₂in

THF (0.1 M, 3.8 mL, 0.38 mmol). After the reaction mixture

was stirred for 1 h at ꢁ78 ^ꢂC, the reaction mixture was quenched

with saturated aqueous ammonium chloride and was diluted with

ethyl acetate. It was extracted with ethyl acetate, and the organic

layer was washed with brine and dried over anhydrous sodium sul-

fate. After evaporation of the solvent under reduced pressure, the

crude product was puriﬁed by thin-layer chromatography to aﬀord

anti,anti-16a (73.2 mg, 94%).

anti,anti-15a: Colorless oil. IR (neat) 3411, 1700, 1507, 1238

cm^ꢁ1

.

¹H NMR (270 MHz, CDCl₃) ꢁ 7.97 (d, J ¼ 8:2 Hz, 2H),

7.57 (t, J ¼ 7:4 Hz, 1H), 7.47–7.06 (m, 12H), 5.63 (d, J ¼ 8:8

Hz, 1H), 5.04 (s, 2H), 4.34–4.13 (m, 1H), 4.10–3.98 (m, 1H),

3.85 (t, J ¼ 5:8 Hz, 1H), 2.88–2.75 (m, 2H), 2.68–2.55 (m, 1H),

1.90–1.68 (m, 2H), 1.17 (d, J ¼ 6:8 Hz, 3H). ¹³C NMR (68

MHz, CDCl₃) ꢁ 205.6, 155.6, 141.5, 138.1, 133.6, 128.7, 128.4,

128.3, 128.2, 128.0, 127.8, 125.7, 71.4, 66.6, 53.7, 47.4, 37.2,

32.0, 19.7. HRMS (ESI) calcd for C₂₇H₃₀NO₄½M þ Hꢃ^þ

432.2175, found 432.2214.

anti,anti-16b: Colorless oil. IR (neat) 3403, 1702, 1505, 1478,

1

1241 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 8.03 (d, J ¼ 8:2 Hz,

2H), 7.79–7.10 (m, 16H), 5.97 (d, J ¼ 8:7 Hz, 1H), 5.20–5.11

(m, 1H), 4.49–4.28 (m, 3H), 4.23–4.11 (m, 1H), 3.78–3.67 (m,

1H), 2.63 (d, J ¼ 1:8 Hz, 1H), 1.10 (d, J ¼ 6:6 Hz, 3H). ¹³C NMR

(68 MHz, CDCl₃) ꢁ 205.1, 155.3, 143.8, 141.2, 138.5, 133.3,

128.6, 128.5, 128.3, 128.1, 127.6, 127.0, 126.2, 125.6, 125.0,

119.0, 74.7, 66.6, 60.0, 55.8, 47.3, 21.1. HRMS (ESI) calcd for

C₃₂H₃₀NO₄½M þ Hꢃ^þ492.2175, found 492.2209.

anti,anti-16a: Colorless oil. IR (neat) 3412, 3335, 1687, 1536,

1448, 1257 cm^ꢁ1. ¹H NMR (270 MHz, CDCl₃) ꢁ 8.00 (d, J ¼ 8:2

Hz, 2H), 7.76–7.00 (m, 16H), 5.64 (d, J ¼ 8:4 Hz, 1H), 4.38–4.00

(m, 5H), 3.87 (t, J ¼ 5:6 Hz, 1H), 2.84–2.75 (m, 2H), 2.72–2.57

(m, 1H), 1.90–1.58 (m, 2H), 1.21 (d, J ¼ 6:8 Hz, 3H). ¹³C NMR

(68 MHz, CDCl₃) ꢁ 205.7, 155.6, 143.8, 141.3, 141.2, 138.1,

133.7, 128.7, 128.4, 128.3, 128.3, 127.6, 126.9, 125.8, 125.0,

119.9, 71.4, 66.8, 53.7, 47.5, 47.2, 37.3, 32.0, 19.7. HRMS

anti,anti-16c: Colorless oil. IR (neat) 3407, 1705, 1505, 1448,

1

1244 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 8.03 (d, J ¼ 8:2 Hz,

2H), 7.77–7.22 (m, 11H), 5.80 (d, J ¼ 8:6 Hz, 1H), 4.41–4.05

(m, 4H), 3.96 (t, J ¼ 5:4 Hz, 1H), 3.90–3.80 (m, 1H), 2.71 (d, J ¼

1324 Bull. Chem. Soc. Jpn., 78, No. 7 (2005)

SmI₂-Mediated Aldol Reactions of Acylaziridines

1

7:1 Hz, 1H), 1.85–1.75 (m, 1H), 1.21 (d, J ¼ 6:4 Hz, 3H), 0.97 (d,

J ¼ 6:6 Hz, 3H), 0.89 (d, J ¼ 6:6 Hz, 3H). ¹³C NMR (68 MHz,

CDCl₃) ꢁ 206.2, 155.6, 143.8, 141.1, 138.3, 133.6, 128.7, 128.4,

127.6, 126.9, 125.9, 119.8, 76.7, 66.7, 50.5, 47.4, 47.2, 31.2,

19.9, 19.7, 16.3. HRMS (ESI) calcd for C₂₉H₃₂NO₄½M þ Hꢃ^þ

458.2331, found 458.2338.

1248 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 7.87 (d, J ¼ 8:2 Hz,

2H), 7.75 (d, J ¼ 8:2 Hz, 2H), 7.63–7.25 (m, 9H), 5.98 (d, J ¼

10:2 Hz, 1H), 4.31–4.05 (m, 4H), 4.00–3.91 (m, 2H), 3.61 (t, J ¼

9:2 Hz, 1H), 2.05–1.92 (m, 1H), 1.88–1.75 (m, 1H), 1.09 (d, J ¼

6:6 Hz, 3H), 1.05 (d, J ¼ 6:4 Hz, 3H), 0.99 (d, J ¼ 6:6 Hz, 3H),

0.93 (d, J ¼ 6:8 Hz, 3H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 204.1,

156.1, 144.1, 143.8, 141.2, 141.1, 136.4, 133.7, 128.9, 128.0,

127.5, 126.9, 125.1, 125.1, 119.8, 119.8, 77.3, 66.7, 58.2, 47.3,

45.6, 33.7, 31.7, 20.2, 19.9, 19.8. HRMS (ESI) calcd for

C₃₁H₃₆NO₄½M þ Hꢃ^þ486.2644, found 486.2645.

syn,anti-17a: Colorless oil. IR (neat) 3358, 1686, 1534, 1449,

1

1226 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 7.88 (d, J ¼ 8:2 Hz,

2H), 7.78–7.06 (m, 16H), 5.40 (d, J ¼ 9:1 Hz, 1H), 4.43–4.25

(m, 2H), 4.19–3.95 (m, 3H), 3.88 (d, J ¼ 6:5 Hz, 1H), 3.75 (dd,

J ¼ 6:8, 2.1 Hz, 1H), 2.86–2.80 (m, 1H), 2.78–2.55 (m, 1H),

1.92–1.60 (m, 2H), 1.50–1.20 (m, 4H), 0.86 (t, J ¼ 7:3 Hz, 3H).

¹³C NMR (68 MHz, CDCl₃) ꢁ 204.0, 156.0, 143.9, 141.4, 141.2,

137.4, 133.7, 128.8, 128.3, 128.2, 127.6, 126.9, 125.8, 125.0,

125.0, 119.8, 70.5, 66.6, 52.2, 52.1, 47.3, 38.1, 35.6, 32.6, 19.8,

13.8. HRMS (ESI) calcd for C₃₆H₃₈NO₄½M þ Hꢃ^þ548.2801,

found 548.2819.

anti,anti-18b: Colorless oil. IR (neat) 3410, 1706, 1507, 1240

cm^ꢁ1

.

¹H NMR (270 MHz, CDCl₃) ꢁ 7.99 (d, J ¼ 7:3 Hz, 2H),

7.75 (d, J ¼ 7:3 Hz, 2H), 7.62–7.25 (m, 9H), 6.11 (d, J ¼ 10:0

Hz, 1H), 4.35 (d, J ¼ 6:9 Hz, 2H), 4.19 (t, J ¼ 7:0 Hz, 1H),

4.05 (dd, J ¼ 8:6, 4.6 Hz, 1H), 3.96–3.88 (m, 1H), 3.77–3.56

(m, 1H), 2.07–1.95 (m, 1H), 1.92 (d, J ¼ 5:6 Hz, 1H), 1.60–

1.50 (m, 1H), 1.00 (d, J ¼ 6:6 Hz, 3H), 0.93 (d, J ¼ 6:9 Hz,

3H), 0.87 (d, J ¼ 6:9 Hz, 3H), 0.84 (d, J ¼ 6:8 Hz, 3H). ¹³C NMR

(68 MHz, CDCl₃) ꢁ 206.5, 156.2, 143.9, 143.8, 141.2, 141.1,

139.0, 133.3, 128.6, 128.3, 127.5, 126.9, 125.0, 125.0, 119.8,

77.2, 66.7, 56.9, 47.8, 47.4, 32.1, 30.0, 20.2, 19.9, 19.1, 14.8.

HRMS (ESI) calcd for C₃₁H₃₆NO₄½M þ Hꢃ^þ486.2644, found

486.2636.

anti,anti-17a: Colorless oil. IR (neat) 3354, 1686, 1530, 1449,

1

1260 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 7.98 (d, J ¼ 8:2 Hz,

2H), 7.77–7.06 (m, 16H), 5.67 (d, J ¼ 9:4 Hz, 1H), 4.41–4.25

(m, 2H), 4.18–4.05 (m, 3H), 3.87 (t, J ¼ 5:9 Hz, 1H), 2.83–2.78

(m, 1H), 2.77–2.60 (m, 2H), 2.08–1.71 (m, 2H), 1.65–1.15 (m,

4H), 0.81 (t, J ¼ 7:3 Hz, 3H). ¹³C NMR (68 MHz, CDCl₃) ꢁ

205.7, 156.0, 143.8, 141.2, 141.1, 138.3, 133.6, 128.7, 128.4,

128.3, 127.5, 126.9, 125.8, 125.0, 125.0, 119.0, 71.6, 66.7, 53.2,

51.4, 47.3, 37.1, 36.1, 31.9, 19.6, 13.8. HRMS (ESI) calcd for

C₃₆H₃₈NO₄½M þ Hꢃ^þ548.2801, found 548.2801.

syn,anti-19a: Colorless oil. IR (neat) 3343, 1694, 1449, 1248

.

cm^ꢁ1

¹H NMR (270 MHz, CDCl₃) ꢁ 7.85 (d, J ¼ 8:2 Hz, 2H),

7.74 (d, J ¼ 8:2 Hz, 2H), 7.67–6.97 (m, 19H), 6.65 (d, J ¼ 8:9

Hz, 1H), 5.41–5.33 (m, 1H), 4.42–4.05 (m, 4H), 3.95–3.74 (m,

2H), 2.82–2.69 (m, 1H), 2.58–2.42 (m, 1H), 2.03–1.81 (m, 1H),

1.68–1.55 (m, 1H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 202.8, 156.0,

143.7, 141.2, 140.2, 138.4, 133.8, 128.9, 128.8, 128.3, 128.2,

128.1, 127.6, 127.5, 126.9, 126.3, 125.7, 125.0, 119.8, 70.5,

67.0, 56.1, 53.3, 47.2, 38.3, 32.6. HRMS (ESI) calcd for

C₃₉H₃₅KNO₄½M þ Kꢃ^þ620.2203, found 620.2197.

anti,anti-17b: Colorless oil. IR (neat) 3411, 1709, 1668, 1507,

1

1241 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 8.02 (d, J ¼ 8:2 Hz,

2H), 7.77–7.22 (m, 11H), 5.81 (d, J ¼ 8:6 Hz, 1H), 4.38–4.26

(m, 2H), 4.18 (t, J ¼ 6:9 Hz, 1H), 4.09–3.93 (m, 2H), 3.90–3.82

(m, 1H), 2.41 (d, J ¼ 6:6 Hz, 1H), 1.91–1.84 (m, 1H), 1.55–

1.20 (m, 4H), 0.97 (d, J ¼ 6:8 Hz, 3H), 0.90 (d, J ¼ 6:8 Hz,

3H), 0.81 (t, J ¼ 7:1 Hz, 3H). ¹³C NMR (68 MHz, CDCl₃) ꢁ

206.3, 156.0, 143.8, 141.1, 138.6, 133.5, 128.6, 128.4, 127.5,

126.9, 124.9, 119.0, 76.8, 66.6, 51.4, 49.9, 47.3, 36.2, 30.8, 19.8,

19.6, 15.8, 13.8. HRMS (ESI) calcd for C₃₁H₃₆NO₄½M þ Hꢃ^þ

486.2644, found 486.2647.

anti,anti-19a: Colorless oil. IR (neat) 3401, 1698, 1663, 1498,

1

1110 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 7.73 (d, J ¼ 8:2 Hz,

2H), 7.65 (d, J ¼ 8:2 Hz, 2H), 7.54–7.01 (m, 19H), 6.37 (d, J ¼

8:7 Hz, 1H), 5.31–5.24 (m, 1H), 4.33–4.20 (m, 3H), 4.12–4.00 (m,

2H), 2.95–2.80 (m, 1H), 2.70–2.40 (m, 2H), 1.91–1.32 (m, 2H).

¹³C NMR (68 MHz, CDCl₃) ꢁ 205.4, 155.4, 143.6, 141.1, 140.0,

138.4, 133.4, 128.6, 128.4, 128.4, 128.3, 128.1, 127.5, 126.9,

126.9, 126.1, 125.9, 125.0, 119.8, 77.2, 71.8, 67.0, 55.2, 47.2,

37.0, 31.8. HRMS (ESI) calcd for C₃₉H₃₆NO₄½M þ Hꢃ^þ

582.2644, found 582.2664.

syn,anti-18a: Colorless oil. IR (neat) 3343, 1687, 1535, 1248

.

cm^ꢁ1

¹H NMR (270 MHz, CDCl₃) ꢁ 7.85 (d, J ¼ 8:2 Hz, 2H),

7.76 (d, J ¼ 8:2 Hz, 2H), 7.61–7.08 (m, 14H), 5.55 (d, J ¼ 10:2

Hz, 1H), 4.37–4.25 (m, 2H), 4.17 (t, J ¼ 6:9 Hz, 1H), 4.11–3.97

(m, 3H), 3.67 (d, J ¼ 5:9 Hz, 1H), 2.86–2.78 (m, 1H), 2.71–

2.61 (m, 1H), 1.90–1.75 (m, 2H), 1.68–1.57 (m, 1H), 0.96 (d, J ¼

6:8 Hz, 3H), 0.91 (d, J ¼ 6:6 Hz, 3H). ¹³C NMR (68 MHz,

CDCl₃) ꢁ 203.2, 156.3, 143.9, 143.6, 141.2, 141.1, 136.8, 133.5,

128.7, 128.2, 128.0, 127.4, 126.8, 125.7, 124.9, 124.9, 119.7,

70.2, 66.6, 57.3, 49.9, 47.2, 38.2, 32.5, 31.0, 20.2, 18.5. HRMS

(ESI) calcd for C₃₆H₃₈NO₄½M þ Hꢃ^þ548.2801, found 548.2807.

anti,anti-18a: Colorless oil. IR (neat) 3411, 1718, 1666, 1506,

syn,anti-19b: Colorless oil. IR (neat) 3402, 1704, 1449, 1248

.

cm^ꢁ1

¹H NMR (270 MHz, CDCl₃) ꢁ 7.97 (d, J ¼ 8:2 Hz, 2H),

7.77–6.97 (m, 16H), 5.42 (d, J ¼ 8:9 Hz, 1H), 4.50–3.89 (m,

6H), 3.35 (t, J ¼ 9:6 Hz, 1H), 1.80–1.60 (m, 1H), 0.92 (d, J ¼

6:6 Hz, 3H), 0.69 (d, J ¼ 6:6 Hz, 3H). ¹³C NMR (68 MHz,

CDCl₃) ꢁ 203.3, 156.3, 143.7, 141.1, 136.2, 133.8, 133.2, 129.0,

128.8, 128.2, 127.5, 126.9, 126.1, 125.0, 119.8, 74.8, 66.9, 56.1,

52.5, 47.2, 32.3, 19.6, 15.5. HRMS (ESI) calcd for C₃₄H₃₄NO₄

½M þ Hꢃ^þ520.2488, found 520.2504.

1

1235 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 7.97 (d, J ¼ 7:3 Hz,

2H), 7.78–7.05 (m, 16H), 5.94 (d, J ¼ 10:0 Hz, 1H), 4.41–4.27

(m, 2H), 4.17 (t, J ¼ 6:9 Hz, 1H), 4.11–3.98 (m, 1H), 3.96–3.89

(m, 1H), 3.88–3.72 (m, 1H), 2.95–2.80 (m, 1H), 2.78–2.58 (m,

1H), 2.19 (d, J ¼ 6:3 Hz, 1H), 2.10–2.00 (m, 1H), 1.95–1.77

(m, 1H), 1.75–1.58 (m, 1H), 0.86 (d, J ¼ 6:8 Hz, 3H), 0.82 (d,

J ¼ 6:8 Hz, 3H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 205.7, 156.3,

143.8, 143.7, 141.2, 141.1, 138.6, 133.4, 128.7, 128.3, 128.3,

127.5, 127.0, 125.8, 125.1, 125.0, 119.9, 72.4, 66.8, 57.1, 51.0,

47.4, 36.8, 32.0, 31.7, 20.3, 19.1. HRMS (ESI) calcd for

C₃₆H₃₈NO₄½M þ Hꢃ^þ548.2801, found 548.2803.

anti,anti-19b: Colorless oil. IR (neat) 3401, 1703, 1664, 1502,

1

1245 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 7.78–7.11 (m, 18H),

6.59 (d, J ¼ 8:6 Hz, 1H), 5.20 (t, J ¼ 5:4 Hz, 1H), 4.39–4.22

(m, 2H), 4.20–4.05 (m, 2H), 4.00–3.85 (m, 1H), 2.22 (brs, 1H),

2.10–1.91 (m, 1H), 1.03 (d, J ¼ 6:4 Hz, 3H), 0.95 (d, J ¼ 6:6

Hz, 3H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 206.0, 155.5, 143.8,

141.1, 140.2, 138.7, 133.1, 128.6, 128.3, 128.0, 127.5, 127.4,

126.9, 126.0, 124.9, 119.9, 76.8, 66.9, 54.9, 52.5, 47.2, 30.4,

19.9, 15.5. HRMS (ESI) calcd for C₃₄H₃₄NO₄½M þ Hꢃ^þ

520.2488, found 520.2482.

syn,anti-18b: Colorless oil. IR (neat) 3415, 1716, 1663, 1513,

Y. Ogawa et al.

Bull. Chem. Soc. Jpn., 78, No. 7 (2005) 1325

(2S,3R)-2-Benzoyl-3-isopropylaziridine (22). The chiral

aziridinyl ketone 22 was prepared according to the literature pro-

anti-23a: Colorless oil. IR (neat) 3506, 3485, 1727, 1328,

1

1160 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 7.66 (d, J ¼ 8:1 Hz,

29

cedure.¹³½ꢃꢃ_D¼ ꢁ28:1 (c 1.69, CHCl₃, 95.5% ee by the HPLC

2H), 7.36–7.22 (m, 7H), 5.48 (dd, J ¼ 15:7, 8.6 Hz, 1H), 5.27

(dt, J ¼ 15:7, 5.9 Hz, 1H), 4.84 (dd, J ¼ 8:1, 4.6 Hz, 1H), 4.25

(t, J ¼ 5:9 Hz, 1H), 3.69 (s, 3H), 3.46–3.10 (m, 3H), 2.96 (d, J ¼

4:9 Hz, 1H), 2.43 (s, 3H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 172.8,

143.4, 140.7, 136.6, 129.9, 129.6, 128.3, 128.1, 127.6, 127.0,

126.4, 75.2, 56.4, 52.3, 44.8, 21.6. HRMS (ESI) calcd for

C₂₀H₂₃NNaO₅S ½M þ Naꢃ^þ412.1195, found 412.1173.

22

analysis), literature¹³½ꢃꢃ_D¼ ꢁ27:8 (c 1.56, CHCl₃). HPLC

(CHIRALCEL OD, 2-propanol–hexane 1:19, 1.0 mL/min) t_R

5.50 min for the major enantiomer (9.08 min for the minor one).

(2S,3R)-2-Benzoyl-3-isopropyl-1-tosylaziridine (5).

To a

solution of 2-benzoyl-3-isopropylaziridine (22) (225 mg, 1.19

mmol) and DMAP (363 mg, 2.97 mmol) in CH₂Cl₂(5 mL) was

added TsCl (272 mg, 1.43 mmol) at 0 ^ꢂC. After the reaction mix-

ture was stirred for 1 h at 0 ^ꢂC, the reaction mixture was quenched

with saturated aqueous ammonium chloride and was diluted with

ethyl acetate. It was extracted with ethyl acetate, and the organic

layer was washed with brine and dried over anhydrous sodium

sulfate. After evaporation of the solvent under reduced pressure,

the crude product was puriﬁed by column chromatography to

aﬀord (2S,3R)-2-benzoyl-3-isopropyl-1-tosylaziridine (5) (253

syn-23b: Colorless oil. IR (neat) 3497, 3278, 1732, 1514,

1

1159 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 7.69 (d, J ¼ 8:4 Hz,

2H), 7.29 (d, J ¼ 7:8 Hz, 2H), 7.17 (d, J ¼ 8:4 Hz, 2H), 6.83

(d, J ¼ 8:4 Hz, 2H), 5.73 (dd, J ¼ 15:1, 8.9 Hz, 1H), 5.43 (dt,

J ¼ 14:9, 5.4 Hz, 1H), 4.89 (d, J ¼ 6:2 Hz, 1H), 4.78 (t, J ¼

5:7 Hz, 1H), 3.79 (s, 3H), 3.58–3.43 (m, 5H), 3.23 (dd, J ¼ 8:9,

6.8 Hz, 1H), 2.98 (brs, 1H), 2.43 (s, 3H). ¹³C NMR (68 MHz,

CDCl₃) ꢁ 172.3, 159.0, 143.4, 136.5, 132.6, 130.6, 129.6, 127.4,

127.4, 127.0, 113.5, 73.7, 57.0, 55.2, 52.1, 44.8, 21.6. HRMS

(ESI) calcd for C₂₁H₂₅NNaO₆S ½M þ Naꢃ^þ442.1300, found

442.1298.

28

mg, 62%). ½ꢃꢃ_D¼ þ37:5 (c 0.96, CHCl₃).

(2S,3R,2⁰S)-5a: To a mixture of (2S,3R)-2-benzoyl-3-isopro-

pyl-1-tosylaziridine (5) (49.2 mg, 0.143 mmol) and 3-phenylpro-

panal (21.1 mg, 0.158 mmol) in THF (3 mL) at ꢁ78 ^ꢂC under

an argon atmosphere was added a solution of SmI₂in THF (0.1

M, 3.6 mL, 0.36 mmol). After the reaction mixture was stirred

anti-23b: Colorless oil. IR (neat) 3498, 3281, 1732, 1497,

1

1160 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 7.66 (d, J ¼ 8:1 Hz,

2H), 7.27 (d, J ¼ 7:8 Hz, 2H), 7.13 (d, J ¼ 6:8 Hz, 2H), 6.84

(d, J ¼ 6:8 Hz, 2H), 5.44 (dd, J ¼ 15:7, 8.9 Hz, 1H), 5.25 (dt,

J ¼ 15:7, 6.2 Hz, 1H), 4.79 (dd, J ¼ 8:4, 4.9 Hz, 1H), 4.36 (t, J ¼

6:2 Hz, 1H), 3.78 (s, 3H), 3.69 (s, 3H), 3.39 (t, J ¼ 6:2 Hz, 2H),

3.31 (t, J ¼ 8:4 Hz, 1H), 2.89 (d, J ¼ 4:6 Hz, 1H), 2.43 (s, 3H).

¹³C NMR (68 MHz, CDCl₃) ꢁ 172.9, 159.2, 143.4, 136.5, 132.8,

129.7, 129.6, 127.7, 127.6, 126.9, 113.6, 74.8, 56.5, 55.3, 52.2,

44.7, 21.6. HRMS (ESI) calcd for C₂₁H₂₅NNaO₆S ½M þ Naꢃ^þ

442.1300, found 442.1304.

ꢂ

for 1 h at ꢁ78 C, the reaction mixture was quenched with satu-

rated aqueous ammonium chloride and was diluted with ethyl ace-

tate. It was extracted with ethyl acetate, and the organic layer was

washed with brine and dried over anhydrous sodium sulfate. After

evaporation of the solvent under reduced pressure, the crude

product was puriﬁed by thin-layer chromatography to aﬀord

26

(2S,3R,2⁰S)-5a (57.2 mg, 83%). ½ꢃꢃ_D¼ þ67:9 (c 0.94, CHCl₃,

96.1% ee by the HPLC analysis). HPLC (CHIRALCEL OD, 2-

propanol–hexane 1:9, 1.0 mL/min) t_R18.59 min for the major

enantiomer (34.08 min for the minor one).

syn-23c: Colorless oil. IR (neat) 3498, 3281, 1731, 1327, 1159

.

cm^ꢁ1

¹H NMR (270 MHz, CDCl₃) ꢁ 7.70 (d, J ¼ 7:8 Hz, 2H),

28

(2S,3R,2⁰S)-5b: ½ꢃꢃ_D¼ þ60:7 (c 1.25, CHCl₃, 96.0% ee

7.33–7.14 (m, 6H), 5.71 (dd, J ¼ 15:7, 9.5 Hz, 1H), 5.45 (dt,

J ¼ 15:7, 5.4 Hz, 1H), 4.96 (d, J ¼ 5:4 Hz, 1H), 4.61 (t, J ¼

5:9 Hz, 1H), 3.59 (s, 3H), 3.53 (t, J ¼ 5:9 Hz, 2H), 3.22 (dd,

J ¼ 8:9, 5.7 Hz, 1H), 3.11 (s, 1H), 2.44 (s, 3H). ¹³C NMR (68

MHz, CDCl₃) ꢁ 172.3, 143.6, 138.9, 136.4, 133.5, 131.2, 129.7,

128.3, 127.5, 127.0, 126.5, 73.3, 56.6, 52.2, 44.8, 21.6. HRMS

(ESI) calcd for C₂₀H₂₂ClNNaO₅S ½M þ Naꢃ^þ446.0805, found

446.0814.

by the HPLC analysis). HPLC (CHIRALCEL OD, 2-propanol–

hexane 1:9, 1.0 mL/min) t_R14.32 min for the major enantiomer

(12.42 min for the minor one).

Typical Procedure for Samarium(II) Iodide-Mediated Aldol

Reaction of ꢂ,ꢁ-Aziridinyl–ꢃ,ꢀ-Unsaturated Ester with Alde-

hyde. (Table 7, Entry 5). To a mixture of methyl (2E)-3-

[(2R)-1-tosylaziridin-2-yl]acrylate (23) (49.5 mg, 0.176 mmol)

and 3-phenylpropanal (26.0 mg, 0.194 mmol) in THF (4 mL) at

ꢁ78 ^ꢂC under an argon atmosphere was added a solution of SmI₂

in THF (0.1 M, 4.4 mL, 0.44 mmol). After the reaction mixture

was stirred for 30 min at ꢁ78 ^ꢂC, the reaction mixture was

quenched with saturated aqueous ammonium chloride and was di-

luted with ethyl acetate. It was extracted with ethyl acetate, and

the organic layer was washed with brine and dried over anhydrous

sodium sulfate. The crude product was obtained after evaporation

of the solvent under reduced pressure, and puriﬁcation by thin-lay-

er chromatography aﬀorded syn-23e (36.0 mg, 49%) and anti-23e

(34.6 mg, 47%), respectively.

anti-23c: Colorless oil. IR (neat) 3491, 3280, 1727, 1327,

1

1160 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 7.67 (d, J ¼ 8:4 Hz,

2H), 7.31–7.14 (m, 6H), 5.48 (dd, J ¼ 15:4, 8.9 Hz, 1H), 5.33

(dt, J ¼ 15:2, 5.9 Hz, 1H), 4.82 (dd, J ¼ 7:3, 4.9 Hz, 1H), 4.60

(t, J ¼ 6:2 Hz, 1H), 3.68 (s, 3H), 3.42 (t, J ¼ 5:7 Hz, 2H), 3.30

(t, J ¼ 8:4 Hz, 1H), 3.18 (d, J ¼ 5:6 Hz, 1H), 2.43 (s, 3H).

¹³C NMR (68 MHz, CDCl₃) ꢁ 172.7, 143.5, 139.2, 136.5, 133.6,

130.3, 129.6, 128.4, 127.7, 126.9, 126.9, 74.4, 56.2, 52.3, 44.6,

21.6. HRMS (ESI) calcd for C₂₀H₂₂ClNNaO₅S ½M þ Naꢃ^þ

446.0805, found 446.0789.

syn-23d: Colorless oil. IR (neat) 3502, 3279, 1731, 1327,

1

syn-23a: Colorless oil. IR (neat) 3500, 3282, 1732, 1328, 1160

.

1160 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 7.74 (d, J ¼ 8:4 Hz,

cm^ꢁ1

¹H NMR (270 MHz, CDCl₃) ꢁ 7.71 (d, J ¼ 8:1 Hz, 2H),

2H), 7.31 (d, J ¼ 8:4 Hz, 2H), 5.72 (dd, J ¼ 15:7, 8.9 Hz, 1H),

5.56 (dt, J ¼ 15:7, 5.9 Hz, 1H), 4.83 (t, J ¼ 5:9 Hz, 1H), 3.84–

3.75 (m, 1H), 3.69 (s, 3H), 3.57 (t, J ¼ 5:9 Hz, 2H), 3.02 (dd,

J ¼ 8:6, 4.3 Hz, 1H), 2.43 (s, 3H), 1.46–1.28 (m, 2H), 0.92 (t, J ¼

7:6 Hz, 3H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 173.4, 143.5, 136.6,

130.5, 129.6, 127.0, 127.0, 72.9, 53.8, 52.2, 45.0, 27.2, 21.6,

10.1. HRMS (ESI) calcd for C₁₆H₂₄NO₅S ½M þ Hꢃ^þ342.1375,

found 342.1371.

7.33–7.25 (m, 7H), 5.74 (dd, J ¼ 15:4, 9.2 Hz, 1H), 5.40 (dt,

J ¼ 15:7, 6.2 Hz, 1H), 5.02 (d, J ¼ 3:8 Hz, 1H), 4.39 (t, J ¼

5:9 Hz, 1H), 3.59 (s, 3H), 3.51 (t, J ¼ 5:9 Hz, 2H), 3.26 (dd,

J ¼ 8:9, 5.4 Hz, 1H), 2.90 (s, 1H), 2.44 (s, 3H). ¹³C NMR (68

MHz, CDCl₃) ꢁ 172.5, 143.5, 140.4, 130.7, 129.7, 128.3, 128.2,

127.9, 127.0, 127.0, 126.1, 73.9, 56.6, 52.2, 44.9, 21.6. HRMS

(ESI) calcd for C₂₀H₂₃NNaO₅S ½M þ Naꢃ^þ412.1195, found

412.1204.

anti-23d: Colorless oil. IR (neat) 3506, 3279, 1730, 1328,

1326 Bull. Chem. Soc. Jpn., 78, No. 7 (2005)

SmI₂-Mediated Aldol Reactions of Acylaziridines

1

1160 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 7.74 (d, J ¼ 8:4 Hz,

1161 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 7.74 (d, J ¼ 8:4 Hz,

2H), 7.31 (d, J ¼ 8:4 Hz, 2H), 5.65 (dd, J ¼ 15:7, 7.8 Hz, 1H),

5.55 (dt, J ¼ 15:4, 5.4 Hz, 1H), 4.79 (t, J ¼ 6:2 Hz, 1H), 3.68

(s, 3H), 3.56 (t, J ¼ 5:9 Hz, 2H), 3.51–3.42 (m, 1H), 3.23 (t, J ¼

7:8 Hz, 1H), 2.52 (d, J ¼ 7:6 Hz, 1H), 2.43 (s, 3H), 1.80–1.45 (m,

5H), 1.40–0.98 (m, 6H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 173.5,

143.4, 136.6, 129.6, 129.0, 128.6, 127.0, 76.8, 52.1, 51.6, 44.9,

40.8, 30.0, 26.5, 26.3, 26.2, 26.0, 21.6. HRMS (ESI) calcd for

C₂₀H₃₀NO₅S ½M þ Hꢃ^þ396.1845, found 396.1850.

2H), 7.32 (d, J ¼ 8:4 Hz, 2H), 5.63–5.54 (m, 2H), 4.68 (t, J ¼

6:3 Hz, 1H), 3.69 (s, 3H), 3.68–3.59 (m, 1H), 3.57 (t, J ¼ 5:7

Hz, 2H), 3.07 (t, J ¼ 7:6 Hz, 1H), 2.48–2.43 (m, 1H), 2.43 (s,

3H), 1.55–1.42 (m, 1H), 1.40–1.23 (m, 1H), 0.94 (t, J ¼ 7:3 Hz,

3H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 173.1, 143.5, 136.7, 129.7,

129.6, 128.1, 127.0, 73.8, 54.7, 52.1, 44.9, 27.6, 21.6, 9.9. HRMS

(ESI) calcd for C₁₆H₂₄NO₅S ½M þ Hꢃ^þ342.1375, found

342.1372.

syn-23e: Colorless oil. IR (neat) 3506, 3279, 1731, 1327, 1160

.

syn-23h: Colorless oil. IR (neat) 3529, 3279, 1732, 1328,

cm^ꢁ1

¹H NMR (270 MHz, CDCl₃) ꢁ 7.73 (d, J ¼ 8:1 Hz, 2H),

1160 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 7.74 (d, J ¼ 8:4 Hz,

1

7.31–7.14 (m, 7H), 5.72 (dd, J ¼ 15:4, 9.2 Hz, 1H), 5.57 (dt,

J ¼ 15:7, 5.4 Hz, 1H), 4.81 (t, J ¼ 6:2 Hz, 1H), 3.89 (dt,

J ¼ 8:9, 4.3 Hz, 1H), 3.67 (s, 3H), 3.54 (t, J ¼ 5:7 Hz, 2H),

3.01 (dd, J ¼ 8:9, 4.3 Hz, 1H), 2.88–2.74 (m, 1H), 2.68–2.56

(m, 1H), 2.42 (s, 3H), 1.77–1.56 (m, 2H). ¹³C NMR (68 MHz,

CDCl₃) ꢁ 173.2, 143.5, 141.5, 136.8, 130.7, 129.7, 128.3, 128.3,

127.0, 126.9, 125.8, 70.7, 54.3, 52.2, 44.9, 36.0, 31.9, 21.6. HRMS

(ESI) calcd for C₂₂H₂₈NO₅S ½M þ Hꢃ^þ418.1688, found

418.1710.

2H), 7.31 (d, J ¼ 8:4 Hz, 2H), 5.79 (dd, J ¼ 15:7, 9.2 Hz, 1H),

5.59 (dt, J ¼ 15:4, 6.2 Hz, 1H), 4.86 (t, J ¼ 6:2 Hz, 1H), 3.66

(s, 3H), 3.65–3.58 (m, 1H), 3.55 (t, J ¼ 5:9 Hz, 2H), 3.24 (dd,

J ¼ 9:2, 4.9 Hz, 1H), 2.59 (brs, 1H), 2.43 (s, 3H), 0.87 (s, 9H).

¹³C NMR (68 MHz, CDCl₃) ꢁ 173.9, 143.4, 136.5, 130.6, 129.6,

128.6, 127.0, 78.0, 52.2, 51.0, 45.0, 35.6, 26.4, 21.6. HRMS

(ESI) calcd for C₁₈H₂₇NNaO₅S ½M þ Naꢃ^þ392.1508, found

392.1464.

anti-23h: Colorless oil. IR (neat) 3512, 3278, 1717, 1329,

1

anti-23e: Colorless oil. IR (neat) 3505, 3280, 1732, 1327,

1

1160 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 7.74 (d, J ¼ 8:4 Hz,

1160 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 7.72 (d, J ¼ 8:1 Hz,

2H), 7.31 (d, J ¼ 8:4 Hz, 2H), 5.79 (dd, J ¼ 15:4, 8.1 Hz, 1H),

5.57 (dt, J ¼ 15:7, 6.2 Hz, 1H), 4.82 (t, J ¼ 6:2 Hz, 1H), 3.67

(s, 3H), 3.60–3.47 (m, 3H), 3.31–3.20 (m, 2H), 2.43 (s, 3H),

0.87 (s, 9H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 174.2, 143.4, 136.7,

130.6, 129.6, 128.2, 127.0, 81.4, 52.2, 48.5, 44.9, 36.0, 26.2,

21.6. HRMS (ESI) calcd for C₁₈H₂₇NNaO₅S ½M þ Naꢃ^þ

392.1508, found 392.1490.

2H), 7.29–7.14 (m, 7H), 5.61 (dd, J ¼ 15:9, 9.5 Hz, 1H), 5.56

(dt, J ¼ 15:9, 5.9 Hz, 1H), 4.75 (t, J ¼ 6:2 Hz, 1H), 3.81–3.68

(m, 1H), 3.67 (s, 3H), 3.56 (t, J ¼ 5:9 Hz, 2H), 3.07 (t, J ¼ 7:3

Hz, 1H), 2.88–2.76 (m, 1H), 2.69–2.56 (m, 1H), 2.41 (s, 3H),

1.77–1.57 (m, 2H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 173.2, 143.5,

141.5, 136.6, 129.8, 129.6, 128.3, 128.3, 127.8, 127.0, 125.8,

71.7, 55.0, 52.1, 44.9, 36.4, 31.8, 21.6. HRMS (ESI) calcd for

C₂₂H₂₈NO₅S ½M þ Hꢃ^þ418.1688, found 418.1718.

Acetonide 24. To a solution of syn-23e (76 mg, 0.18 mmol) in

CH₂Cl₂(5 mL) at ꢁ78 ^ꢂC under an argon atmosphere was added a

solution of DIBAL in toluene (1.1 M, 8.2 mL, 9 mmol). After the

syn-23f: Colorless oil. IR (neat) 3520, 3280, 1731, 1328, 1160

cm^ꢁ1

.

¹H NMR (270 MHz, CDCl₃) ꢁ 7.74 (d, J ¼ 8:4 Hz, 2H),

reaction mixture was stirred for 2 h at ꢁ20 C, the reaction mix-

ꢂ

7.32 (d, J ¼ 8:4 Hz, 2H), 5.73 (dd, J ¼ 15:7, 9.2 Hz, 1H), 5.59

(dt, J ¼ 15:4, 5.7 Hz, 1H), 4.81 (t, J ¼ 6:2 Hz, 1H), 3.68 (s,

3H), 3.68–3.58 (m, 1H), 3.57 (t, J ¼ 6:2 Hz, 2H), 3.18 (dd,

J ¼ 8:6, 4.3 Hz, 1H), 2.43 (s, 3H), 1.61–1.47 (m, 1H), 0.95 (d,

J ¼ 6:8 Hz, 3H), 0.78 (d, J ¼ 6:8 Hz, 3H). ¹³C NMR (68 MHz,

CDCl₃) ꢁ 173.6, 143.5, 136.6, 130.2, 129.6, 127.1, 127.0, 76.4,

52.2, 51.8, 45.0, 30.8, 21.6, 19.2, 17.8. HRMS (ESI) calcd for

C₁₇H₂₆NO₅S ½M þ Hꢃ^þ356.1532, found 356.1522.

ture was quenched with saturated aqueous ammonium chloride

and then it was allowed to warm to 0 ^ꢂC. The reaction mixture

was made acidic with 5% HCl aq and extracted with CH₂Cl₂,

and the organic layer was washed with brine and dried over anhy-

drous sodium sulfate. The crude product was obtained after evap-

oration of the solvent under reduced pressure, and puriﬁcation by

thin-layer chromatography aﬀorded syn-diol (48 mg, 68%). Color-

less oil. IR (neat) 3478, 3294, 1324, 1158 cm^ꢁ^{1 1}H NMR (270

.

anti-23f: Colorless oil. IR (neat) 3518, 3279, 1724, 1328,

MHz, CDCl₃) ꢁ 7.74 (d, J ¼ 8:4 Hz, 2H), 7.31–7.15 (m, 7H),

5.72 (dd, J ¼ 15:4, 8.4 Hz, 1H), 5.55 (dt, J ¼ 15:7, 5.9 Hz,

1H), 4.95 (brs, 1H), 3.83–3.75 (m, 1H), 3.72 (d, J ¼ 5:4 Hz,

2H), 3.56 (brs, 2H), 2.84–2.70 (m, 1H), 2.68–2.55 (m, 1H), 2.41

(s, 3H), 2.23–2.12 (m, 1H), 1.78–1.51 (m, 2H). ¹³C NMR (68

MHz, CDCl₃) ꢁ 143.5, 141.6, 136.5, 129.9, 129.7, 129.0, 128.3,

127.0, 125.8, 72.5, 65.3, 49.3, 45.2, 37.0, 32.2, 21.6. HRMS

(ESI) calcd for C₂₁H₂₇NNaO₄S ½M þ Naꢃ^þ412.1559, found

412.1532. To a solution of syn-diol (48 mg, 0.12 mmol) in 2,2-di-

methoxypropane (2 mL) in CH₂Cl₂(2 mL) at 0 ^ꢂC was added 10-

camphorsulfonic acid (CSA) (2 mg). After the reaction mixture

was stirred for 2 h at room temperature, the reaction mixture

was quenched with Et₃N. The crude product was obtained after

evaporation of the solvent under reduced pressure, and puriﬁca-

tion by thin-layer chromatography aﬀorded acetonide 24 (35

1

1160 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 7.74 (d, J ¼ 8:4 Hz,

2H), 7.31 (d, J ¼ 8:4 Hz, 2H), 5.68–5.56 (m, 2H), 4.69 (t, J ¼

6:5 Hz, 1H), 3.69 (s, 3H), 3.56 (dd, J ¼ 6:2, 4.6 Hz, 2H), 3.53–

3.47 (m, 1H), 3.18 (t, J ¼ 7:8 Hz, 1H), 2.43 (s, 3H), 1.68–1.57

(m, 1H), 0.93 (d, J ¼ 7:0 Hz, 3H), 0.85 (d, J ¼ 6:8 Hz, 3H).

¹³C NMR (68 MHz, CDCl₃) ꢁ 173.4, 143.5, 136.7, 129.6, 129.1,

128.4, 127.0, 77.1, 52.5, 52.1, 44.9, 30.8, 21.6, 19.9, 15.8. HRMS

(ESI) calcd for C₁₇H₂₆NO₅S ½M þ Hꢃ^þ356.1532, found

356.1515.

syn-23g: Colorless oil. IR (neat) 3466, 3273, 1710, 1335, 1165

.

cm^ꢁ1

¹H NMR (270 MHz, CDCl₃) ꢁ 7.74 (d, J ¼ 8:4 Hz, 2H),

7.31 (d, J ¼ 8:4 Hz, 2H), 5.73 (dd, J ¼ 15:7, 8.9 Hz, 1H), 5.58

(dt, J ¼ 15:4, 5.7 Hz, 1H), 4.86 (t, J ¼ 6:2 Hz, 1H), 3.68 (s,

3H), 3.64–3.58 (m, 1H), 3.57 (t, J ¼ 5:7 Hz, 2H), 3.21 (dd,

J ¼ 9:2, 4.6 Hz, 1H), 2.69 (d, J ¼ 3:8 Hz, 1H), 2.43 (s, 3H),

1.96–1.89 (m, 1H), 1.73–1.58 (m, 3H), 1.55–1.48 (m, 1H),

1.26–0.94 (m, 6H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 173.7, 143.4,

136.5, 130.1, 129.6, 127.1, 127.0, 75.5, 52.2, 51.2, 45.0, 40.2,

29.1, 28.2, 26.3, 26.0, 25.8, 21.6. HRMS (ESI) calcd for

C₂₀H₃₀NO₅S ½M þ Hꢃ^þ396.1845, found 396.1855.

mg, 66%). Colorless oil. IR (neat) 3278, 1329, 1161 cm^ꢁ1

.

¹H NMR (270 MHz, C₆D₆) ꢁ 7.83 (d, J ¼ 8:2 Hz, 2H), 7.32–

7.16 (m, 5H), 6.89 (d, J ¼ 8:2 Hz, 2H), 6.03 (dd, J ¼ 15:5, 9.7

Hz, 1H), 5.30 (dt, J ¼ 15:6, 6.1 Hz, 1H), 4.31 (t, J ¼ 6:1 Hz,

1H), 3.76 (dd, J ¼ 11:3, 2.8 Hz, 1H), 3.67 (ddd, J ¼ 8:9, 4.0,

2.4 Hz, 1H), 3.52 (dd, J ¼ 11:4, 1.6 Hz, 1H), 3.43 (dt,

J ¼ 14:4, 6.1 Hz, 1H), 3.36 (dt, J ¼ 14:4, 6.4 Hz, 1H), 2.75

anti-23g: Colorless oil. IR (neat) 3519, 3277, 1725, 1329,

Y. Ogawa et al.

Bull. Chem. Soc. Jpn., 78, No. 7 (2005) 1327

(ddd, J ¼ 13:8, 8.9, 5.5 Hz, 1H), 2.63 (dt, J ¼ 13:8, 8.3 Hz, 1H),

2.02 (s, 3H), 1.82 (ddt, J ¼ 14:0, 5.2, 8.8 Hz, 1H), 1.57 (s, 3H),

1.44 (ddt, J ¼ 14:3, 4.0, 7.9 Hz, 1H), 1.40–1.36 (m, 1H), 1.36

(s, 3H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 143.3, 141.5, 136.6,

131.8, 129.6, 128.4, 128.2, 127.0, 127.0, 125.8, 98.9, 69.8, 65.6,

45.5, 41.7, 35.3, 31.2, 29.7, 21.6, 19.1. HRMS (ESI) calcd for

C₂₄H₃₁NNaO₄S ½M þ Naꢃ^þ452.1872, found 452.1856.

1H), 3.70 (s, 3H), 3.56 (t, J ¼ 5:9 Hz, 2H), 3.24 (brs, 1H), 3.09

(d, J ¼ 9:5 Hz, 1H), 2.76–2.56 (m, 2H), 2.41 (s, 3H), 1.80–1.54

(m, 2H), 1.23 (s, 3H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 173.7,

141.9, 136.6, 130.5, 129.7, 128.3, 128.2, 127.7, 127.6, 127.0,

125.8, 73.0, 57.7, 52.1, 45.0, 41.2, 29.8, 25.3, 21.6. HRMS

(ESI) calcd for C₂₃H₃₀NO₅S ½M þ Hꢃ^þ432.1845, found

432.1851.

Acetonide 25. To a solution of anti-23e (20.1 mg, 0.048

23j: Colorless oil. IR (neat) 3508, 3279, 1731, 1329, 1160

.

ꢂ

mmol) in CH₂Cl₂(1 mL) at ꢁ78 C under an argon atmosphere

cm^ꢁ1

¹H NMR (270 MHz, CDCl₃) ꢁ 7.73 (d, J ¼ 8:4 Hz, 2H),

was added a solution of DIBAL in toluene (1.1 M, 0.2 mL, 0.22

mmol). After the reaction mixture was stirred for 2 h at ꢁ20

^ꢂC, the reaction mixture was quenched with saturated aque_ꢂous am-

monium chloride and then it was allowed to warm at 0 C. The

reaction mixture was made acidic with 5% HCl aq and extracted

with CH₂Cl₂, and the organic layer was washed with brine and

dried over anhydrous sodium sulfate. The crude product was ob-

tained after evaporation of the solvent under reduced pressure,

and puriﬁcation by thin-layer chromatography aﬀorded anti-diol

(10.5 mg, 54%). Colorless oil. IR (neat) 3479, 3291, 1324, 1158

7.31 (d, J ¼ 8:4 Hz, 2H), 5.75 (dd, J ¼ 15:7, 9.4 Hz, 1H), 5.57

(dt, J ¼ 15:7, 6.2 Hz, 1H), 4.77 (t, J ¼ 5:9 Hz, 1H), 3.70 (s,

3H), 3.57 (t, J ¼ 6:2 Hz, 2H), 3.16 (s, 1H), 2.98 (d, J ¼ 9:5 Hz,

1H), 2.43 (s, 3H), 1.20 (s, 3H), 1.12 (s, 3H). ¹³C NMR (68

MHz, CDCl₃) ꢁ 173.6, 143.5, 136.6, 130.3, 129.7, 128.0, 127.0,

71.4, 58.7, 52.0, 45.0, 28.5, 26.7, 21.6. HRMS (ESI) calcd for

C₁₆H₂₄NO₅S ½M þ Hꢃ^þ342.1375, found 342.1381.

23k: Colorless oil. IR (neat) 3521, 3280, 1729, 1329, 1161

cm^ꢁ1

.

¹H NMR (270 MHz, CDCl₃) ꢁ 7.73 (d, J ¼ 8:4 Hz, 2H),

7.30 (d, J ¼ 8:4 Hz, 2H), 5.76 (dd, J ¼ 15:4, 9.5 Hz, 1H), 5.58

(dt, J ¼ 15:4, 5.9 Hz, 1H), 4.76 (t, J ¼ 6:2 Hz, 1H), 3.69 (s,

3H), 3.54 (t, J ¼ 5:9 Hz, 2H), 3.14 (s, 1H), 3.09 (d, J ¼ 5:9 Hz,

1H), 2.43 (s, 3H), 1.81–1.19 (m, 4H), 0.84 (t, J ¼ 7:6 Hz, 3H),

0.76 (t, J ¼ 7:6 Hz, 3H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 174.1,

143.4, 136.6, 129.9, 129.6, 127.9, 127.0, 75.4, 54.9, 52.0, 45.0,

29.5, 27.1, 21.6, 7.7, 7.4. HRMS (ESI) calcd for C₁₈H₂₈NO₅S

½M þ Hꢃ^þ370.1688, found 370.1693.

cm^ꢁ1

.

¹H NMR (270 MHz, CDCl₃) ꢁ 7.73 (d, J ¼ 8:1 Hz, 2H),

7.31–7.15 (m, 7H), 5.79–5.42 (m, 2H), 4.84 (brs, 1H), 3.78–

3.65 (m, 3H), 3.52 (brs, 2H), 2.88–2.75 (m, 1H), 2.65–2.55 (m,

1H), 2.42 (s, 3H), 2.33–2.15 (m, 1H), 1.78–1.56 (m, 2H).

¹³C NMR (68 MHz, CDCl₃) ꢁ 143.5, 141.7, 136.5, 131.6, 129.7,

128.4, 128.3, 128.2, 127.0, 125.8, 73.6, 64.6, 49.8, 45.1, 37.2,

31.9, 21.6. HRMS (ESI) calcd for C₂₁H₂₇NNaO₄S ½M þ Naꢃ^þ

412.1559, found 412.1523. To a solution of anti-diol (10.0 mg,

0.026 mmol) in 2,2-dimethoxypropane (1 mL) and CH₂Cl₂(1

23l: Colorless oil. IR (neat) 3517, 3280, 1729, 1330, 1161

cm^ꢁ1

.

¹H NMR (270 MHz, CDCl₃) ꢁ 7.74 (d, J ¼ 8:4 Hz, 2H),

ꢂ

mL) at 0 C was added CSA (1 mg). After the reaction mixture

7.31 (d, J ¼ 8:4 Hz, 2H), 5.76 (dd, J ¼ 15:6, 9.7 Hz, 1H), 5.55

(dt, J ¼ 15:7, 6.2 Hz, 1H), 4.86 (t, J ¼ 6:2 Hz, 1H), 3.68 (s,

3H), 3.56 (t, J ¼ 6:2 Hz, 2H), 3.04 (s, 1H), 3.01 (d, J ¼ 9:5 Hz,

1H), 2.43 (s, 3H), 1.62–1.32 (m, 8H), 1.29–1.15 (m, 2H).

¹³C NMR (68 MHz, CDCl₃) ꢁ 174.7, 143.4, 136.6, 130.1, 129.6,

127.7, 127.0, 72.1, 57.7, 52.0, 45.0, 36.6, 34.7, 25.5, 21.8, 21.6,

21.5. HRMS (ESI) calcd for C₁₉H₂₈NO₅S ½M þ Hꢃ^þ382.1688,

found 382.1707.

was stirred for 2 h at room temperature, the reaction mixture

was quenched with Et₃N. The crude product was obtained after

evaporation of the solvent under reduced pressure, and puriﬁca-

tion by thin-layer chromatography aﬀorded acetonide 25 (8.5

mg, 77%). Colorless oil. IR (neat) 3277, 1330, 1161 cm^ꢁ1

.

¹H NMR (270 MHz, C₆D₆) ꢁ 7.86 (d, J ¼ 8:2 Hz, 2H), 7.31–

7.24 (m, 4H), 7.17 (t, J ¼ 6:9 Hz, 1H), 6.88 (d, J ¼ 7:9 Hz,

2H), 5.06 (dt, J ¼ 15:2, 7.8 Hz, 1H), 4.81 (dd, J ¼ 15:3, 8.9

Hz, 1H), 4.62 (t, J ¼ 6:2 Hz, 1H), 3.60 (dd, J ¼ 11:6, 5.2 Hz,

1H), 3.48 (dt, J ¼ 2:4, 9.8 Hz, 1H), 3.44 (t, J ¼ 11:3 Hz, 1H),

3.30 (t, J ¼ 6:1 Hz, 2H), 2.95 (ddd, J ¼ 13:8, 9.2, 3.4 Hz, 1H),

2.78 (dt, J ¼ 13:5, 8.3 Hz, 1H), 2.17 (dq, J ¼ 5:2, 10.4 Hz,

1H), 2.00 (s, 3H), 1.89–1.83 (m, 1H), 1.72 (ddt, J ¼ 13:7, 9.1,

4.5 Hz, 1H), 1.65 (s, 3H), 1.40 (s, 3H). ¹³C NMR (68 MHz,

CDCl₃) ꢁ 143.4, 141.9, 136.8, 129.9, 129.6, 128.6, 128.5, 128.2,

127.0, 125.6, 98.2, 71.1, 63.8, 45.0, 43.8, 35.3, 31.0, 29.7, 21.6,

19.1. HRMS (ESI) calcd for C₂₄H₃₁NNaO₄S ½M þ Naꢃ^þ

452.1872, found 452.1854.

23

26a (Less Polar Isomer): Colorless oil. ½ꢃꢃ_D¼ ꢁ111 (c

0.82, CHCl₃). IR (neat) 3505, 3276, 1732, 1327, 1161 cm^ꢁ1

.

¹H NMR (270 MHz, CDCl₃) ꢁ 7.74 (d, J ¼ 8:4 Hz, 2H), 7.30

(d, J ¼ 8:4 Hz, 2H), 5.65 (dd, J ¼ 16:2, 9.2 Hz, 1H), 5.51 (dd,

J ¼ 15:7, 6.5 Hz, 1H), 4.83 (dq, J ¼ 6:5, 6.2 Hz, 1H), 4.61 (d,

J ¼ 6:8 Hz, 1H), 3.69 (s, 3H), 3.12 (s, 1H), 2.96 (d, J ¼ 9:2

Hz, 1H), 2.43 (s, 3H), 1.19 (s, 3H), 1.18 (d, J ¼ 6:2 Hz, 1H),

1.13 (s, 3H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 173.5, 143.4, 137.4,

136.6, 129.6, 127.0, 125.4, 71.4, 58.9, 52.0, 51.2, 28.1, 26.8,

21.8, 21.6. HRMS (ESI) calcd for C₁₇H₂₅NNaO₅S ½M þ Naꢃ^þ

378.1351, found 378.1319.

23

23i (Less Polar Isomer): Colorless oil. IR (neat) 3508, 3281,

1731, 1330, 1160 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 7.73 (d,

26a (More Polar Isomer): Colorless oil. ½ꢃꢃ_D¼ þ48:1 (c

1

1.04, CHCl₃). IR (neat) 3509, 3277, 1732, 1327, 1160 cm^ꢁ1

.

J ¼ 8:1 Hz, 2H), 7.31–7.12 (m, 7H), 5.76 (dd, J ¼ 15:1, 9.7

Hz, 1H), 5.59 (dt, J ¼ 15:7, 5.9 Hz, 1H), 4.58 (t, J ¼ 6:5 Hz,

1H), 3.69 (s, 3H), 3.55 (t, J ¼ 5:9 Hz, 2H), 3.23 (brs, 1H), 3.09

(d, J ¼ 9:5 Hz, 1H), 2.76–2.61 (m, 2H), 2.42 (s, 3H), 1.80–1.57

(m, 2H), 1.15 (s, 3H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 173.7,

143.5, 141.9, 130.4, 129.7, 128.3, 128.2, 127.8, 127.6, 127.0,

125.8, 73.2, 57.5, 52.2, 45.0, 43.3, 30.1, 23.6, 21.6. HRMS

(ESI) calcd for C₂₃H₃₀NO₅S ½M þ Hꢃ^þ432.1845, found

432.1833.

¹H NMR (270 MHz, CDCl₃) ꢁ 7.74 (d, J ¼ 8:4 Hz, 2H), 7.29

(d, J ¼ 8:4 Hz, 2H), 5.64 (dd, J ¼ 15:4, 9.5 Hz, 1H), 5.47 (dd,

J ¼ 15:4, 5.7 Hz, 1H), 4.80 (d, J ¼ 7:6 Hz, 1H), 3.86 (dq,

J ¼ 5:7, 6.2 Hz, 1H), 3.71 (s, 3H), 3.11 (s, 1H), 2.92 (d, J ¼

9:2 Hz, 1H), 2.43 (s, 3H), 1.18 (d, J ¼ 6:2 Hz, 1H), 1.16 (s,

3H), 1.09 (s, 3H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 173.6, 143.2,

137.6, 136.3, 129.5, 127.0, 125.1, 71.3, 58.7, 52.0, 50.8, 28.5,

26.6, 21.7, 21.6. HRMS (ESI) calcd for C₁₇H₂₅NNaO₅S ½M þ

Naꢃ^þ378.1351, found 378.1339.

23i (More Polar Isomer): Colorless oil. IR (neat) 3511, 3279,

1

Typical Procedure for the Preparation of ꢂ,ꢁ-Aziridinyl–

ꢃ,ꢀ-Unsaturated Ester. To a solution of methyl (2R)-1-tosyl-

aziridine-2-carboxylate (300 mg, 1.11 mmol) in CH₂Cl₂(5 mL)

at ꢁ78 ^ꢂC under argon atmosphere was added a solution of

1731, 1330, 1160 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 7.72 (d,

J ¼ 8:1 Hz, 2H), 7.31–7.12 (m, 7H), 5.77 (dd, J ¼ 15:4, 9.2

Hz, 1H), 5.58 (dt, J ¼ 15:1, 6.2 Hz, 1H), 4.72 (t, J ¼ 6:2 Hz,

1328 Bull. Chem. Soc. Jpn., 78, No. 7 (2005)

SmI₂-Mediated Aldol Reactions of Acylaziridines

DIBAL in toluene (1.1 M, 1.23 mL, 1.23 mmol). After the reac-

tion mixture was stirred for 1 h, NH₄Cl aq (1 mL) was added to

it with stirring at ꢁ78 C, followed by a solution of the sodium

drous sodium sulfate. The crude product was obtained after evap-

oration of the solvent under reduced pressure, and puriﬁcation by

thin-layer chromatography aﬀorded syn-30a (64.9 mg, 87%) and

anti-30a (7.2 mg, 10%), respectively.

ꢂ

salt of diethylphosphonoacetic acid benzyl ester (0.48 M solution

in DMF; 7 mL, 3.33 mmol). After the reaction mixture was stirred

for 3 h, it was quenched with 1 M HCl aq. Then, it was extracted

with ethyl acetate, and the organic layer was washed with brine

and dried over anhydrous sodium sulfate. The crude product

was obtained after evaporation of the solvent under reduced pres-

sure, and puriﬁcation by column chromatography aﬀorded benzyl

ester 27 (235 mg, 59%).

syn-27a: Colorless oil. IR (neat) 3516, 3281, 1730, 1328, 1159

.

cm^ꢁ1

¹H NMR (270 MHz, CDCl₃) ꢁ 7.71 (d, J ¼ 8:4 Hz, 2H),

7.34–7.05 (m, 12H), 5.73 (dd, J ¼ 15:4, 8.9 Hz, 1H), 5.56 (dt,

J ¼ 15:4, 5.7 Hz, 1H), 5.09 (s, 2H), 4.88 (t, J ¼ 5:7 Hz, 1H),

3.95–3.79 (m, 1H), 3.53 (t, J ¼ 5:7 Hz, 2H), 3.04 (dd, J ¼ 8:9,

4.6 Hz, 1H), 2.91–2.70 (m, 2H), 2.65–2.52 (m, 1H), 2.40 (s,

3H), 1.75–1.48 (m, 2H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 172.5,

143.4, 141.4, 136.4, 135.2, 130.8, 129.6, 128.6, 128.3, 128.3,

128.1, 127.0, 126.9, 125.8, 70.7, 66.8, 54.5, 44.9, 36.0, 31.9,

21.6. HRMS (ESI) calcd for C₂₈H₃₁NNaO₅S ½M þ Naꢃ^þ

516.1821, found 516.1800.

Benzyl (2E)-3-[(2R)-1-Tosylaziridin-2-yl]acrylate (27):

17

Colorless oil. ½ꢃꢃ_D¼ ꢁ41:6 (c 1.07, CHCl₃). IR (neat) 1721,

1328, 1163 cm^ꢁ1

.

¹H NMR (270 MHz, CDCl₃) ꢁ 7.81 (d, J ¼

8:1 Hz, 2H), 7.41–7.23 (m, 7H), 6.58 (dd, J ¼ 15:4, 7.6 Hz,

1H), 6.15 (d, J ¼ 15:7 Hz, 1H), 5.15 (s, 2H), 3.38–3.26 (m,

1H), 2.86 (d, J ¼ 7:0 Hz, 1H), 2.44 (s, 3H), 2.26 (d, J ¼ 3:2

Hz, 1H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 164.9, 144.8, 142.1,

135.4, 134.3, 129.7, 128.4, 128.2, 128.2, 127.8, 124.8, 66.5,

38.5, 34.7, 21.8. HRMS (ESI) calcd for C₁₉H₁₉NNaO₄S ½M þ

Naꢃ^þ380.0933, found 380.0962.

anti-27a: Colorless oil. IR (neat) 3507, 3282, 1730, 1328,

1

1159 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 7.70 (d, J ¼ 8:4 Hz,

2H), 7.34–7.09 (m, 12H), 5.61 (dd, J ¼ 15:7, 7.0 Hz, 1H), 5.54

(dt, J ¼ 15:7, 5.2 Hz, 1H), 5.11 (s, 2H), 4.53 (t, J ¼ 5:9 Hz,

1H), 3.81–3.69 (m, 1H), 3.51 (t, J ¼ 5:1 Hz, 2H), 3.11 (t, J ¼

7:0 Hz, 1H), 2.85–2.74 (m, 1H), 2.69–2.48 (m, 1H), 2.40 (s,

3H), 1.79–1.56 (m, 2H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 172.3,

143.5, 141.4, 136.5, 135.3, 129.9, 129.6, 128.5, 128.3, 128.1,

127.8, 127.0, 125.8, 71.8, 66.7, 55.0, 44.9, 36.4, 31.8, 21.6. HRMS

(ESI) calcd for C₂₈H₃₁NNaO₅S ½M þ Naꢃ^þ516.1821, found

516.1804.

t-Butyl (2E)-3-[(2R)-1-Tosylaziridin-2-yl]acrylate (28):

26

Colorless oil. ½ꢃꢃ_D¼ ꢁ45:2 (c 1.04, CHCl₃). IR (neat) 1714,

1

1659, 1321, 1163 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 7.82 (d,

J ¼ 7:8 Hz, 2H), 7.35 (d, J ¼ 7:8 Hz, 2H), 6.43 (dd, J ¼ 15:7,

7.6 Hz, 1H), 6.04 (d, J ¼ 15:7 Hz, 1H), 3.38–3.31 (m, 1H),

2.85 (d, J ¼ 7:0 Hz, 1H), 2.46 (s, 3H), 2.27 (d, J ¼ 4:3 Hz,

1H), 1.45 (s, 9H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 164.3, 144.8,

140.3, 134.4, 129.7, 127.8, 127.1, 81.0, 38.6, 34.6, 28.1, 21.7.

HRMS (ESI) calcd for C₁₆H₂₁NNaO₄S ½M þ Naꢃ^þ346.1089,

found 346.1094.

syn-28a: Colorless oil. IR (neat) 3513, 3280, 1723, 1329, 1159

.

cm^ꢁ1

¹H NMR (270 MHz, CDCl₃) ꢁ 7.78 (d, J ¼ 8:4 Hz, 2H),

7.31–7.14 (m, 7H), 5.70 (dd, J ¼ 15:1, 8.4 Hz, 1H), 5.56 (dt,

J ¼ 15:1, 6.2 Hz, 1H), 4.81 (t, J ¼ 6:2 Hz, 1H), 3.91–3.79 (m,

1H), 3.55 (t, J ¼ 6:2 Hz, 2H), 2.89 (dd, J ¼ 8:4, 4.1 Hz, 1H),

2.85–2.55 (m, 2H), 2.41 (s, 3H), 1.79–1.55 (m, 2H), 1.41 (s,

9H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 172.2, 143.4, 141.6, 136.4,

130.2, 129.6, 128.3, 128.3, 127.6, 127.0, 125.8, 81.8, 70.7, 55.2,

45.1, 36.0, 31.9, 28.0, 21.6. HRMS (ESI) calcd for

C₂₅H₃₃NNaO₅S ½M þ Naꢃ^þ482.1977, found 482.1966.

Phenyl (2E)-3-[(2R)-1-Tosylaziridin-2-yl]acrylate (29):

25

Colorless oil. ½ꢃꢃ_D¼ ꢁ76:3 (c 1.18, CHCl₃). IR (neat) 1738,

1328, 1162 cm^ꢁ1

.

¹H NMR (270 MHz, CDCl₃) ꢁ 7.85 (d, J ¼

8:4 Hz, 2H), 7.39–7.34 (m, 4H), 7.23 (t, J ¼ 7:8 Hz, 1H), 7.08

(d, J ¼ 7:3 Hz, 2H), 6.77 (dd, J ¼ 15:7, 7.6 Hz, 1H), 6.33 (d, J ¼

15:7 Hz, 1H), 3.48–3.41 (m, 1H), 2.92 (d, J ¼ 7:0 Hz, 1H), 2.47

(s, 3H), 2.34 (d, J ¼ 4:3 Hz, 1H). ¹³C NMR (68 MHz, CDCl₃) ꢁ

163.5, 150.2, 145.0, 143.6, 134.4, 129.8, 129.3, 127.9, 125.9,

124.4, 121.3, 38.4, 34.9, 21.8. HRMS (ESI) calcd for

C₁₈H₁₇NNaO₄S ½M þ Naꢃ^þ366.0776, found 366.0782.

anti-28a: Colorless oil. IR (neat) 3504, 3280, 1723, 1329,

1

1158 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 7.72 (d, J ¼ 8:4 Hz,

2H), 7.30–7.14 (m, 7H), 5.62 (dd, J ¼ 15:7, 7.3 Hz, 1H), 5.54

(dt, J ¼ 15:4, 5.4 Hz, 1H), 4.62 (t, J ¼ 5:7 Hz, 1H), 3.74–3.65

(m, 1H), 3.54 (t, J ¼ 5:4 Hz, 2H), 2.96 (t, J ¼ 7:6 Hz, 1H),

2.90–2.55 (m, 2H), 2.42 (s, 3H), 1.79–1.55 (m, 2H), 1.42 (s,

9H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 172.0, 143.4, 141.6, 136.5,

129.6, 129.2, 128.6, 128.4, 128.3, 127.0, 125.8, 81.9, 71.9, 55.5,

45.0, 36.6, 31.9, 28.1, 21.6. HRMS (ESI) calcd for

C₂₅H₃₃NNaO₅S ½M þ Naꢃ^þ482.1977, found 482.1966.

2,6-Dimethylphenyl (2E)-3-[(2R)-1-Tosylaziridin-2-yl]acry-

16

late (30): Colorless oil. ½ꢃꢃ_D¼ ꢁ60:6 (c 1.03, CHCl₃). IR

(neat) 1736, 1329, 1163 cm^ꢁ^{1 1}H NMR (270 MHz, CDCl₃) ꢁ

.

7.86 (d, J ¼ 7:8 Hz, 2H), 7.37 (d, J ¼ 7:8 Hz, 2H), 7.05 (s,

3H), 6.81 (dd, J ¼ 15:7, 7.3 Hz, 1H), 6.39 (d, J ¼ 15:4 Hz,

1H), 3.52–3.41 (m, 1H), 2.91 (d, J ¼ 7:0 Hz, 1H), 2.46 (s, 3H),

2.34 (d, J ¼ 3:8 Hz, 1H), 2.11 (s, 6H). ¹³C NMR (68 MHz,

CDCl₃) ꢁ 162.8, 147.7, 145.0, 143.7, 134.3, 129.9, 129.8, 128.4,

127.9, 125.9, 123.9, 38.3, 35.0, 21.8, 16.4. HRMS (ESI) calcd

for C₂₀H₂₁NNaO₄S ½M þ Naꢃ^þ394.1089, found 394.1108.

Typical Procedure for Samarium(II) Iodide-Mediated Aldol

Reaction of ꢂ,ꢁ-Aziridinyl–ꢃ,ꢀ-Unsaturated Ester with Alde-

hyde. (Table 10, Entry 5). To a mixture of 2,6-dimethylphenyl

(2E)-3-[(2R)-1-tosylaziridin-2-yl]acrylate (30) (56.1 mg, 0.151

mmol) and 3-phenylpropanal (24.3 mg, 0.181 mmol) in THF (3

syn-29a: Colorless oil. IR (neat) 3505, 3286, 1752, 1327, 1160

cm^ꢁ1

.

¹H NMR (270 MHz, CDCl₃) ꢁ 7.74 (d, J ¼ 8:4 Hz, 2H),

7.40–7.17 (m, 10H), 7.00 (d, J ¼ 8:4 Hz, 2H), 5.84 (dd,

J ¼ 15:1, 8.9 Hz, 1H), 5.70 (dt, J ¼ 15:1, 5.7 Hz, 1H), 4.89 (t,

J ¼ 5:7 Hz, 1H), 4.10–3.95 (m, 1H), 3.61 (t, J ¼ 5:7 Hz, 2H),

3.24 (dd, J ¼ 8:6, 4.6 Hz, 1H), 2.91–2.60 (m, 3H), 2.40 (s, 3H),

1.95–1.63 (m, 2H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 171.2, 150.1,

143.5, 141.4, 136.4, 131.4, 129.7, 129.4, 128.4, 127.0, 126.4,

126.0, 125.9, 121.2, 70.8, 54.6, 44.9, 36.2, 31.9, 21.6. HRMS

(ESI) calcd for C₂₇H₂₉NNaO₅S ½M þ Naꢃ^þ502.1664, found

502.1654.

ꢂ

mL) at ꢁ78 C under an argon atmosphere was added a solution

of SmI₂in THF (0.1 M, 3.8 mL, 0.38 mmol). After the reaction

mixture was stirred for 30 min at ꢁ78 ^ꢂC, the reaction mixture

was quenched with saturated aqueous ammonium chloride and

was diluted with ethyl acetate. It was extracted with ethyl acetate,

and the organic layer was washed with brine and dried over anhy-

anti-29a: Colorless oil. IR (neat) 3507, 3285, 1753, 1327,

1

1160 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 7.73 (d, J ¼ 8:4 Hz,

2H), 7.40–7.10 (m, 10H), 7.01 (d, J ¼ 8:4 Hz, 2H), 5.73 (dd,

J ¼ 15:7, 7.6 Hz, 1H), 5.67 (dt, J ¼ 15:4, 5.4 Hz, 1H), 4.65 (t,

J ¼ 6:5 Hz, 1H), 3.95–3.80 (m, 1H), 3.59 (t, J ¼ 5:2 Hz, 2H),

Y. Ogawa et al.

Bull. Chem. Soc. Jpn., 78, No. 7 (2005) 1329

21

3.31 (t, J ¼ 7:6 Hz, 1H), 2.93–2.80 (m, 1H), 2.75–2.60 (m, 1H),

2.52 (brs, 1H), 2.40 (s, 3H), 1.91–1.61 (m, 2H). ¹³C NMR (68

MHz, CDCl₃) ꢁ 171.1, 150.1, 143.6, 141.4, 136.6, 130.6, 129.7,

129.4, 128.4, 128.4, 127.2, 127.0, 126.0, 125.9, 121.3, 71.8,

55.3, 44.9, 36.4, 31.9, 21.6. HRMS (ESI) calcd for

C₂₇H₂₉NNaO₅S ½M þ Naꢃ^þ502.1664, found 502.1657.

mg, 35%). Colorless oil. ½ꢃꢃ_D¼ ꢁ47:5 (c 1.16, CHCl₃). Color-

less oil. IR (neat) 1617, 1326, 1161 cm^ꢁ^{1 1}H NMR (270 MHz,

.

CDCl₃) ꢁ 7.83 (d, J ¼ 8:1 Hz, 2H), 7.34 (d, J ¼ 8:1 Hz, 2H),

6.59–6.44 (m, 2H), 3.44–3.27 (m, 5H), 2.87 (d, J ¼ 7:3 Hz,

1H), 2.45 (s, 3H), 2.28 (d, J ¼ 4:3 Hz, 1H), 1.15 (t, J ¼ 7:3 Hz,

3H), 1.12 (t, J ¼ 7:3 Hz, 3H). ¹³C NMR (68 MHz, CDCl₃) ꢁ

164.0, 144.7, 138.4, 134.5, 129.6, 127.7, 124.5, 42.2, 40.9, 39.3,

34.7, 21.7, 14.9, 13.0. HRMS (ESI) calcd for C₁₆H₂₃N₂O₃S

½M þ Hꢃ^þ323.1429, found 323.1451.

syn-30a: Colorless oil. IR (neat) 3516, 3286, 1748, 1327, 1160

cm^ꢁ1

.

¹H NMR (270 MHz, CDCl₃) ꢁ 7.74 (d, J ¼ 8:4 Hz, 2H),

7.33–7.16 (m, 7H), 7.04 (s, 3H), 5.89 (dd, J ¼ 15:4, 9.7 Hz,

1H), 5.76 (dt, J ¼ 15:1, 6.3 Hz, 1H), 4.68 (t, J ¼ 5:4 Hz, 1H),

4.13–4.04 (m, 1H), 3.62 (t, J ¼ 5:9 Hz, 2H), 3.31 (dd, J ¼ 9:2,

4.1 Hz, 1H), 2.88–2.80 (m, 1H), 2.76–2.62 (m, 1H), 2.40 (s,

3H), 2.06 (s, 6H), 1.85–1.65 (m, 2H). ¹³C NMR (68 MHz, CDCl₃)

ꢁ 170.5, 147.5, 143.5, 141.3, 136.4, 131.6, 129.8, 129.7, 128.5,

128.4, 128.3, 127.0, 126.5, 126.0, 125.9, 70.7, 54.5, 44.8, 36.3,

32.0, 21.6, 16.5. HRMS (ESI) calcd for C₂₉H₃₃NNaO₅S ½M þ

Naꢃ^þ530.1977, found 530.1988.

(2E)-1-Pyrrolidin-1-yl-3-[(2R)-1-tosylaziridin-2-yl]prope-

none (33). To a solution of crude (2R)-1-tosylaziridine-2-carbox-

ylic acid (420 mg, 1.57 mmol) in THF (20 mL) at 0 C under ar-

ꢂ

gon atmosphere was added Et₃N (428 mg, 4.23 mmol), pivaloyl

chloride (PivCl) (257 mg, 2.13 mmol). After 45 min, pyrrolidine

(223 mg, 3.13 mmol) was added to the reaction mixture, and it

was allowed to warm at room temperature. After the reaction mix-

ture was stirred for 1 h, it was quenched with H₂O. Then, it was

extracted with ethyl acetate, and the organic layer was washed

with brine and dried over anhydrous sodium sulfate. The crude

product was obtained after evaporation of the solvent under

reduced pressure, and puriﬁcation by column chromatography

(2E)-1-Phenyl-3-[(2R)-1-tosylaziridin-2-yl]propenone (31).

To a solution of methyl (2R)-1-tosylaziridine-2-carboxylate (500

ꢂ

mg, 1.96 mmol) in CH₂Cl₂(7 mL) at ꢁ78 C under argon atmo-

sphere was added a solution of DIBAL in toluene (1.1 M, 2.2 mL,

2.4 mmol). After the reaction mixture was stirred for 1 h, NH₄Cl

aq (1 mL) was added to it with stirring at ꢁ78 ^ꢂC, followed by 2-

(triphenylphosphoranylidene)acetophenone (820 mg, 2.4 mmol).

After the reaction mixture was stirred for 3 h, it was quenched

with 1 M HCl aq. Then, it was extracted with ethyl acetate, and

the organic layer was washed with brine and dried over anhydrous

sodium sulfate. The crude product was obtained after evaporation

of the solvent under reduced pressure, and puriﬁcation by column

chromatography aﬀorded propenone 31 (430 mg, 67%). Colorless

21

aﬀorded 33 (350 mg, 70%). Colorless oil. ½ꢃꢃ_D¼ ꢁ37:1 (c

0.83, CHCl₃). IR (neat) 1621, 1450, 1321, 1162 cm^ꢁ1. H NMR

1

(270 MHz, CDCl₃) ꢁ 7.82 (d, J ¼ 7:3 Hz, 2H), 7.34 (d, J ¼ 7:3

Hz, 2H), 6.53 (dd, J ¼ 15:1, 7.0 Hz, 1H), 6.40 (d, J ¼ 14:9 Hz,

1H), 3.52–3.43 (m, 4H), 3.35 (dt, J ¼ 4:3, 7.0 Hz, 1H), 2.85 (d,

J ¼ 7:0 Hz, 1H), 2.44 (s, 3H), 2.27 (d, J ¼ 4:3 Hz, 1H), 1.98–

1.82 (m, 4H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 163.0, 144.7,

138.1, 134.6, 129.7, 127.8, 125.6, 46.6, 46.0, 39.2, 34.9, 26.1,

24.3, 21.8. HRMS (ESI) calcd for C₁₆H₂₁N₂O₃S ½M þ Hꢃ^þ

321.1273, found 321.1250.

23

oil. ½ꢃꢃ_D¼ ꢁ53:0 (c 1.05, CHCl₃). IR (neat) 1624, 1320, 1158

cm^ꢁ1

.

¹H NMR (270 MHz, CDCl₃) ꢁ 7.89 (d, J ¼ 8:4 Hz, 2H),

3-[(2E)-3-((2R)-1-Tosylaziridin-2-yl)acryloyl]oxazolidin-2-

one (34). To a solution of crude (2R)-1-tosylaziridine-2-carbox-

ylic acid (260 mg, 0.973 mmol) in THF (9 mL) at 0 C under ar-

7.86 (d, J ¼ 8:1 Hz, 2H), 7.59 (t, J ¼ 7:3 Hz, 1H), 7.48 (t, J ¼

8:1 Hz, 2H), 7.36 (d, J ¼ 8:1 Hz, 2H), 7.19 (d, J ¼ 15:4, 1H),

6.66 (dd, J ¼ 15:4, 7.6 Hz, 1H), 3.47 (ddd, J ¼ 7:6, 7.0, 4.3

Hz, 1H), 2.93 (d, J ¼ 7:0 Hz, 1H), 2.44 (s, 3H), 2.35 (d, J ¼

4:3 Hz, 1H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 188.8, 144.8, 141.3,

136.8, 134.4, 133.1, 129.7, 128.5, 128.5, 128.4, 127.8, 39.1,

35.0, 21.7. HRMS (ESI) calcd for C₁₈H₁₇NNaO₃S ½M þ Naꢃ^þ

350.0827, found 350.0849.

ꢂ

gon atmosphere was added Et₃N (294 mg, 2.92 mmol), PivCl (176

mg, 1.46 mmol). After 45 min, LiCl (212 mg, 5.00 mmol) and ox-

azolidin-2-one (127 mg, 1.46 mmol) was added to the reaction

mixture, and it was allowed to warm at room temperature. After

the reaction mixture was stirred for 1 h, it was quenched with

H₂O. Then, it was extracted with ethyl acetate, and the organic

layer was washed with brine and dried over anhydrous sodium sul-

fate. The crude product was obtained after evaporation of the sol-

(2E)-N,N-Diethyl-3-[(2R)-1-tosylaziridin-2-yl]acrylamide

(32). To a solution of methyl (2E)-3-[(2R)-1-tosylaziridin-2-yl]-

acrylate (23) (300 mg, 1.78 mmol) in dioxane (2 mL)–MeOH (2

mL)–H₂O (1 mL) at 0 ^ꢂC was added LiOH (123 mg, 5.34 mmol).

After the reaction mixture was stirred for 4 h at room temperature,

the reaction mixture was quenched with saturated aqueous ammo-

nium chloride and was diluted with ethyl acetate. It was extracted

with ethyl acetate, and the organic layer was washed with brine

and dried over anhydrous sodium sulfate. After evaporation of

the solvent under reduced pressure, crude (2E)-3-[(2R)-1-tosyl-

aziridin-2-yl]acrylic acid was obtained. To a mixture of crude

(2R)-1-tosylaziridine-2-carboxylic acid (260 mg, 0.97 mmol),

vent under reduced pressure, and puriﬁcation by column chroma-

20

tography aﬀorded 34 (168 mg, 52%). Colorless oil. ½ꢃꢃ_D

¼

ꢁ34:6 (c 1.10, CHCl₃). IR (neat) 1777, 1685, 1388, 1162 cm^ꢁ1

.

¹H NMR (270 MHz, CDCl₃) ꢁ 7.82 (d, J ¼ 8:1 Hz, 2H), 7.54

(d, J ¼ 15:4 Hz, 1H), 7.35 (d, J ¼ 8:1 Hz, 2H), 6.66 (dd,

J ¼ 15:4, 8.1 Hz, 1H), 4.43 (t, J ¼ 8:1 Hz, 2H), 4.04 (t, J ¼ 8:1

Hz, 2H), 3.42 (ddd, J ¼ 8:1, 7.0, 4.3 Hz, 1H), 2.90 (d, J ¼ 7:0

Hz, 1H), 2.45 (s, 3H), 2.34 (d, J ¼ 4:3 Hz, 1H). ¹³C NMR (68

MHz, CDCl₃) ꢁ 163.6, 153.1, 144.8, 143.2, 134.3, 129.7, 127.8,

123.6, 62.1, 42.6, 39.1, 34.5, 21.7. HRMS (ESI) calcd for

C₁₅H₁₇N₂O₅S ½M þ Hꢃ^þ337.0858, found 337.0866.

ꢂ

Et₂NH (140 mg, 1.94 mmol) in CH₂Cl₂(5 mL) at 0 C under ar-

gon atmosphere was added 1-ethyl-3-(3-dimethylaminopropyl)-

carbodiimide hydrochloride (EDCI HCl) (205 mg, 1.07 mol). Af-

Typical Procedure for Samarium(II) Iodide-Mediated Aldol

Reaction of Unsaturated Aziridine with Aldehyde. (Table 11,

Entry 4). To a mixture of 3-[(2E)-3-((2R)-1-tosylaziridin-2-yl)-

acryloyl]oxazolidin-2-one (34) (22.0 mg, 0.066 mmol) and 3-

phenylpropanal (10.0 mg, 0.075 mmol) in THF (3 mL) at ꢁ78

^ꢂC under an argon atmosphere was added a solution of SmI₂in

THF (0.1 M, 1.6 mL, 0.16 mmol). After the reaction mixture

was stirred for 30 min at ꢁ78 ^ꢂC, the reaction mixture was

quenched with saturated aqueous ammonium chloride and was di-

ꢄ

ter the reaction mixture was stirred for 2 h at room temperature,

the reaction mixture was quenched with saturated aqueous ammo-

nium chloride and was diluted with ethyl acetate. It was extracted

with ethyl acetate, and the organic layer was washed with brine

and dried over anhydrous sodium sulfate. The crude product

was obtained after evaporation of the solvent under reduced pres-

sure, and puriﬁcation by column chromatography aﬀorded 32 (111

1330 Bull. Chem. Soc. Jpn., 78, No. 7 (2005)

SmI₂-Mediated Aldol Reactions of Acylaziridines

luted with ethyl acetate. It was extracted with ethyl acetate, and

the organic layer was washed with brine and dried over anhydrous

sodium sulfate. The crude product was obtained after evaporation

of the solvent under reduced pressure, and puriﬁcation by thin-

layer chromatography aﬀorded syn-34a (25.1 mg, 81%).

45.2, 38.9, 32.0, 26.0, 24.2, 21.6. HRMS (ESI) calcd for

C₂₅H₃₃N₂O₄S ½M þ Hꢃ^þ457.2161, found 457.2147.

anti-33a: Colorless oil. IR (neat) 3275, 3176, 1616, 1329,

1

1159 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 7.72 (d, J ¼ 8:1 Hz,

2H), 7.31–7.23 (m, 5H), 7.18 (d, J ¼ 8:1 Hz, 2H), 5.68 (dd,

J ¼ 15:7, 8.4 Hz, 1H), 5.53 (dt, J ¼ 15:7, 5.7 Hz, 1H), 4.88 (t,

J ¼ 5:2 Hz, 1H), 3.76–3.65 (m, 1H), 3.51 (t, J ¼ 5:4 Hz, 2H),

3.46–3.30 (m, 4H), 3.05 (t, J ¼ 5:9 Hz, 1H), 2.95–2.82 (m, 1H),

2.69–2.54 (m, 1H), 2.42 (s, 3H), 1.95–1.60 (m, 6H). ¹³C NMR

(68 MHz, CDCl₃) ꢁ 171.1, 143.4, 142.0, 136.5, 129.7, 129.6,

128.6, 128.4, 128.3, 127.0, 125.7, 72.9, 52.7, 46.5, 45.8, 45.1,

37.1, 32.2, 25.9, 24.2, 21.6. HRMS (ESI) calcd for C₂₅H₃₃N₂O₄S

½M þ Hꢃ^þ457.2161, found 457.2171.

syn-31a: Colorless oil. IR (neat) 3501, 3282, 1678, 1328, 1159

.

cm^ꢁ1

¹H NMR (270 MHz, CDCl₃) ꢁ 7.86 (d, J ¼ 7:3 Hz, 2H),

7.68 (d, J ¼ 8:1 Hz, 2H), 7.58 (t, J ¼ 7:3 Hz, 1H), 7.45 (t, J ¼

7:8 Hz, 2H), 7.43–7.12 (m, 7H), 5.76 (dd, J ¼ 15:7, 8.4 Hz,

1H), 5.64 (dt, J ¼ 15:9, 5.7 Hz, 1H), 4.62 (t, J ¼ 5:9 Hz, 1H),

4.10–3.92 (m, 2H), 3.53 (t, J ¼ 5:9 Hz, 2H), 3.39 (brs, 1H),

2.95–2.77 (m, 1H), 2.75–2.61 (m, 1H), 2.40 (s, 3H), 1.94–1.65

(m, 2H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 201.4, 143.5, 141.6,

136.5, 135.7, 133.7, 131.4, 129.6, 128.7, 128.5, 128.4, 128.3,

128.0, 127.0, 125.8, 71.0, 54.8, 45.2, 36.2, 32.1, 21.6. HRMS

(ESI) calcd for C₂₇H₂₉NNaO₄S ½M þ Naꢃ^þ486.1715, found

486.1705.

syn-34a: Colorless oil. IR (neat) 3511, 3278, 1777, 1695,

1389, 1160 cm^ꢁ1

.

¹H NMR (270 MHz, CDCl₃) ꢁ 7.71 (d, J ¼

8:1 Hz, 2H), 7.31–7.24 (m, 5H), 7.18 (d, J ¼ 8:1 Hz, 2H), 5.82

(dd, J ¼ 15:7, 9.2 Hz, 1H), 5.55 (dt, J ¼ 15:7, 5.7 Hz, 1H),

5.00 (t, J ¼ 5:9 Hz, 1H), 4.46 (dd, J ¼ 8:9, 5.7 Hz, 1H), 4.43–

4.37 (m, 2H), 4.08–3.90 (m, 3H), 3.54 (t, J ¼ 5:9 Hz, 1H), 3.50

(t, J ¼ 5:4 Hz, 1H), 3.36 (brs, 1H), 2.87–2.75 (m, 1H), 2.70–

2.57 (m, 1H), 2.42 (s, 3H), 1.85–1.60 (m, 2H). ¹³C NMR (68

MHz, CDCl₃) ꢁ 173.9, 152.9, 143.5, 141.5, 136.2, 131.1, 129.6,

128.4, 128.3, 127.0, 125.8, 125.6, 71.1, 62.1, 50.9, 44.9, 42.7,

36.1, 31.9, 21.6. HRMS (ESI) calcd for C₂₄H₂₈N₂NaO₆S ½M þ

Naꢃ^þ495.1566, found 495.1567.

anti-31a: Colorless oil. IR (neat) 3500, 3279, 1679, 1328,

1

1159 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 7.88 (d, J ¼ 7:3 Hz,

2H), 7.66 (d, J ¼ 8:4 Hz, 2H), 7.58 (t, J ¼ 7:6 Hz, 1H), 7.45 (t,

J ¼ 7:8 Hz, 2H), 7.27–7.09 (m, 7H), 5.66 (dd, J ¼ 15:9, 8.4

Hz, 1H), 5.54 (dt, J ¼ 15:7, 5.1 Hz, 1H), 4.54 (t, J ¼ 5:7 Hz,

1H), 4.10 (t, J ¼ 8:1 Hz, 1H), 4.05–3.90 (m, 1H), 3.49 (t, J ¼

5:7 Hz, 2H), 3.01–2.77 (m, 2H), 2.75–2.56 (m, 1H), 2.40 (s,

3H), 1.91–1.67 (m, 2H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 201.2,

143.5, 141.6, 136.5, 136.4, 133.6, 130.2, 129.6, 129.2, 128.6,

128.5, 128.4, 128.3, 126.9, 125.8, 72.6, 55.7, 45.0, 36.5, 32.0,

21.6. HRMS (ESI) calcd for C₂₇H₂₉NNaO₄S ½M þ Naꢃ^þ

486.1715, found 486.1719.

Typical Procedure for the Preparation of ꢂ,ꢁ-Aziridinyl–

ꢃ,ꢀ-Unsaturated Imide. To a solution of crude (2R)-1-tosyl-

aziridine-2-carboxylic acid (690 mg, 2.58 mmol) in THF (25

ꢂ

mL) at 0 C under argon atmosphere was added Et₃N (781 mg,

syn-32a: Colorless oil. IR (neat) 3280, 1615, 1329, 1160

.

7.72 mmol), PivCl (468 mg, 3.88 mmol). After 45 min, LiCl

(562 mg, 13.3 mmol) and oxazolidin-2-one (686 mg, 3.87 mmol)

was added to the reaction mixture, and it was allowed to warm at

room temperature. After the reaction mixture was stirred for 1 h, it

was quenched with H₂O. Then, it was extracted with ethyl acetate,

and the organic layer was washed with brine and dried over anhy-

drous sodium sulfate. The crude product was obtained after evap-

oration of the solvent under reduced pressure, and puriﬁcation by

column chromatography aﬀorded 35 (512 mg, 47%).

cm^ꢁ1

¹H NMR (270 MHz, CDCl₃) ꢁ 7.72 (d, J ¼ 8:1 Hz, 2H),

7.31–7.15 (m, 7H), 5.75 (dd, J ¼ 15:7, 8.9 Hz, 1H), 5.30 (dt,

J ¼ 15:7, 5.9 Hz, 1H), 4.80 (t, J ¼ 6:2 Hz, 1H), 3.75–3.60 (m,

1H), 3.54 (t, J ¼ 5:9 Hz, 2H), 3.45–3.09 (m, 4H), 3.05 (dd,

J ¼ 8:6, 2.4 Hz, 1H), 2.89–2.74 (m, 1H), 2.73–2.58 (m, 2H),

2.42 (s, 3H), 1.93–1.72 (m, 2H), 1.12 (t, J ¼ 7:0 Hz, 3H), 1.11

(t, J ¼ 7:0 Hz, 3H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 172.9, 143.4,

141.7, 136.4, 129.8, 129.7, 128.4, 128.3, 128.1, 127.0, 125.8,

71.2, 49.3, 45.2, 42.1, 40.5, 35.9, 32.1, 21.6, 14.7, 13.0. HRMS

(ESI) calcd for C₂₅H₃₅N₂O₄S ½M þ Hꢃ^þ459.2318, found

459.2301.

(4R)-4-Benzyl-3-[(2E)-3-((2R)-1-tosylaziridin-2-yl)acryloyl]-

22

oxazolidin-2-one (35): Colorless oil. ½ꢃꢃ_D¼ ꢁ67:3 (c 1.00,

CHCl₃). IR (neat) 1779, 1685, 1388, 1162 cm^ꢁ^{1 1}H NMR (270

.

anti-32a: Colorless oil. IR (neat) 3465, 3275, 1614, 1329,

1

MHz, CDCl₃) ꢁ 7.84 (d, J ¼ 8:1 Hz, 2H), 7.57 (d, J ¼ 15:1 Hz,

1H), 7.38–7.25 (m, 5H), 7.18 (d, J ¼ 6:5 Hz, 2H), 6.72 (dd,

J ¼ 15:7, 8.1 Hz, 1H), 4.73–4.64 (m, 1H), 4.25–4.14 (m, 2H),

3.44 (ddd, J ¼ 8:1, 7.3, 4.3 Hz, 1H), 3.28 (dd, J ¼ 13:2, 3.2

Hz, 1H), 2.93 (d, J ¼ 7:3 Hz, 1H), 2.77 (dd, J ¼ 13:5, 6.8 Hz,

1H), 2.45 (s, 3H), 2.36 (d, J ¼ 4:3 Hz, 1H). ¹³C NMR (68 MHz,

CDCl₃) ꢁ 163.4, 153.0, 144.8, 143.5, 134.9, 134.3, 129.7, 129.3,

128.8, 127.8, 127.3, 124.1, 66.2, 55.2, 39.1, 37.7, 34.5, 21.7.

HRMS (ESI) calcd for C₂₂H₂₂N₂NaO₅S ½M þ Naꢃ^þ449.1147,

found 449.1160.

1160 cm^ꢁ1. H NMR (270 MHz, CDCl₃) ꢁ 7.72 (d, J ¼ 8:1 Hz,

2H), 7.34–7.14 (m, 7H), 5.73 (dd, J ¼ 15:7, 8.1 Hz, 1H), 5.51

(dt, J ¼ 15:7, 5.9 Hz, 1H), 4.80 (t, J ¼ 6:5 Hz, 1H), 4.33 (dd,

J ¼ 8:1, 2.2 Hz, 1H), 3.51 (t, J ¼ 5:9 Hz, 2H), 3.45–3.15 (m,

4H), 3.14 (t, J ¼ 8:1 Hz, 1H), 2.94–2.81 (m, 1H), 2.72–2.57 (m,

2H), 2.42 (s, 3H), 1.75–1.65 (m, 2H), 1.11 (t, J ¼ 7:3 Hz, 3H),

1.10 (t, J ¼ 7:0 Hz, 3H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 172.1,

143.4, 141.9, 136.2, 130.7, 129.7, 128.4, 128.3, 128.2, 127.0,

125.8, 73.1, 50.1, 45.2, 42.1, 40.5, 34.4, 32.3, 21.6, 14.8, 13.1.

HRMS (ESI) calcd for C₂₅H₃₅N₂O₄S ½M þ Hꢃ^þ459.2318, found

459.2299.

(4R)-4-Benzyl-3-[(2E)-3-((2R,3S)-3-methyl-1-tosylaziridin-

21

2-yl)acryloyl]oxazolidin-2-one (36):

Colorless oil. ½ꢃꢃ_D

¼

syn-33a: Colorless oil. IR (neat) 3402, 3172, 1616, 1332, 1161

.

ꢁ87:5 (c 1.11, CHCl₃). IR (neat) 1780, 1684, 1390, 1161 cm^ꢁ1

.

cm^ꢁ1

¹H NMR (270 MHz, CDCl₃) ꢁ 7.72 (d, J ¼ 8:1 Hz, 2H),

¹H NMR (270 MHz, CDCl₃) ꢁ 7.83 (d, J ¼ 8:1 Hz, 2H), 7.53

(d, J ¼ 15:4 Hz, 1H), 7.37–7.15 (m, 7H), 6.83 (dd, J ¼ 15:4,

7.6 Hz, 1H), 4.75–4.61 (m, 1H), 4.30–4.14 (m, 2H), 3.48 (t, J ¼

7:3 Hz, 1H), 3.31 (d, J ¼ 12:5 Hz, 1H), 3.17 (dq, J ¼ 7:3, 5.9

Hz, 1H), 2.77 (dd, J ¼ 13:2, 9.5 Hz, 1H), 2.44 (s, 3H), 1.27 (d,

J ¼ 5:7 Hz, 1H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 163.4, 152.9,

144.5, 140.7, 134.9, 134.6, 129.6, 129.2, 128.8, 127.6, 127.2,

125.2, 66.2, 55.2, 43.9, 41.6, 37.7, 21.7, 12.6. HRMS (ESI) calcd

7.31–7.22 (m, 5H), 7.19 (d, J ¼ 8:1 Hz, 2H), 5.73 (dd,

J ¼ 15:4, 8.9 Hz, 1H), 5.55 (dt, J ¼ 15:7, 5.7 Hz, 1H), 5.01 (t,

J ¼ 6:2 Hz, 1H), 3.95–3.88 (m, 1H), 3.54 (t, J ¼ 5:9 Hz, 2H),

3.53–3.33 (m, 4H), 2.95 (d, J ¼ 8:6 Hz, 1H), 2.89–2.75 (m,

1H), 2.73–2.57 (m, 1H), 2.42 (s, 3H), 2.01–1.60 (m, 6H).

¹³C NMR (68 MHz, CDCl₃) ꢁ 171.8, 143.4, 141.8, 136.4, 130.2,

129.6, 128.4, 128.2, 127.2, 127.0, 125.7, 70.6, 51.7, 46.5, 45.9,

Y. Ogawa et al.

Bull. Chem. Soc. Jpn., 78, No. 7 (2005) 1331

for C₂₃H₂₄N₂NaO₅S ½M þ Naꢃ^þ463.1304, found 463.1315.

Typical Procedure for Samarium(II) Iodide-Mediated Aldol

Reaction of Unsaturated Aziridine with Aldehyde. (Table 12,

Entry 1). To a mixture of (4R)-4-Benzyl-3-[(2E)-3-((2R)-1-

tosylaziridin-2-yl)acryloyl]oxazolidin-2-one (35) (43.0 mg, 0.098

J ¼ 13:5, 3.2 Hz, 1H), 2.76 (dd, J ¼ 13:2, 9.7 Hz, 1H), 2.47 (s,

3H), 2.03–1.93 (m, 1H), 1.81–1.50 (m, 4H), 1.41–0.95 (m, 6H).

¹³C NMR (68 MHz, CDCl₃) ꢁ 173.9, 152.7, 143.4, 136.3, 134.9,

130.7, 129.6, 129.2, 128.9, 127.3, 127.0, 126.6, 75.7, 66.2, 55.3,

48.1, 45.1, 40.5, 38.0, 28.9, 28.7, 26.3, 26.0, 25.9, 21.6. HRMS

(ESI) calcd for C₂₉H₃₆N₂NaO₆S ½M þ Naꢃ^þ563.2192, found

563.2204.

mmol) and 3-phenylpropanal (14.5 mg, 0.11 mmol) in THF (3

ꢂ

mL) at ꢁ78 C under an argon atmosphere was added a solution

18

of SmI₂in THF (0.1 M, 2.40 mL, 0.24 mmol). After the reaction

mixture was stirred for 30 min at ꢁ78 ^ꢂC, the reaction mixture

was quenched with saturated aqueous ammonium chloride and

was diluted with ethyl acetate. It was extracted with ethyl acetate,

and the organic layer was washed with brine and dried over anhy-

drous sodium sulfate. The crude product was obtained after evap-

oration of the solvent under reduced pressure, and puriﬁcation by

thin-layer chromatography aﬀorded syn-35a (51.3 mg, 93%).

syn-36a: Colorless oil. ½ꢃꢃ_D¼ ꢁ84:9 (c 1.05, CHCl₃). IR

1

(neat) 3510, 3282, 1779, 1696, 1389, 1161 cm^ꢁ1. H NMR (270

MHz, CDCl₃) ꢁ 7.72 (d, J ¼ 8:1 Hz, 2H), 7.31–7.15 (m, 12H),

5.70 (dd, J ¼ 15:7, 8.1 Hz, 1H), 5.60 (dt, J ¼ 15:7, 5.7 Hz,

1H), 4.81 (d, J ¼ 6:5 Hz, 1H), 4.73–4.58 (m, 1H), 4.44 (dd,

J ¼ 8:1, 4.1 Hz, 1H), 4.27–4.06 (m, 2H), 4.05–3.93 (m, 1H),

3.75–3.62 (m, 1H), 3.28 (dd, J ¼ 13:5, 3.2 Hz, 1H), 3.21 (d, J ¼

2:4 Hz, 1H), 2.94–2.60 (m, 3H), 2.41 (s, 3H), 1.93–1.65 (m, 2H),

1.14 (d, J ¼ 6:8 Hz, 3H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 173.5,

152.9, 143.3, 141.7, 137.8, 137.1, 135.0, 129.7, 129.2, 128.8,

128.4, 128.3, 128.2, 127.0, 125.7, 123.7, 71.1, 66.2, 55.5, 51.3,

51.0, 38.0, 35.9, 31.9, 21.8, 21.6. HRMS (ESI) calcd for

C₃₂H₃₆N₂NaO₆S ½M þ Naꢃ^þ599.2192, found 599.2201.

22

syn-35a: Colorless oil. ½ꢃꢃ_D¼ ꢁ43:1 (c 1.08, CHCl₃). IR

1

(neat) 3509, 3280, 1780, 1697, 1390, 1160 cm^ꢁ1. H NMR (270

MHz, CDCl₃) ꢁ 7.71 (d, J ¼ 8:1 Hz, 2H), 7.30–7.15 (m, 12H),

5.82 (dd, J ¼ 15:7, 8.6 Hz, 1H), 5.65 (dt, J ¼ 15:7, 5.7 Hz,

1H), 4.88 (t, J ¼ 6:2 Hz, 1H), 4.68–4.58 (m, 1H), 4.46 (dd,

J ¼ 8:9, 3.2 Hz, 1H), 4.25–4.08 (m, 2H), 4.03–3.92 (m, 1H),

3.53 (t, J ¼ 5:7 Hz, 2H), 3.26 (dd, J ¼ 13:2, 3.2 Hz, 1H), 3.19

(d, J ¼ 2:4 Hz, 1H), 2.90–2.57 (m, 3H), 2.41 (s, 3H), 1.85–1.60

(m, 2H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 173.6, 152.8, 143.4,

141.5, 136.3, 134.9, 131.4, 129.6, 129.2, 128.9, 128.4, 128.3,

127.3, 127.0, 126.1, 125.8, 71.0, 66.2, 55.4, 50.9, 45.0, 38.0,

35.9, 31.9, 21.6. HRMS (ESI) calcd for C₃₁H₃₄N₂NaO₆S

½M þ Naꢃ^þ585.2035, found 585.2064.

16

syn-36b: Colorless oil. ½ꢃꢃ_D¼ ꢁ133 (c 0.99, CHCl₃). IR

1

(neat) 3520, 3280, 1780, 1695, 1389, 1160 cm^ꢁ1. H NMR (270

MHz, CDCl₃) ꢁ 7.40 (d, J ¼ 8:1 Hz, 2H), 7.38–7.19 (m, 7H),

5.70 (dd, J ¼ 15:7, 8.6 Hz, 1H), 5.66–5.59 (m, 1H), 4.71–4.60

(m, 3H), 4.24 (t, J ¼ 8:4 Hz, 1H), 4.14 (dd, J ¼ 8:4, 1.6 Hz,

1H), 3.81–3.70 (m, 1H), 3.69–3.60 (m, 1H), 3.31 (dd, J ¼ 13:0,

3.0 Hz, 1H), 2.94 (d, J ¼ 2:4 Hz, 1H), 2.75 (dd, J ¼ 13:2, 10.0

Hz, 1H), 2.43 (s, 3H), 1.69–1.50 (m, 1H), 1.15 (d, J ¼ 6:8 Hz,

3H), 0.99 (d, J ¼ 6:5 Hz, 3H), 0.92 (d, J ¼ 6:5 Hz, 3H). ¹³C NMR

(68 MHz, CDCl₃) ꢁ 173.8, 152.8, 143.3, 137.3, 137.2, 135.0,

129.6, 129.2, 128.9, 127.3, 127.0, 124.0, 76.6, 66.2, 55.4, 51.3,

48.5, 38.1, 31.1, 21.9, 21.6, 19.3, 18.3. HRMS (ESI) calcd for

C₂₇H₃₄N₂NaO₆S ½M þ Naꢃ^þ537.2035, found 537.2022.

15

syn-35b: Colorless oil. ½ꢃꢃ_D¼ ꢁ61:3 (c 1.12, CHCl₃). IR

1

(neat) 3519, 3279, 1779, 1697, 1212, 1160 cm^ꢁ1. H NMR (270

MHz, CDCl₃) ꢁ 7.73 (d, J ¼ 8:1 Hz, 2H), 7.36–7.17 (m, 7H),

5.79 (dd, J ¼ 15:9, 8.6 Hz, 1H), 5.67 (dt, J ¼ 15:4, 5.4 Hz,

1H), 4.91 (t, J ¼ 5:7 Hz, 1H), 4.69–4.60 (m, 1H), 4.48 (dd,

J ¼ 8:6, 3.5 Hz, 1H), 4.22 (t, J ¼ 8:4 Hz, 1H), 4.15 (dd,

J ¼ 8:9, 2.2 Hz, 1H), 3.95–3.87 (m, 1H), 3.54 (t, J ¼ 5:4 Hz,

2H), 3.29 (dd, J ¼ 13:2, 3.2 Hz, 1H), 3.01 (brs, 1H), 2.76 (dd,

J ¼ 13:0, 9.5 Hz, 1H), 2.43 (s, 3H), 1.44 (dq, J ¼ 5:9, 7.3 Hz,

2H), 0.95 (t, J ¼ 7:3 Hz, 3H). ¹³C NMR (68 MHz, CDCl₃) ꢁ

173.6, 152.8, 143.4, 136.3, 134.9, 131.1, 129.6, 129.2, 128.9,

127.3, 127.0, 126.4, 73.2, 66.2, 55.4, 50.6, 45.0, 38.0, 27.2,

21.6, 10.2. HRMS (ESI) calcd for C₂₅H₃₀N₂NaO₆S ½M þ Naꢃ^þ

509.1722, found 509.1747.

21

37: Colorless oil. ½ꢃꢃ_D¼ ꢁ35:5 (c 1.00, CHCl₃). IR (neat)

3264, 1782, 1689, 1388, 1159 cm^ꢁ1. ¹H NMR (270 MHz, CDCl₃)

ꢁ 7.74 (d, J ¼ 8:4 Hz, 2H), 7.37–7.24 (m, 5H), 7.18 (d, J ¼ 6:5

Hz, 2H), 5.79 (dt, J ¼ 15:4, 6.8 Hz, 1H), 5.55 (dt, J ¼ 15:4, 6.2

Hz, 1H), 4.69–4.54 (m, 2H), 4.26–4.17 (m, 2H), 3.63 (d, J ¼

6:8 Hz, 2H), 3.60 (t, J ¼ 5:9 Hz, 2H), 3.27 (dd, J ¼ 13:5, 3.2

Hz, 1H), 2.75 (dd, J ¼ 13:2, 9.8 Hz, 1H), 2.43 (s, 3H). ¹³C NMR

(68 MHz, CDCl₃) ꢁ 170.6, 153.2, 143.4, 136.7, 134.9, 129.6,

129.2, 128.9, 127.3, 127.0, 125.3, 66.3, 55.1, 45.1, 38.7, 37.8,

21.6. HRMS (ESI) calcd for C₂₂H₂₄N₂NaO₅S ½M þ Naꢃ^þ

451.1304, found 451.1319.

23

syn-35c: Colorless oil. ½ꢃꢃ_D¼ ꢁ58:5 (c 1.18, CHCl₃). IR

1

(neat) 3521, 3277, 1780, 1695, 1389, 1160 cm^ꢁ1. H NMR (270

MHz, CDCl₃) ꢁ 7.72 (d, J ¼ 8:1 Hz, 2H), 7.36–7.17 (m, 7H),

5.79 (dd, J ¼ 15:4, 8.6 Hz, 1H), 5.68 (dt, J ¼ 15:7, 5.4 Hz,

1H), 4.84 (t, J ¼ 5:9 Hz, 1H), 4.68 (dd, J ¼ 8:6, 3.5 Hz, 1H),

4.67–4.60 (m, 1H), 4.23 (t, J ¼ 8:9 Hz, 1H), 4.15 (dd, J ¼ 8:9,

2.4 Hz, 1H), 3.67–3.57 (m, 1H), 3.55 (t, J ¼ 5:4 Hz, 2H), 3.28

(dd, J ¼ 13:2, 3.2 Hz, 1H), 2.96 (d, J ¼ 3:2 Hz, 1H), 2.76 (dd,

J ¼ 13:0, 9.7 Hz, 1H), 2.43 (s, 3H), 1.65–1.52 (m, 1H), 0.99 (d,

J ¼ 6:8 Hz, 3H), 0.90 (d, J ¼ 6:5 Hz, 3H). ¹³C NMR (68 MHz,

CDCl₃) ꢁ 173.9, 152.7, 143.4, 136.4, 134.9, 130.9, 129.6, 129.2,

128.9, 127.3, 127.1, 126.5, 76.7, 66.2, 55.3, 48.5, 45.1, 38.1,

31.2, 21.6, 19.0, 18.5. HRMS (ESI) calcd for C₂₆H₃₂N₂NaO₆S

½M þ Naꢃ^þ523.1879, found 523.1886.

(4S)-4-Benzyl-3-[(2E)-3-((2R,3S)-3-methyl-1-tosylaziridin-2-

17

yl)acryloyl]oxazolidin-2-one (38):

Colorless oil. ½ꢃꢃ_D

¼

ꢁ17:5 (c 1.02, CHCl₃). IR (neat) 1781, 1684, 1389, 1161 cm^ꢁ1

.

¹H NMR (270 MHz, CDCl₃) ꢁ 7.84 (d, J ¼ 8:4 Hz, 2H), 7.53

(d, J ¼ 15:1 Hz, 1H), 7.37–7.15 (m, 7H), 6.83 (dd, J ¼ 15:7,

7.3 Hz, 1H), 4.73–4.63 (m, 1H), 4.38–4.13 (m, 2H), 3.48 (t, J ¼

7:6 Hz, 1H), 3.30 (dd, J ¼ 13:8, 3.2 Hz, 1H), 3.17 (dq, J ¼ 7:3,

5.9 Hz, 1H), 2.77 (dd, J ¼ 13:2, 9.5 Hz, 1H), 2.44 (s, 3H), 1.27

(d, J ¼ 5:9 Hz, 1H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 163.4,

152.9, 144.5, 140.8, 134.9, 134.7, 129.7, 129.2, 128.8, 127.6,

127.2, 125.2, 66.2, 55.2, 43.9, 41.7, 37.7, 21.7, 12.6. HRMS

(ESI) calcd for C₂₃H₂₄N₂NaO₅S ½M þ Naꢃ^þ463.1304, found

463.1308.

19

syn-35d: Colorless oil. ½ꢃꢃ_D¼ ꢁ42:7 (c 1.03, CHCl₃). IR

23

1

(neat) 3522, 3276, 1780, 1696, 1212, 1160 cm^ꢁ1. H NMR (270

syn-38a: Colorless oil. ½ꢃꢃ_D¼ ꢁ4:90 (c 1.01, CHCl₃). IR

1

MHz, CDCl₃) ꢁ 7.73 (d, J ¼ 8:1 Hz, 2H), 7.35–7.17 (m, 7H),

5.79 (dd, J ¼ 15:9, 8.6 Hz, 1H), 5.66 (dt, J ¼ 15:7, 5.1 Hz,

1H), 4.88 (t, J ¼ 5:9 Hz, 1H), 4.72–4.60 (m, 2H), 4.27–4.05 (m,

2H), 3.75–3.62 (m, 1H), 3.54 (t, J ¼ 5:9 Hz, 2H), 3.27 (dd,

(neat) 3517, 3275, 1779, 1697, 1389, 1160 cm^ꢁ1. H NMR (270

MHz, CDCl₃) ꢁ 7.69 (d, J ¼ 8:1 Hz, 2H), 7.32–7.16 (m, 12H),

5.77–5.53 (m, 2H), 4.69 (d, J ¼ 6:2 Hz, 1H), 4.67–4.58 (m,

1H), 4.55–4.45 (m, 1H), 4.25 (t, J ¼ 8:1 Hz, 1H), 4.12 (d, J ¼

1332 Bull. Chem. Soc. Jpn., 78, No. 7 (2005)

SmI₂-Mediated Aldol Reactions of Acylaziridines

1747, 1162 cm^ꢁ1

¹H NMR (270 MHz, CDCl₃) ꢁ 7.71 (d, J ¼

9:2 Hz, 1H), 4.05–3.98 (m, 1H), 3.77–3.65 (m, 1H), 3.27 (dd,

J ¼ 13:5, 3.2 Hz, 1H), 3.19 (brs, 1H), 2.90–2.58 (m, 3H), 2.40

(s, 3H), 1.78–1.54 (m, 2H), 1.14 (d, J ¼ 6:3 Hz, 3H). ¹³C NMR

(68 MHz, CDCl₃) ꢁ 173.7, 152.8, 143.3, 141.6, 137.5, 135.0,

129.6, 129.2, 128.8, 128.4, 128.3, 127.2, 127.0, 126.2, 125.8,

123.8, 70.8, 66.2, 55.6, 51.3, 50.6, 38.0, 35.9, 31.9, 21.6, 21.6.

HRMS (ESI) calcd for C₃₂H₃₆N₂NaO₆S ½M þ Naꢃ^þ599.2192,

found 599.2167.

.

8:1 Hz, 2H), 7.55–4.48 (m, 2H), 7.45–7.37 (m, 3H), 7.34–7.15

(m, 5H), 7.09 (d, J ¼ 6:8 Hz, 2H), 5.50 (dd, J ¼ 15:7, 7.8 Hz,

1H), 5.45 (dt, J ¼ 15:7, 5.4 Hz, 1H), 5.44–5.37 (m, 1H), 4.34

(t, J ¼ 6:2 Hz, 1H), 3.64 (s, 3H), 3.56–3.43 (m, 5H), 3.25 (dd,

J ¼ 8:4, 5.7 Hz, 1H), 2.66–2.45 (m, 2H), 2.42 (s, 3H), 2.03–

1.75 (m, 2H). HRMS (ESI) calcd for C₃₂H₃₄F₃NNaO₇S ½M þ

Naꢃ^þ656.1906, found 656.1885.

22

syn-38b: Colorless oil. ½ꢃꢃ_D¼ ꢁ2:42 (c 0.96, CHCl₃). IR

Carboxylic Acid 41. To a _ꢂsolution of syn-35a (9.0 mg, 0.022

mmol) in dioxane (1 mL) at 0 C was added 30% H₂O₂aq (0.03

mL, 0.256 mmol) and LiOH (1.5 mg, 0.065 mmol). After the re-

action mixture was stirred for 3 h, the reaction mixture was

quenched with Na₂SO₃aq. The reaction mixture was made acidic

with 5% HCl aq and extracted with ether, and the organic layer

was washed with brine and dried over anhydrous sodium sulfate.

The crude product was obtained after evaporation of the solvent

under reduced pressure, and puriﬁcation by thin-layer chromatog-

raphy aﬀorded carboxylic acid 41 (7.0 mg, 80%). Colorless oil.

(neat) 3527, 3276, 1779, 1696, 1388, 1160 cm^ꢁ1. H NMR (270

1

MHz, CDCl₃) ꢁ 7.71 (d, J ¼ 8:1 Hz, 2H), 7.37–7.18 (m, 7H),

5.73–5.60 (m, 2H), 4.73–4.60 (m, 3H), 4.26 (t, J ¼ 8:6 Hz, 1H),

4.14 (dd, J ¼ 8:1, 1.6 Hz, 1H), 3.80–3.68 (m, 1H), 3.67–3.58

(m, 1H), 3.29 (dd, J ¼ 13:2, 3.2 Hz, 1H), 2.95 (d, J ¼ 3:2 Hz,

1H), 2.76 (dd, J ¼ 13:2, 9.7 Hz, 1H), 2.42 (s, 3H), 1.61–1.48

(m, 1H), 1.15 (d, J ¼ 6:5 Hz, 3H), 0.99 (d, J ¼ 6:8 Hz, 3H),

0.90 (d, J ¼ 6:5 Hz, 3H). ¹³C NMR (68 MHz, CDCl₃) ꢁ 174.0,

152.9, 143.4, 137.2, 137.1, 135.0, 129.6, 129.3, 128.8, 127.3,

127.1, 124.1, 76.5, 66.2, 55.5, 51.3, 48.3, 38.1, 31.3, 21.7, 21.6,

19.0, 18.4. HRMS (ESI) calcd for C₂₇H₃₅N₂O₆S ½M þ Hꢃ^þ

515.2216, found 515.2212.

23

½ꢃꢃ_D¼ ꢁ22:6 (c 0.40, CHCl₃). IR (neat) 3283, 1581, 1159

cm^ꢁ1

.

¹H NMR (270 MHz, CD₃OD) ꢁ 7.71 (d, J ¼ 8:1 Hz,

2H), 7.33 (d, J ¼ 8:1 Hz, 2H), 7.23–7.12 (m, 5H), 5.73 (dd,

J ¼ 15:4, 9.7 Hz, 1H), 5.57 (dt, J ¼ 15:1, 5.9 Hz, 1H), 3.83–

3.71 (m, 1H), 3.44 (d, J ¼ 5:9 Hz, 2H), 2.88–2.70 (m, 2H),

2.66–2.50 (m, 1H), 2.41 (s, 3H), 1.77–1.53 (m, 2H). ¹³C NMR

(68 MHz, CD₃OD) ꢁ 171.4, 145.2, 144.2, 139.5, 132.4, 131.4,

130.2, 130.0, 129.9, 128.8, 127.3, 73.6, 59.9, 48.7, 47.0, 34.0,

22.3. HRMS (ESI) calcd for C₂₁H₂₅NNaO₅S ½M þ Naꢃ^þ

426.1315, found 426.1366.

(ꢀ)-syn-23e. To a solution of syn-35a (9.6 mg, 0.017 mmol)

in MeOH (1 mL) at 0 ^ꢂC was added NaOMe (0.1 mL, 28% in

MeOH). After the reaction mixture was stirred for 1 h at 0 ^ꢂC,

the reaction mixture was quenched with saturated aqueous ammo-

nium chloride and was diluted with ethyl acetate. It was extracted

with ethyl acetate, and the organic layer was washed with brine

and dried over anhydrous sodium sulfate. The crude product

was obtained after evaporation of the solvent under reduced pres-

sure, and puriﬁcation by thin-layer chromatography aﬀorded (ꢁ)-

Diol 42. To a solution of syn-35a (8.2 mg, 0.0196 mmol) in

EtOH (1 mL) at 0 ^ꢂC was added LiBH₄(2.0 M in THF, 0.1

mL, 0.2 mmol). After the reaction mixture was stirred for 2 h,

the reaction mixture was quenched with saturated NH₄Cl aq. It

was extracted with CH₂Cl₂, and the organic layer was washed

with brine and dried over anhydrous sodium sulfate. The crude

product was obtained after evaporation of the solvent under

reduced pressure, and puriﬁcation by thin-layer chromatography

21

syn-23e (6.1 mg, 85%). Colorless oil. ½ꢃꢃ_D¼ ꢁ27:0 (c 0.26,

CHCl₃).

(þ)-MTPA Ester 39. To a solution of (ꢁ)-syn-23e (3.4 mg,

ꢂ

0.0081 mmol) in pyridine (1 mL) at 0 C under an argon atmo-

sphere was added DMAP (2 mg, 0.016 mmol) and (þ)-MTPA-

Cl (10 mg, 0.040 mmol). After the reaction mixture was stirred

for 10 h at room temperature, the reaction mixture was quenched

with H₂O and was diluted with ethyl acetate. It was extracted with

ethyl acetate, and the organic layer was washed with brine and

dried over anhydrous sodium sulfate. The crude product was ob-

tained after evaporation of the solvent under reduced pressure,

and puriﬁcation by thin-layer chromatography aﬀorded 39 (2.6

23

aﬀorded diol 42 (5.7 mg, 75%). Colorless oil. ½ꢃꢃ_D¼ ꢁ7:9 (c

1

0.15, CHCl₃). IR (neat) 3478, 3294, 1324, 1158 cm^ꢁ1. H NMR

(270 MHz, CDCl₃) ꢁ 7.74 (d, J ¼ 8:4 Hz, 2H), 7.31–7.15 (m,

7H), 5.74 (dd, J ¼ 15:4, 8.4 Hz, 1H), 5.53 (dt, J ¼ 15:7, 5.9

Hz, 1H), 4.80 (brs, 1H), 3.83–3.75 (m, 1H), 3.72 (d, J ¼ 5:4

Hz, 2H), 3.56 (brs, 2H), 2.84–2.70 (m, 1H), 2.68–2.55 (m, 1H),

2.41 (s, 3H), 2.23–2.12 (m, 1H), 1.78–1.51 (m, 2H). ¹³C NMR

(68 MHz, CDCl₃) ꢁ 143.5, 141.6, 136.5, 129.9, 129.7, 129.0,

128.3, 127.0, 125.8, 72.5, 65.3, 49.3, 45.2, 37.0, 32.2, 21.6. HRMS

(ESI) calcd for C₂₁H₂₇NNaO₄S ½M þ Naꢃ^þ412.1559, found

412.1532.

19

mg, 57%). Colorless oil. ½ꢃꢃ_D¼ þ17:4 (c 0.17, CHCl₃). IR

(neat) 3289, 1747, 1163 cm^ꢁ^{1 1}H NMR (270 MHz, CDCl₃) ꢁ

.

7.71 (d, J ¼ 8:1 Hz, 2H), 7.54 (brs, 2H), 7.42 (brs, 3H), 7.29–

7.15 (m, 5H), 7.03 (d, J ¼ 6:8 Hz, 2H), 5.60 (dd, J ¼ 15:1, 8.4

Hz, 1H), 5.49 (dt, J ¼ 15:1, 5.1 Hz, 1H), 5.44–5.38 (m, 1H),

4.34 (t, J ¼ 5:9 Hz, 1H), 3.65 (s, 3H), 3.54 (s, 3H), 3.50 (t, J ¼

5:4 Hz, 2H), 3.30–3.23 (m, 1H), 2.50–2.43 (m, 2H), 2.42 (s,

3H), 1.95–1.70 (m, 2H). HRMS (ESI) calcd for C₃₂H₃₄F₃NNaO₇S

½M þ Naꢃ^þ656.1906, found 656.1905.

This study was supported in part a the Grant of the 21st

Century COE Program, Ministry of Education, Culture, Sports,

Science and Technology (MEXT).

(ꢀ)-MTPA Ester 40. To a solution of (ꢁ)-23c (5.3 mg, 0.013

mmol) in pyridine (1 mL) at 0 ^ꢂC under an argon atmosphere was

added DMAP (2.0 mg, 0.016 mmol) and (ꢁ)-MTPA-Cl (10 mg,

0.040 mmol). After the reaction mixture was stirred for 10 h at

room temperature, the reaction mixture was quenched with H₂O

and was diluted with ethyl acetate. It was extracted with ethyl ace-

tate, and the organic layer was washed with brine and dried over

anhydrous sodium sulfate. The crude product was obtained after

evaporation of the solvent under reduced pressure, and puriﬁca-

tion by thin-layer chromatography aﬀorded 40 (5.5 mg, 78%).

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Article Doi

Highly stereoselective samarium(II) iodide-mediated aldol reactions of acylaziridines with aldehydes

DOI: 10.1246/bcsj.78.1309

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Article abstract of DOI:10.1246/bcsj.78.1309

Full text of DOI:10.1246/bcsj.78.1309

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