Diastereoselective allylation of N-glyoxyloyl-(2R)-bornane-10,2-sultam and (1R)-8-phenylmenthyl glyoxylate: Synthesis of (2S,4S)-2-hydroxy-4-hydroxymethyl- 4-butanolide

Article abstract of DOI:10.1016/j.tetasy.2004.10.025

The diastereoselective addition of allylsilanes and allylstannanes to N-glyoxyloyl-(2R)-bornane-10,2-sultam 1 and (1R)-8-phenylmenthyl glyoxylate 7 in the presence of Lewis acids has been studied. We obtained diastereoselectivities up to 84% and 94% for the allylation of 2 and 7, respectively. The application of the allylation products of 1 or 2 in the synthesis of 4-butanolides, for example (2S,4S)-2-hydroxy-4-hydroxymethyl-4- butanolide 13 is presented.

Full text of DOI:10.1016/j.tetasy.2004.10.025

Tetrahedron:
Asymmetry
Tetrahedron: Asymmetry 15 (2004) 3869–3878
Diastereoselective allylation of N-glyoxyloyl-
(2R)-bornane-10,2-sultam and (1R)-8-phenylmenthyl glyoxylate:
synthesis of (2S,4S)-2-hydroxy-4-hydroxymethyl-4-butanolide
Katarzyna Kiegiel,a Tomasz Bałakier,a Piotr Kwiatkowskib and Janusz Jurczaka,b,
*
aDepartment of Chemistry, Warsaw University, 02-093 Warsaw, Poland
bInstitute of Organic Chemistry, Polish Academy of Sciences, 01-224 Warsaw, Poland
Received 1 September 2004; accepted 25 October 2004
Abstract—The diastereoselective addition of allylsilanes and allylstannanes to N-glyoxyloyl-(2R)-bornane-10,2-sultam 1 and (1R)-8-
phenylmenthyl glyoxylate 7 in the presence of Lewis acids has been studied. We obtained diastereoselectivities up to 84% and 94%
for the allylation of 2 and 7, respectively. The application of the allylation products of 1 or 2 in the synthesis of 4-butanolides, for
example (2S,4S)-2-hydroxy-4-hydroxymethyl-4-butanolide 13 is presented.
ꢀ 2004 Elsevier Ltd. All rights reserved.
1. Introduction
It has been found that (2S,4S)-2-hydroxy-4-hydroxy-
methyl-4-butanolide is responsible for the elicitation of
food intake in mammals.10 Its (2R,4R)-enantiomer has
been used as a starting material in the synthesis of the
A-ring of a vitamin D analog.11 2-Hydroxy-4-hydroxy-
methyl-4-butanolides are synthesized usually via degra-
dation of appropriate sugars12 or using enzymatic
procedures13 and others.14
Chiral a-hydroxy-c,d-unsaturated esters or amides are
important building blocks in organic synthesis and
many various synthetic intermediates can be readily pre-
pared from these compounds.1,2 The efficient methods
for synthesis of a-hydroxy-c,d-unsaturated derivatives
of carboxylic acids are the ene reaction,3 the glycolate
enolate allylation,4 and the nucleophilic addition of ally-
lic reagents to chiral glyoxylates5 or to chiral glyoxy-
mides.6 There are also other known stereoselective
methods for such allylations including an enantioselec-
tive catalytic approach7 or applying chiral allylating
reagents8 to alkyl glyoxylates. One of the potential
applications of this methodology seems to be the dia-
stereoselective synthesis of chiral 2,4-disubstituted-4-
butanolides.
Herein, we report the extended studies on the diastereo-
selective synthesis of 2-hydroxypent-4-enoic acid deriva-
tives using the asymmetric addition of allylic reagents to
N-glyoxyloyl-(2R)-bornane-10,2-sultam 1 or its hemi-
acetal 215 (Scheme 1), followed by the preparation of
(2S,4S)-2-hydroxy-4-hydroxymethyl-4-butanolide. For
comparison we also studied allylation reaction of 8-phen-
ylmenthyl glyoxylate.16
Chiral 4-butanolides form an important and interesting
groupof biologically active compounds, which could
also be applied as synthetically useful chiral building
blocks.9 Among them, 2-hydroxy-4-hydroxymethyl-4-
butanolides attracted our attention as synthetic targets.
O
O
+ MeOH
- MeOH
H
OH
H
OMe
N
N
O
S
S
O
O
O
O
(2R)- 1
(2R)- 2
*
Corresponding author. Tel.: +48 22 6320578; fax: +48 22 6326681;
e-mail: jurczak@icho.edu.pl
Scheme 1.
0957-4166/$ - see front matter ꢀ 2004 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tetasy.2004.10.025

3870
K. Kiegiel et al. / Tetrahedron: Asymmetry 15 (2004) 3869–3878
2. Results and discussion
afforded the mixture of diastereomers (20S)-3
and (20R)-3 (Scheme 2) in moderate to good yields but
the asymmetric induction was low (26–40% de). The
use of nonchelating Lewis acids, for example, BF3ÆEt2O
(entries 6–11) improved the diastereoselectivity substan-
tially (upto 60% de). A similar result concerning the dia-
stereoselectivity was obtained for the less active catalyst
MgBr2Æ2Et2O (entry 12). The best results in terms of
both chemical and diastereomeric excesses (58–84% de)
were obtained when the reaction was performed in the
presence of ZnCl2 or ZnBr2 (entries 13–19); the latter
Lewis acid was more selective. Application of hemiac-
etal 2 instead of free aldehyde 1 in the investigated reac-
tion often improved the yield, but had virtually no
influence on the diastereoselectivity of the process (com-
pare entries 13 and 14, or 15 and 16). When comparing
the allylating reagents in the reaction catalyzed by
ZnBr2, allyltrimethylsilane 4 gives a higher diastereose-
lectivity (upto 84% de), while the reaction with tin rea-
gents 5 and 6 (58–76% de, entries 17–19) is faster, less
demanding and more repeatable. The advantage of the
presented synthesis is its potential for easy preparation
of the pure diastereomer (20S)-3 by a simple, single
crystallization.
2.1. Preliminary investigations of the allylation of N-
glyoxyloyl-(2R)-bornane-10,2-sultam 1
In the first stage of our studies, we resolved to apply the
allylic Grignard reagent (Scheme 2, Table 1, entry 1).
The mixture of diastereomers (20S)-3 and (20R)-3 (70%
de) was obtained only in 35% yield (46% of bornane-
10,2-sultam was recovered). When the Grignard addi-
tion was modified using tetraisopropoxytitanium
(entries 2 and 3), the reaction yield increased substan-
tially, but the diastereoselectivity dropped.
Application of allyl bromide in the presence of zinc dust
(entries 4–6) improved the reaction yield, but the stereo-
selectivity remained on the level of 40% de.
The above-presented data show that the addition of the
Grignard reagent to the formyl groupis accompanied by
another process, namely the reaction of the allylic rea-
gent with the imido groupof 1. This results in the forma-
tion of bornane-10,2-sultam; the labile nature of the
imide bond in compound 1 precludes the use of such
organometallic reagents for allylation reactions.
2.3. Allylation of (1R)-8-phenylmenthyl glyoxylate with
allyltrimethylsilane or allyltributylstannane
2.2. Allylation of compounds 1 and 2 with allyltrimeth-
ylsilane or allyltributylstannane
The very promising results obtained using N-glyoxyloyl-
(2R)-bornane-10,2-sultam 1 or hemiacetal 2 should be,
however, confronted with an analogous reaction using
(1R)-8-phenylmenthyl glyoxylate 7. There are few exam-
ples of allylation of this substrate,5 with the resulting
diastereomeric excesses not exceeding 72%. The glyoxy-
late 7 was also used for the ene reaction with propene in
the presence of SnCl4, which afforded (20S)-8 in very
high yields and diastereoselectivities.3
N-Glyoxyloyl-(2R)-bornane-10,2-sultam 1 and its hemi-
acetal 2 were reacted with allyltrimethylsilane 4 or with
allyltributylstannane 5 (and in one case with tetraallyltin
6) in the presence of various Lewis acids. Under such
conditions, we did not observe splitting of the born-
ane-10,2-sultam. Results of our experiments are shown
in Table 2. Addition of 4 or 5 carried out in the presence
of a strong and chelating Lewis acid (entries 1–5)
Allylic
O
O
O
reagents:
H
AllylMgCl
N
N
N
AllylTi(OPri)3
+
AllylBr/Zn
OH
OH
O
S
S
S
AllylSiMe3
AllylSnBu3 5
(Allyl)4Sn
4
O
O
O
O
O
O
6
(2R)-1 or (2R)-2
(2'S)-3
(2'R)-3
Scheme 2.
Table 1. Results of the reaction of 1 with various allylating reagentsa
Entry
Allylating reagent
Additive
Time (h)
Yieldb (%)
Diastereomeric ratio
(20S)-3:(20R)-3c
De (%)
Auxiliary
recovered (%)
1
2
3
4
5
6
AllylMgCl
AllylMgCl
AllylTi(OPri)3
AllylBr
—
23
3
35
63
45
40
55
80
85:15
70:30
60:40
70:30
70:30
70:30
70
40
20
40
40
40
46
8
Ti(OPri)4
—
Zn
4
40
14
10
7
1
AllylBr
AllylBr
Zn, sonication
Zn, 10% TiCl4
1
1
a All reactions were carried out in THF at À78ꢁC.
b Isolated yield.
c Diastereoisomeric ratio was determined by 1H NMR.

K. Kiegiel et al. / Tetrahedron: Asymmetry 15 (2004) 3869–3878
3871
Table 2. Results of the reaction of 1 or 2 with allyltrimethylsilane 4, allyltributylstannane 5, or tetraallyltin 6, carried out in the presence of various
Lewis acidsa
Entry
Substrate
Allylating
reagent
Lewis acid
(1equiv)
Temp
(ꢁC)
Time
(h)
Yieldb
(%)
Diastereomeric ratio
(20S)-3:(20R)-3c
De
(%)
1
1
1
2
1
2
1
1
1
1
1
2
1
1
2
1
2
2
2
2
4
4
5
4
5
4
4
4
4
4
5
4
4
4
4
4
5
5
6
SnCl4
SnCl4
À40
À78
À20
À78
À20
20
4
18
2
80
45
95
55
86
70
65
65
62
45
47
70
70
85
75
95
91
65
97
63:27
69:31
70:30
65:35
65:35
75:25
74:26
80:20
79:21
72:28
80:20
80:20
89:11
86:14
91:9
26
38
40
30
30
50
48
60
58
44
60
60
78
72
82
84
64
76
58
2
3
SnCl4
TiCl4
TiCl4
4
65
2
5
6
BF3ÆEt2O
BF3ÆEt2O
BF3ÆEt2O
BF3ÆEt2O
BF3ÆEt2O
BF3ÆEt2O
MgBr2Æ2Et2O
ZnCl2
1
7
0
1
8
À20
À40
À78
20
1
9
4
10
11
12
13
14
15
16
17
18
19
18
1
25
0
21
2
ZnCl2
ZnBr2
0
3
0
2
ZnBr2
ZnBr2
0
20
6
92:8
2
82:18
88:12
79:21
ZnBr2
ZnBr2
0
3
0
2
a All reactions were carried out in the presence of 1equiv of Lewis acids in CH2Cl2.
b Isolated yield.
c Diastereomeric ratio was determined by 1H NMR, and in some cases the reaction mixture transformed to 4-allyl-2,2-dimethyl-1,3-dioxolane with de
confirmed using gas chromatography (GC) on a chiral capillary column.
We employed 8-phenylmenthyl glyoxylate 7 for the
allylation reaction using the silyl reagent 4 as well as
the tin reagent 5 in the presence of various Lewis acids
(Scheme 3, Table 3).
stereoselectivities (86–94%). The best results were ob-
tained using allyltributyltin and either BF3ÆEt2O or
SnCl4 as Lewis acids (99% yield, 92% de, entries 2 and
6). ZnBr2 also provides a very good diastereoselectivity
(94% de, entry 4) but the yields slightly lower. Com-
pared to the reaction using N-glyoxyloyl-(2R)-born-
ane-10,2-sultam 1, this approach gives much higher
Regardless the type of allylating reagent and catalyst
used, we obtained very good yields (77–99%) and dia-
Ph
Ph
Ph
AllylSiMe3 4 or
AllylSnBu3
O
O
O
5
H
+
O
O
O
O
OH
OH
(1R)-7
(2'S)-8
(2'R)-8
Scheme 3.
Table 3. Results of the reaction of 7 with 4 or 5, carried out in the presence of various Lewis acidsa
Entry
Allylating reagent
Lewis acid
Temp( ꢁC)
Yieldb (%)
Diastereomeric ratio
(20S)-3:(20R)-3c
De (%)
1
2
3
4
5
6
7
8
4
5
4
5
4
5
4
5
BF3ÆEt2O
BF3ÆEt2O
ZnBr2
ZnBr2
SnCl4
20
20
95
99
84
77
93
99
91
99
93:7
96:4
94:6
97:3
94:6
96:4
95:5
93:7
86
92
88
94
88
92
90
86
20
20
À20
À20
À20
À20
SnCl4
TiCl4
TiCl4
a All reactions were carried out in the presence of 1equiv of Lewis acids in CH2Cl2 for 1h.
b Isolated yield.
c The mixture of 8 was transformed to 4-allyl-2,2-dimethyl-1,3-dioxolane and the ratio determined using gas chromatography (GC) on a chiral
capillary column.

3872
K. Kiegiel et al. / Tetrahedron: Asymmetry 15 (2004) 3869–3878
diastereoselectivities, but, in contrary to that reaction, it
is difficult to purify the product to obtain a single
diastereomer.
2.4. The determination of the extent and direction of the
asymmetric induction
Following work-up, the crude reaction mixtures were
1
analyzed by H NMR to establish the diastereomeric
ratio of the adducts (20S)-3 and (20R)-3. The diastereo-
meric excess was confirmed by separation of the
mixture into single diastereomers via flash chromatogra-
phy or by analysis of the isopropylidene derivative of
pent-4-ene-1,2-diol (4-allyl-2,2-dimethyl-1,3-dioxolane)
using gas chromatography (GC) on a chiral capillary
column. The compound suitable for GC analysis was
obtained by reduction of 3 or 8 to pent-4-ene-1,2-diol,
followed by isopropylidene protection of the hydroxy
groups. The major diastereomer (20S)-3 was crystallized
to afford the single crystals suitable for X-ray analysis.
The structure of (20S)-3 showing the relative configura-
tion of the stereogenic centers is presented in Figure 1.
Figure 1. ORTEP drawing of compound (20S)-3.
approach of the allylic reagent to conformer B should oc-
cur from the topside of the bornane skeleton. There is an-
other possibility; the approach of the allylic reagent from
the bottom side to the less stable but most reactive (in
terms of LUMO level and atomic coefficients) SO2/CO
syn-periplanar, CO/CHO s-cis conformer B1. In this case
sterically controlled approach is reinforced by the cooper-
ative stereoelectronic effect.19 The same reasoning seems
to be correct in the case of reactions catalyzed by Lewis
acids (conformers B0 and B10).
The data presented in Tables 1 and 2 show that all addi-
tion reactions lead to the (20S)-3 diastereomer, preferen-
tially. Rationalization of our results concerning
allylation of 1 and 2 is based on the earlier work of
Oppolzer et al.17 and Curran et al.,18 and later by
us15a,19 formulated for the noncatalyzed reactions.
As suggested by X-ray analysis of N-acryloyl- and N-cro-
tonoyl-(2R)-bornane-10,2-sultam,17,18 for N-glyoxyloyl-
(2R)-bornane-10,2-sultam15b 1 the more stable CO/CHO
s-cis planar conformer B should be preferred over the con-
former s-trans A due to electrostatic and/or dipole–dipole
repulsion between the sultam oxygen and glyoxyloyl moi-
ety (Scheme 4). It is also noteworthy that in the presence
of a chelating Lewis acid, such as SnCl4, TiCl4, ZnBr2,
MgBr2Æ2Et2O, the CO/CHO s-cis conformation of the chi-
ral glyoxymides and glyoxylates is favored. Therefore, the
In the case of the allylation of (1R)-8-phenylmenthyl
glyoxylate we observed the same direction of asymmet-
ric induction to (20S)-8.5a
2.5. The synthesis of chiral 4-butanolides by iodolacton-
isation of 3
One of the useful methods for the synthesis of heterocy-
clic intermediates like 4-butanolides1c,20 or tetra-
sterically
sterically
favored
favored
re
O
si
O
H
O
si
N
O
N
O
N
O
H
O
O
S
S
S
O
H
O
O
O
re
electronically
favored
electronically +
sterically favored
A
B
B1
si
H
ZnBr2
O
O
N
O
N
O
ZnBr2
O
O
S
S
H
O
O
si
B'
B1'
Scheme 4. Stereochemical model of allylation.

K. Kiegiel et al. / Tetrahedron: Asymmetry 15 (2004) 3869–3878
3873
hydrofurans21 is the iodolactonization reaction of
homoallylic alcohols. We found in the literature that
the halolactonization reaction is mediated by a chiral
auxiliary.24 We studied the iodolactonization process
of enantiomerically pure homoallyl alcohol 3. This reac-
tion afforded a 75:25 mixture of 2,4-disubstituted-4-but-
anolides (2S,4R)-9 and (2S,4S)-9 (Scheme 5).
The chemical yield depends on the reaction conditions,
and can be improved upon substantially when the reac-
tion is carried out in the mixture of the tetrahydrofuran
and phosphate buffer (pH = 7.4). Chromatographic sep-
aration of the crude reaction mixture afforded both dia-
stereomeric adducts in analytically pure form. These
adducts were separately reduced to give the products
(2S,4S)-10 and (2S,4R)-10 without racemization.23 For
final justification of the configuration of our products,
we decided to transform the compound (2S,4S)-10 into
its crystalline derivative (2S,4S)-11 (Scheme 5), which
was then subjected to X-ray analysis. The results of this
study fully confirmed the configurations proposed by us
and are presented in Figure 2.
Figure 2. ORTEP drawing of compound (2S,4S)-11.
The trans-isomer (2S,4R)-9 was preferred in iodolacton-
ization reaction. Contrary to the imide (20S)-3, bromo-
and iodolactonization of 2-hydroxypent-4-enoic acid
proceeds in favor of the cis-isomer.20,1c For rationaliza-
tion of our result we proposed the transition states A
and B, which are presented in Scheme 6. The interaction
between the chiral auxiliary [(2R)-bornane-10,2-sultam]
and the Ca-stereogenic center forces the Ca-hydroxyl
substituent to adapt a pseudoaxial orientation in both
competing transition states A and B. We assume that
transition state A providing the trans-isomer (2S,4R)-9
is favored over B, because of the lack of 1,3-diaxial-like
interactions between the Ca-hydroxyl substituent and
ꢀiodine ionꢁ (olephinic moiety).
OH
OH
H
H
H
O
O
+
I
+
N
I
N
H
O
S
O
S
O
O
TS "A"
TS "B"
O
O
O
O
I
I
2.6. Synthesis of (2S,4S)-2-hydroxy-4-hydroxymethyl-4-
butanolide 13
HO
HO
First we tried to construct the diacetyl derivatives of
(2S,4S)-2-hydroxy-4-hydroxymethyl-4-butanolide
(2S,4R)-9
(2S,4S)-9
by
acetoxylactonization of (20S)-3 (Scheme 7). This attempt
Scheme 6. Stereochemical model of iodolactonization.
O
O
O
O
O
a
I
I
+
N
HO
HO
OH
S
O
O
(2S,4R)-9
(2S,4S)-9
75:25
(2'S)-3
b
b
O
O
O
Me
Me
Me
O
O
O
c
p-NO2C6H4CO2
HO
HO
(2S,4S)-11
(2S,4S)-10
(2S,4R)-10
Scheme 5. Reagents and conditions: (a) 3equiv I2, THF/H2O 1.5:1, pH = 7.4, 24h; (b) Bu3SnH, AIBN, toluene, 100ꢁC; (c) p-NO2C6H4COCl,
pyridine/CH2Cl2.

3874
K. Kiegiel et al. / Tetrahedron: Asymmetry 15 (2004) 3869–3878
O
O
O
O
O
N
a
OAc
OAc
+
OH
S
AcO
AcO
O
O
(2'S)-3
(2S,4R)-12
(2S,4S)-12
1:1
b
H2O
O
O
O
O
O
OH
-H+
O
O
+
c
....
O
I
Ag
I
OH
HO
HO
HO
HO
(2S,4R)-9
(2S,4S)-13
Scheme 7. Reagents and conditions: (a) (NH4)2S2O8, CF3SO3H, AcOH, 70ꢁC; (b) 3equiv I2, THF/H2O 1.5:1, pH = 7.4, 24h; (c) AgNO2, EtOH/H2O
1:1, reflux, 3h.
was unsuccessful, because this reaction afforded a 1:1
mixture of cis- and trans-isomers, (2S,4R)-12 and
(2S,4S)-12, respectively, as resulted from the H NMR
study.12b,c Therefore, we obtained the desired com-
pound (2S,4S)-1310,12–14 by treating the major product
of iodolactonization (2S,4R)-9 with the silver nitrite in
aqueous ethanol (Scheme 7).24
Ce(SO4)2 in 15% H2SO4. Flash chromatography was
performed using silica gel 60 (40–63lm) (Merck). Melt-
ing points (uncorrected) were determined using a Ko¨fler-
type hot-stage apparatus (Boetius). Optical rotations
were taken using Perkin–Elmer-241 polarimeter. IR
spectra in KBr pellets were recorded on a Perkin–Elmer
1640 FTIR spectrometer. 1H and 13C NMR spectra
were recorded using Varian Gemini-200 or Varian-
Unity Plus-500 spectrometers. Mass spectra were
recorded using AMD-604 Intectra instrument in the
electron impact (EI) mode. Ratio of (R)/(S)-4-allyl-2,
2-dimethyl-1,3-dioxolane was determined by gas chro-
matography performed using a Shimadzu GC unit
equipped with a capillary chiral column b-dex 120 (per-
methyl-b-cyclodextrin, 30m · 0.25mm I.D. Supelco,
Bellefonte, USA). Chromatography conditions: carrier
gas—nitrogen, 100kPa; injection temp200 ꢁC; detector
temp250 ꢁC; oven temp90 ꢁC, (R)-isomer, 7.1min, (S)-
isomer, 7.3min.
1
One can see that the latter reaction proceeds with inver-
sion of configuration at the C-4 stereogenic center. The
stereochemical outcome can be explained as outlined in
Scheme 7. We speculate that the inversion of the C-4
stereocenter is established through the epoxide interme-
diate giving rise to (2S,4S)-13 by 5-exo ring closure, as is
generally observed. The product of the 6-endo ring clo-
sure was not observed in the post-reaction mixture.
3. Conclusions
Herein, we have reported the results of the stereose-
lective two-stepconversion of
4.2. Synthesis of the adducts (20S)-3 and (20R)-3
N-glyoxyloyl-(2R)-
bornane-10,2-sultam into enantiomerically pure
1
4.2.1. Addition of allylmagnesium chloride to N-glyoxyl-
oyl-(2R)-bornane-10,2-sultam 1. To a stirred solution
of N-glyoxyloyl-(2R)-bornane-10,2-sultam 1 (272mg,
1mmol) in dry THF (ca. 10mL) under argon, the solu-
tion of allylmagnesium chloride in THF (2M, 0.75mL,
1.5mmol) was added dropwise at À78ꢁC, and stirring
continued at this temperature for 23h. The reaction
was quenched with satd NH4Cl and the aqueous layer
extracted with Et2O (3 · 30mL). The separated organic
layers were combined, dried over MgSO4, and concen-
trated in vacuo. Flash chromatography (hexane–ethyl
acetate, 9:1 ! 7:3) of the residue afforded the homoallyl
alcohols 3 (107mg, 35%).
c-butyrolactones. The auxiliary mediates diastereoselec-
tive C–C bond formation in the first step, and the dia-
stereoselective heterocyclization in the second step.
The results presented above demonstrate that it is possi-
ble to control the diastereoselectivity of the allylation of
glyoxylic acid derivatives, and then to control the dia-
stereoselectivity of iodolactonization. Additionally, we
have presented a highly efficient and diastereoselective
method of allylation of 8-phenylmenthyl glyoxylate.
4. Experimental
4.1. General
4.2.2. Addition of allyltitanium reagents to N-glyoxyloyl-
(2R)-bornane-10,2-sultam 1. To a solution of the allyl-
titanium reagent (1.5mmol), prepared according to the
procedure given below, the solution of compound 1
(272mg, 1mmol) in dry THF (10mL) was added drop-
wise at À78ꢁC. The reaction was stirred at the same
Solvents were freshly distilled from CaH2 or Na/benzo-
phenone. Analytical TLC was performed using plates
precoated with silica gel 60 F254 (Merck); detection by
spraying with a solution of 2% molybdic acid and 1%

K. Kiegiel et al. / Tetrahedron: Asymmetry 15 (2004) 3869–3878
3875
temperature for the period of time indicated in Table 1.
The reaction was quenched with satd NH4Cl and ex-
tracted with Et2O (3 · 30mL). The organic layers were
combined, dried over MgSO4, and concentrated in
vacuo. Flash chromatography (hexane–ethyl acetate)
of the residue afforded homoallyl alcohols 3.
over MgSO4, and concentrated in vacuo. Flash chroma-
tography (hexane–ethyl acetate) afforded homoallyl
alcohols 3.
4.2.5. Addition of allylstannanes to hemiacetal 2. To a
stirred solution of 2 (303mg, 1mmol) in dry CH2Cl2
(5–10mL) the Lewis acid (1.0–1.1mmol) was added.
After additional stirring (10min), allyltributyltin 5
(402lL, 1.3mmol) or tetraallyltin 6 (84lL, 0.35mmol)
was added dropwise at a temperature indicated in Table
2. Stirring was continued for the period of time indi-
cated in Table 2. The reaction was quenched with 20%
NH4F and extracted with Et2O (3 · 30mL). The com-
bined organic layers were dried over MgSO4, and con-
centrated in vacuo. Flash chromatography (hexane–
ethyl acetate, 9:1 ! 7:3) afforded homoallyl alcohols 3.
4.2.2.1. Preparation of the allyltitanium reagents
4.2.2.1.1. The complex of allylmagnesium chloride with
Ti(OPri)4. A solution of allylmagnesium chloride in
THF (2M, 0.75mL, 1.5mmol) was added to a cooled
(À78ꢁC) solution of titanium(IV) isopropoxide
(0.44mL, 1.5mmol) in dry THF (1.5mL) under an
argon atmosphere. The mixture was stirred at the same
temperature for 10min.
4.2.2.1.2. Allyltri(isopropoxy)titanium. The solution
of allylmagnesium chloride in THF (2M, 0.75mL,
1.5mmol) was added to a solution of tri(isoprop-
oxy)titanium chloride in dry CH2Cl2 (1M, 1.5mL,
1.5mmol), at À78ꢁC, under an argon atmosphere. The
mixture was stirred at À78ꢁC for 10min.
4.2.6. Analytical and spectral data for the compound
20
(20S)-3. Mp138–139 ꢁC; ½aŠ = À105.0 (c 2.2, CHCl3);
D
1H NMR (200MHz, CDCl3), d: 5.90–5.70 (m, 1H,
CH@CH2), 5.20–5.07 (m, 2H, C@CH2), 4.89–4.78 (m,
1H, CHOH), 3.94 (dd, J = 7.4, 5.0Hz, 1H, CHN), 3.52
(1/2 ABq, J = 13.8Hz, 1H, CHSO2), 3.48 (1/2 ABq,
J = 13.8Hz, 1H, CHSO2), 3.08 (d, J = 7.7Hz, 1H,
OH), 2.75–2.41 (m, 2H,CH2) 2.15–1.29 (m, 7H,
3 · CH2 and 1 · CH), 1.14 (s, 3H, CH3), 0.98 (s, 3H,
CH3); 13C NMR (50MHz, CDCl3), d: 174.2, 132.0,
118.9, 70.3, 64.9, 52.9, 48.9, 47.8, 44.5, 39.8, 38.2, 32.7,
26.4, 20.7, 19.8; IR (KBr): 3552, 3001, 2959, 1696,
1641, 1331, 1058, 774; EIMS m/z (%): 313 (M+, 1.3),
295 (1.8), 272 (33), 199 (9), 135 (100), 93 (47), 71 (13),
55 (6); Anal. Calcd for C15H23NO4S: C, 57.5; H, 7.4;
N, 4.0; S, 10.2; found: C, 57.3; H, 7.5; N, 4.4; S, 10.2.
4.2.3. Addition of allyl bromide to N-glyoxyloyl-(2R)-
bornane-10,2-sultam 1 in the presence of zinc pow-
der. To a mixture of allyl bromide and zinc (prepared
according to the procedure given below), a solution of
compound 1 (1mmol) in dry THF (10mL) was added
dropwise at À78ꢁC. The reaction was stirred at the same
temperature for the period of time indicated in Table 1.
The reaction was quenched with satd NH4Cl and
extracted with Et2O (3 · 30mL). The organic layers
were combined, dried MgSO4, and concentrated in
vacuo. Flash chromatography (hexane–ethyl acetate)
of the residue afforded homoallyl alcohols 3.
4.2.7. Analytical and spectral data for the compound
20
D
4.2.3.1. Preparation of the mixture of allyl bromide
and zinc
(20R)-3. Mp69–70 ꢁC; ½aŠ = À97.7 (c 1.08, CHCl3);
1H NMR (200MHz, CDCl3); d: 5.97–5.76 (m, 1H,
CH@CH2), 5.25–5.11 (m, 2H, C@CH2), 4.72–4.61 (m,
1H, CHOH), 3.91 (dd, J = 7.7, 5.1Hz, 1H, CHN), 3.53
(1/2 ABq, J = 14.0Hz, 1H, CH2SO2), 3.48 (1/2 ABq,
J = 14.0Hz, 1H, CH2SO2), 3.14 (d, J = 7.4Hz, 1H,
OH), 2.73–2.40 (m, 2H, CH2), 2.29–1.20 (m, 7H,
3 · CH2 and 1 · CH), 1.15 (s, 3H, CH3), 0.97 (s, 3H,
CH3); 13C NMR (50MHz, CDCl3): d: 171.8, 133.1,
118.5, 70.3, 65.3, 52.9, 49.3, 47.9, 44.5, 38.1, 37.0, 32.8,
26.5, 20.7, 19.9; IR (KBr): 3561, 3078, 2964, 1699,
1640, 1134, 1056, 764; EIMS m/z (%): 313 (M+, 3), 295
(6), 272 (31), 199 (8), 135 (100), 93 (48), 71 (15), 55
(8); HR-EIMS calcd for C15H23NO4S (M+): 313.13478,
found: 313.1352; calcd for C12H18NO4S (M+ÀC3H5):
272.0956, found: 272. 0951.
4.2.3.1.1. Method A. Allyl bromide (0.13mL, 1.5
mmol) was added to the suspension of zinc powder
(98mg, 1.5mmol) in dry THF (2.5mL). The mixture
was stirred at room temperature for 30min.
4.2.3.1.2. Method B. A suspension of zinc powder
(98mg, 1.5mmol) in dry THF (2.5mL) was sonicated
(40kHz) for 15min. Then allyl bromide (0.13mL,
1.5mmol) was added and the mixture was stirred at
room temperature for 30min.
4.2.3.1.3. Method C. The solution of allyl bromide
(0.13mL, 1.5mmol) in dry THF (1.5mL) was added
dropwise to a suspension of zinc powder (98mg,
1.5mmol) and titanium(IV) chloride (17lL, 0.15mmol)
in dry THF (1mL), and stirring continued at room tem-
perature for 15min.
4.3. Addition of allyltrimethylsilane or allyltributylstann-
ane to (1R)-8-phenylmenthyl glyoxylate 6
4.2.4. Addition of allyltrimethylsilane to N-glyoxyloyl-
(2R)-bornane-10,2-sultam 1 or its hemiacetal 2. To a
stirred solution of 1 or 2 (1mmol) in dry CH2Cl2 (10–
15mL) at a temperature indicated in Table 2, the Lewis
acid (1mmol) was added under argon. After additional
stirring (5min), allyltrimethylsilane (320lL, 2mmol)
was added dropwise. Stirring was continued for the per-
iod of time indicated in Table 2. The reaction was
quenched with satd NH4Cl and extracted with Et2O
(3 · 30mL). The organic layers were combined, dried
To a stirred solution of 6 (289mg, 1mmol) in dry
CH2Cl2 (10mL) the Lewis acid (1.0–1.1mmol) was
added and after 10min at a temperature indicated in Ta-
ble 3 allyltrimethylsilane (320lL, 2mmol) or allyltribu-
tyltin (402lL, 1.3mmol) was added. Stirring was
continued for the period of time indicated in Table 3.
The reaction was quenched with 20% NH4Cl and ex-
tracted with Et2O (3 · 30mL). The combined organic

3876
K. Kiegiel et al. / Tetrahedron: Asymmetry 15 (2004) 3869–3878
layers were pooled, dried over MgSO4, and concentrated
in vacuo. Flash chromatography (hexane–ethyl acetate)
afforded homoallyl alcohols 8. The NMR data of com-
ture was stirred at the same temperature for 1h and then
concentrated in vacuo. Flash chromatography of the
residue (hexane–ethyl acetate 3:1) afforded the corre-
sponding butanolide (60mg, 0.52mmol, 89%) as an oil.
pounds 8 are in agreement with those described in the
20
D
literature.5a Specific rotations for (20S)-8: ½aŠ = À7.9
(c 1.82, CHCl3); lit.5a [a]D = À6.2 (c 1.75, CHCl3).
4.5.1. Analytical and spectral data for the compound
20
D
(2S,4S)-10. Colorless oil; ½aŠ = À64.5 (c, 1.9, MeOH);
20
D
1
4.4. Synthesis of (2S,4R)- and (2S,4S)-2-hydroxy-4-
iodomethyl-4-butanolide 9
lit.21a ½aŠ = À59.8 (c 1, MeOH); H NMR (500MHz,
CDCl3), d: 4.86–4.78 (m, 1H, CHCH3), 4.58 (t,
J = 7.5Hz, 1H,CHOH), 3.2 (br s, 1H, OH), 2.43–2.34
(m, 1H, CHCHOH), 2.26–2.19 (m, 1H, CHCHOH),
1.41 (d, J = 6.0Hz, 3H, CH3); 13C NMR (125MHz,
CDCl3), d: 177.9, 75.2, 67.5, 37.1, 21.3; IR (film):
3383, 2983, 1769, 1128, 952; EIMS m/z (%) 117
([M+H]+) (2), 101 (3), 89 (8), 72 (15), 57 (100), 43
(41); HR-EIMS calcd for C4H5O3 (MÀCH3)+:
101.0239, found: 101.0242.
To a solution of compound (20S)-3a (1.0g, 3.19mmol) in
a mixture of THF/phosphoric buffer (pH = 7.4) (20mL,
12:8) was added iodine (2.45g, 9.6mmol) at ambient
temperature. The reaction mixture was stirred for 24h.
To the resultant solution was added satd Na2S2O3
(5mL) and stirring continued for 15min. Then the layers
were separated and the aqueous layer extracted with
Et2O (3 · 50mL). The organic layers were combined,
washed twice with satd NaHCO3, once with satd brine,
dried over MgSO4, and concentrated in vacuo. Flash
chromatography (hexane–ethyl acetate 8:2 ! 7:3) of
the residue afforded the compounds (2S,4R)-9 (349mg,
1.44mmol, 45%) and (2S,4S)-9 (116mg, 0.48mmol,
15%). (2R)-Bornane-10,2-sultam (615mg, 2.86mmol,
89%) was also isolated after the chromatography.
4.6. Synthesis of (2S,4R)-2-hydroxy-4-methyl-4-butano-
lide 10
The title product was obtained in the same manner as
described for the preparation of (2S,4S)-2-hydroxy-4-
methyl-4-butanolide 10. (2S,4S)-9 (50mg; 0.21mmol),
yield 17mg (70%) of (2S,4R)-10 as an oil.
4.4.1. Analytical and spectra data for the compound
4.6.1. Analytical and spectral data for the compound
(2S,4R)-10. Colorless oil; 1H NMR (500MHz,
CDCl3), d: 4.56 (dd, J = 11.0, 8.3Hz, 1H, CHOH),
4.55–4.48 (m, 1H, CHCH3), 2.73 (ddd, J = 12.5, 8.3,
5.0Hz, 1H, CHCHOH), 2.6 (br s, 1H, OH), 1.88 (ddd,
J = 12.5, 11.0, 10.5Hz, 1H, CHCHOH), 1.48 (d,
J = 6.0Hz, 3H, CH3); 13C NMR (125MHz, CDCl3), d:
177.6, 73.7, 69.0, 38.7, 20.9; IR (film): 3386, 2982,
1769, 1389, 1205, 1132, 999, 945.
20
(2S,4R)-9. Colorless oil; ½aŠ = À9.3 (c, 1.22, CHCl3);
D
1H NMR (500MHz, CDCl3), d: 4.77–4.71 (m, 1H,
CHCH2I), 4.67 (t, J = 7.6Hz, 1H, CHOH), 3.37 (1/2
ABq, J = 10.0, 4.4Hz, 1H, CHI), 3.36 (1/2 ABq,
J = 10.0, 6.8Hz, 1H, CHI), 2.95 (s, 1H, OH), 2.44 (dd,
J = 7.6, 6.4Hz, 2H, CH2CHOH), 13C NMR (125MHz,
CDCl3), d: 176.8, 76.7, 67.4, 35.7, 7.3; IR (film): 3386,
1778, 1174, 1116, 611; EIMS m/z (%): 242 (M+) (7.6),
169 (2.6), 141 (5.0), 127 (7.0), 77 (7.0), 71 (100), 43
(72); HR-EIMS calcd for C5H7IO3 (M+): 241.9440,
found: 241.9419.
4.7. Synthesis of (2S,4S)-2-nitrobenzoyloxy-4-methyl-4-
butanolide 11
4.4.2. Analytical and spectral data for compound (2S,
Compound (2S,4S)-10 (30mg, 0.26mmol) was dissolved
in dry CH2Cl2 (2mL) and then p-nitrobenzoyl chloride
(120mg, 0.65mmol) added. The reaction mixture was
cooled under argon to 0ꢁC and pyridine (0.06mL,
0.71mmol) added dropwise. After stirring at 0ꢁC for
10min, the reaction mixture was allowed to reach room
temperature, and stirring continued for an additional
1h. Water (5mL) was then added and the reaction mix-
ture diluted with Et2O (30mL). The organic layer was
washed with satd NaHCO3 (3 · 20mL), dried over
MgSO4, and concentrated in vacuo. Flash chromatogra-
phy of the residue (hexane–ethyl acetate 85:15) of the
residue afforded product 11 as white crystals (53mg,
0.20mmol, 77%). The product was recrystallized from
the mixture of hexane and EtOAc.
20
4S)-9. Colorless oil; ½aŠ ¼ À39:24 (c, 1.26, CHCl3);
D
1H NMR (500MHz, CDCl3), d: 4.60 (dd, J = 11.0,
8.5Hz, 1H, CHOH), 4.51–4.41 (m, 1H, CHCH2I), 3.46
(1/2 ABq, J = 10.0, 5.0Hz, 1H, CHI), 3.32 (1/2 ABq,
J = 10.0, 7.5Hz, 1H, CHI), 3.3 (br s, 1H, OH), 2.94–
2.86 (m, 1H, CHCHOH), 2.05–1.90 (m, 1H,
CHCHOH); 13C NMR (125MHz, CDCl3), d: 176.5,
75.5, 68.8, 37.3, 5.4; IR (film in CCl4): 3409, 1777,
1171, 1118, 997, 798; EIMS m/z (%): 242 (M+) (46),
167 (9), 141 (6), 127 (6), 71 (100), 43 (75); Anal. Calcd
for C5H7IO3: C, 24.81; H, 2.92; found: C, 24.85; H, 3.10.
4.5. Synthesis of (2S,4S)-2-hydroxy-4-methyl-4-butano-
lide 10
To the solution of (2S,4R)-2-hydroxy-4-iodomethyl-4-
butanolide (2S,4R)-9 (142mg, 0.58mmol) in dry toluene
(3mL) was added a crystal of AIBN, followed by slow
addition of tri(n-butyl)tin hydride (0.19mL, 0.70mmol)
under argon. The reaction mixture was heated at
100ꢁC for 18h. Then the solvent was evaporated, the
residue was cooled (0ꢁC), and a mixture of trifluoroace-
tic acid and water (2mL, 9:1) added. The reaction mix-
4.7.1. Analytical and spectral data for the compound
20
D
(2S,4S)-11. Mp142–143 ꢁC; ½aŠ = À29.8 (c, 1.07,
1
CHCl3); H NMR (500MHz, CDCl3), d: 8.35–8.22 (m,
4H, PhH), 5.72 (dd, J = 8.5, 7.5Hz, 1H, CHOCOC6H4-
NO2), 4.98–4.87 (m, 1H, CHCH3), 2.61–2.45 (m, 2H,
CH2CHOH), 1.51 (d, J = 6.5Hz, 3H, CH3), 13C NMR
(125MHz, CDCl3), d: 171.9, 150.9, 134.1, 131.2, 132.7,
74.9, 69.4, 35.4, 21.6; IR (KBr): 3114, 1787, 1731,

K. Kiegiel et al. / Tetrahedron: Asymmetry 15 (2004) 3869–3878
3877
1609, 1528, 1353, 1274, 1097, 719; LSIMS (M)+: 553
(2M+Na)+, 266 (M+H)+; HR-LSIMS calcd for
C12H12O6 (M+H)+: 266.06646, found: 266.06703.
1187, 1169, 1105, 1047, 933, 843, 602; EIMS m/z (%):
217 ([M+H]+, 0.5), 143 (7.6), 115 (8.8), 103 (7.6), 83
(4.7), 70 (7.0), 61 (4.7), 43 (100); LSIMS (M)+:455
(2M+Na)+, 433 (2M+H)+, 239 (M+Na)+, 217
(M+H)+; HR-LSIMS calcd for C9H13O6 (M+H)+:
217.0712, found: 217.0708.
4.8. Synthesis of (2S,4R)- and (2S,4S)-2-acetoxy-4-acet-
oxymethyl-4-butanolide 12
A mixture of adduct (20S)-3 (160mg, 0.51mmol), ammo-
nium persulfate (351mg, 1.54mmol), and trifluorometh-
anesulfonic acid (0.14mL, 1.54mmol) in acetic acid
(1.5mL) was stirred at 70ꢁC for 3h. The cooled mixture
was poured into water and extracted with ethyl acetate
(3 · 30mL). The organic layers were combined, washed
with satd NaHCO3, dried over MgSO4, and concen-
trated in vacuo. The resulting residue was purified by
column chromatography on silica gel. Elution with hex-
ane–ethyl acetate (8:2 ! 7:3) gave a nonseparable mix-
ture (1:1) of the diastereomers of 12 (77mg,
0.35mmol, 70%) as a colorless oil. (2R)-Bornane-10,2-
sultam (44mg, 0.20mmol, 40%) and N-acetyl-(2R)-
bornane-10,2-sultam (51mg, 0.20mmol, 40%) were also
isolated after the chromatography.
4.9. Synthesis of (2S,4S)-2-hydroxy-4-hydroxymethyl-4-
butanolide 13
A suspension of AgNO2 (0.5g, 3.2mmol) and com-
pound (2S,4R)-9 (121mg, 0.5mmol) in a mixture of
EtOH–H2O 10:1 (6mL) was refluxed for 3h. After filter-
ing off the solid on Celite and washing with ethanol, the
solution was concentrated in vacuo. Purification by col-
umn chromatography (ethyl acetate as eluent) afforded
the compound 13 (30mg, 0.23mmol, 46%).
4.9.1. Analytical and spectral data for compound (2S,
20
4S)-13. Colorless oil; ½aŠ = +18.7 (c, 0.76, MeOH);
D
1
lit.10 [a] = +23.2 (c 3.61, MeOH); H NMR (500MHz,
CD3OD), d: 4.56 (dd, J = 10.7, 8.5Hz, 1H, CHOH),
4.50–4.42 (m, 1H, CHCH2OH), 3.80 (dd, J = 12.5,
5.3Hz, CHCHOH), 3.59 (dd, J = 12.5, 5.3Hz, 1H,
CHCHOH), 2.53 (ddd, J = 11.7, 8.5, 5.8Hz, 1H,
CHCHOH), 1.98 (ddd, J = 11.7, 10.7, 10.7Hz,
CHCHOH), 13C NMR (125MHz, CDCl3), d: 179.1,
78.6, 69.3, 63.8, 33.6, EIMS m/z (%): 133 ([M+H]+),
102 (26), 87 (11), 73 (100), 70 (20), 43 (13),LSIMS
(M)+: 265 (2M+H)+, 133 (M+H)+.
4.8.1. Analytical and spectra data for compounds cis/
trans-12.12b,c 1H NMR (500MHz, CDCl3), d: 5.55–
5.45 (m, 2 · 1H, CHOAc, cis + trans), 4.92–4.86 (m,
1H, OCHCH2OAc, trans), 4.72–4.65 (m, 1H, OCH-
CH2OAc, cis), 4.42–4.30 (m, 2 · 1H, CH2OAc, cis +
trans), 4.23–4.14 (m, 2 · 1H, CH2OAc, cis + trans),
2.82–2.74 (m, 1H, CH2CHOAc, cis), 2.63–2.53 (m, 1H,
CH2CHOAc, trans), 2.47–2.36 (m, 1H, CH2CHOAc,
trans), 2.18 (s, 3H, CH3, trans), 2.17 (s, 3H, CH3, cis),
2.13 (s, 3H, CH3, trans), 2.12 (s, 3H, CH3, cis), 2.12–
2.02 (m, 1H, CH2CHOAc, cis); 13C NMR (125MHz,
CDCl3), d: 172.3, 171.6, 170.5, 170.3, 169.8, 169.7,
74.8, 74.0, 68.0, 67.5, 65.1, 64.3, 30.9, 30.7, 20.8, 20.7,
20.6; IR (CCl4): 2961, 1808, 1754, 1453, 1374, 1227,
4.10. The X-ray structure investigations for compounds
(20S)-3 and (2S,4S)-11
The crystal data for both structures were measured on
MACH3 j-diffractometer using CuKa radiation and
x–2h scan mode. Structures were solved using direct
Table 4. Crystal data and structure refinement for compounds (20S)-3 and (2S,4S)-11
Identification code
Empirical formula
Formula weight
Temperature (K)
˚
Wavelength (A)
Crystal system, space group
(20S)-3
C15H23NO4S
(2S,4S)-11
C12H11NO6
313.40
293(2)
265.22
293(2)
1.54178
1.54178
Orthorhombic, P212121
a = 8.115(2)
Orthorhombic, P212121
a = 7.7672(5)
b = 7.7585(14)
c = 23.147(6)
˚
Unit cell dimensions (A)
b = 12.7820(10)
c = 14.8690(10)
1542.3(4)
3
˚
Volume (A )
1394.9(4)
4, 1.263
Z, calculated density (mgmÀ3
)
4, 1.350
2.003
Absorption coefficient (mmÀ1
F(000)
Crystal size (mm)
)
0.884
552
672
0.7 · 0.35 · 0.15
4.56–75.04
0.35 · 0.35 · 0.18
3.82–67.41
Theta range for data collection
Index ranges
À10 6 h 6 10, 0 6 k 6 15, 0 6 l 6 18
1506/1506 [R(int) = 0.0000]
Full-matrix least-squares on F2
1506/0/279
À7 6 h 6 0, À9 6 k 6 0, 0 6 l 6 26
1199/1199 [R(int) = 0.0000]
Full-matrix least-squares on F2
1199/0/173
Reflections collected/unique
Refinement method
Data/restraints/parameters
Goodness-of-fit on F2
Final R indices [I > 2r(I)]
R indices (all data)
1.055
1.095
R1 = 0.0430, wR2 = 0.1174
R1 = 0.0441, wR2 = 0.1190
0.03(4)
R1 = 0.0343, wR2 = 0.0955
R1 = 0.0390, wR2 = 0.1009
À0.3(4)
Absolute structure parameter
Extinction coefficient
Largest diff. peak and hole (eA
0.0006(4)
0.288 and À0.250
0.081(4)
À3
˚
)
0.154 and À0.152

3878
K. Kiegiel et al. / Tetrahedron: Asymmetry 15 (2004) 3869–3878
11. Moriarty, R. M.; Kim, J.; Brumer, H., III. Tetrahedron
Lett. 1995, 36, 51–54.
methods (SHELXS program) and refined using SHELX97
program. Table 4 shows details of data collection and
structure refinement. Crystallographic data (excluding
structure factors) have been deposited with Cambridge
Crystallographic Data Centre as supplementary publica-
tion number CCDC 239175 for compounds (20S)-3 and
number CCDC 239176 for compounds (2S,4S)-11. Cop-
ies of the data can be obtained, free of charge, on appli-
cation to CCDC, 12 Union Road, Cambridge CB2 1EZ,
UK (fax: +44-1223-336033 or deposit@ccdc.cam.ac.uk).
ˇ
ˇ
ˇ´
´
´
12. (a) Kucar, S.; Zamocky, J.; Bauer, S. Collect. Czech.
Chem. Commun. 1975, 40, 457–461; (b) Bock, K.; Lundt,
I.; Pedersen, C. Acta Chem. Scand. B 1981, 35, 155–162;
(c) Okabe, M.; Sun, R.-C.; Zenchoff, G. B. J. Org. Chem.
1991, 56, 4392–4397; (d) Matsumoto, K.; Ebata, T.;
Koseki, K.; Kawakami, K.; Okano, K.; Matsushita, H.
Heterocycles 1992, 34, 363–367; (e) Choquet-Farnier, C.;
`
Stasik, I.; Beaupere, D. Carbohydr. Res. 1997, 303, 185–
191.
13. (a) Xie, Z.-F.; Sakai, K. Chem. Pharm. Bull. 1989, 37,
1650–1652; (b) Xie, Z.-F.; Suemune, H.; Sakai, K.
Tetrahedron: Asymmetry 1993, 4, 973–980.
References
14. (a) Ticozzi, C.; Zanarotti, A. Tetrahedron Lett. 1994, 35,
7421–7424; (b) Enders, D.; Sun, H.; Leusink, F. R.
Tetrahedron 1999, 55, 6129–6138.
1. For application of 2-hydroxypent-4-enoic acid and its
esters, see: (a) Dauben, W. G.; Hendricks, R. T.; Pandy,
B.; Wu, S. C. Tetrahedron Lett. 1995, 36, 2385–2388; (b)
Rutjes, F. P. J.; Kooistra, T. M.; Hiemstra, H.; Schoe-
maker, H. S. Synlett 1998, 192–194; (c) Macritchie, J. A.;
Peakman, T. M.; Silcock, A.; Willis, C. L. Tetrahedron
Lett. 1998, 39, 7415–7418.
15. (a) Bauer, T.; Chapuis, C.; Kozak, J.; Jurczak, J. Helv.
_
Chim. Acta 1989, 72, 482–486; (b) Bauer, T.; Jezewski, A.;
Chapuis, C.; Jurczak, J. Tetrahedron: Asymmetry 1996, 7,
1385–1390.
16. (a) Whitesell, J. K.; Liu, C.-L.; Buchanan, C. M.; Chen,
H.-H.; Minton, M. A. J. Org. Chem. 1986, 51, 551–553;
(b) Ort, O. Org. Synth. 1987, 65, 203–214.
2. For application of pent-4-ene-1,2-diol and its 1-monopro-
tected derivative, see: (a) Zemribo, R.; Mead, K. T.
´
Tetrahedron Lett. 1998, 39, 3895–3898; (b) Dıaz, Y.;
Bravo, F.; Castillon, S. J. Org. Chem. 1999, 64, 6508–6511;
(c) Ghosh, A. K.; Lei, H. J. Org. Chem. 2000, 65, 4779–
4781.
17. (a) Oppolzer, W.; Chapuis, C.; Bernardinelli, G. Helv.
Chim. Acta 1984, 67, 1397–1401; (b) Oppolzer, W.; Poli,
G.; Starkemann, C.; Bernardinelli, G. Tetrahedron Lett.
1988, 29, 3559–3562.
´
18. Curran, D. P.; Kim, B. H.; Daugherty, J.; Heffner, T. A.
Tetrahedron Lett. 1988, 29, 3555–3558.
19. Bauer, T.; Chapuis, C.; Jezewski, A.; Kozak, J.; Jurczak, J.
Tetrahedron: Asymmetry 1996, 7, 1391–1404.
20. For the previous works on the halolactonization of
racemic 2-hydroxy-4-pentenoic acid, see: (a) Ohfune, Y.;
Hori, K.; Sakaitani, M. Tetrahedron Lett. 1986, 27, 6079–
6082; (b) Kitagawa, O.; Sato, T.; Taguchi, T. Chem. Lett.
1991, 177–180.
3. Whitesell, J. K.; Bhattacharya, A.; Buchanan, C. M.;
Chen, H. H.; Deyo, D.; James, D.; Liu, C.-L.; Minton, M.
A. Tetrahedron 1986, 42, 2993–3001.
4. (a) Jung, J. E.; Ho, H.; Kim, H.-D. Tetrahedron Lett.
2000, 41, 1793–1796; (b) Yu, H.; Ballard, C. E.; Wang, B.
Tetrahedron Lett. 2001, 42, 1835–1838.
5. (a) Macritchie, J. A.; Silcock, A.; Willis, C. L. Tetrahe-
dron: Asymmetry 1997, 8, 3895–3902; (b) Loh, T.-P.; Xu,
J. Tetrahedron Lett. 1999, 40, 2431–2434.
21. (a) Bennett, F.; Bedford, S. B.; Bell, K. E.; Fenton, G.;
Knight, D. W.; Shaw, D. Tetrahedron Lett. 1992, 33,
6507–6510; (b) Bedford, S. B.; Bell, K. E.; Bennett, F.;
Hayes, C. J.; Knight, D. W.; Shaw, D. J. Chem. Soc.,
Perkin Trans. 1 1999, 2143–2153.
24. (a) Fuji, K.; Node, M.; Naniwa, Y.; Kawabata, T.
Tetrahedron Lett. 1990, 31, 3175–3178; (b) Yokomatsu,
T.; Iwasawa, H.; Shibuya, S. J. Chem. Soc., Chem.
Commun. 1992, 728–729.
23. For previous works on the synthesis and stereochemistry
of compounds 10, see: (a) Arens, H.; Paetow, M.; Hoppe,
D. Tetrahedron Lett. 1992, 33, 5327–5330; (b) Blandin, V.;
Carpentier, J.-F.; Mortreux, A. Tetrahedron: Asymmetry
1998, 9, 2765–2768; (c) Blandin, V.; Carpentier, J.-F.;
Mortreux, A. Eur. J. Org. Chem. 1999, 1787–1893; (d)
Bhalay, G.; Clough, S.; McLaren, L.; Sutherland, A.;
Willis, C. L. J. Chem. Soc., Perkin Trans. 1 2000, 901–910.
24. Collum, D. B.; McDonald, J. H., III; Still, W. C. J. Am.
Chem. Soc. 1980, 102, 2118–2120.
6. (a) Kiegiel, K.; Prokopowicz, P.; Jurczak, J. Synth.
Commun. 1999, 29, 3999–4005; (b) Czapla, A.; Chajewski,
A.; Kiegiel, K.; Bauer, T.; Wielogorski, Z.; Urbanczyk-
Lipkowska, Z.; Jurczak, J. Tetrahedron: Asymmetry 1999,
10, 2101–2111; (c) Raszplewicz, K.; Sikorska, L.; Kiegiel,
K.; Jurczak, J. Pol. J. Chem. 2002, 76, 1595–1600.
7. (a) Aoki, S.; Mikami, K.; Terada, M.; Nakai, T. Tetra-
hedron 1993, 49, 1783–1792; (b) Kwiatkowski, P.; Chała-
daj, W.; Jurczak, J. Tetrahedron Lett. 2004, 45, 5343–
5346.
8. (a) Wang, D.; Wang, Z. G.; Wang, M. W.; Chen, Y. J.;
Liu, L.; Zhu, Y. Tetrahedron: Asymmetry 1999, 10, 327–
338; (b) Ramachandran, P. V.; Krzeminski, M. P.; Reddy,
M. V. R.; Brown, H. C. Tetrahedron: Asymmetry 1999, 10,
11–15.
9. Studies in Natural Products Chemistry; Atta-ur-Rahman,
Ed.; Elsevier: Amsterdam, 1995; Vol. 16.
10. Uchikawa, O.; Okukado, N.; Sakata, T.; Arase, K.;
Terada, K. Bull. Chem. Soc. Jpn. 1988, 61, 2025–2029.