Sequential pericyclic reaction of ene-diallene: synthesis of (±)-estrone

Article abstract of DOI:10.1016/j.tet.2007.10.008

The one-pot construction of perhydrophenanthrene from an acyclic substrate was achieved via a sequential pericyclic reaction, which involved the in situ generation of ene-diallene species due to Myers' propargyl alcohol-allene transformation. The resulting perhydrophenanthrene derivative could be successfully converted into (±)-estrone.

Full text of DOI:10.1016/j.tet.2007.10.008

Tetrahedron 63 (2007) 12639–12645
Sequential pericyclic reaction of ene-diallene:
synthesis of (± ±-estrone
*
Hirohumi Hakuba, Shinji Kitagaki and Chisato Mukai
*
Division of Pharmaceutical Sciences, Graduate School of Natural Science and Technology, Kanazawa University,
Kakuma-machi, Kanazawa 920-1192, Japan
Received 11 September 2007; revised 1 October 2007; accepted 2 October 2007
Available online 6 October 2007
Abstract—The one-pot construction of perhydrophenanthrene from an acyclic substrate was achieved via a sequential pericyclic reaction,
which involved the in situ generation of ene-diallene species due to Myers’ propargyl alcohol–allene transformation. The resulting perhydro-
phenanthrene derivative could be successfully converted into (ꢀ)-estrone.
Ó 2007 Elsevier Ltd. All rights reserved.
1
. Introduction
challenging synthetic reactions. We recently reported the
convenient synthesis of estra-1,3,5(10)-trien-17-one (6)
based on the sequential pericyclic reaction triggered by the
in situ generation of ene-bis(sulfinylallene) species (Scheme
1). Thus, the consecutive sequences, which totally involve
the sulfenic ester formation from bis(propargyl alcohol) 3,
The development of a novel and efficient tandem reaction is
currently the central issue for the synthesis of structurally
complex molecules. The one-pot construction of polycyclic
compounds from acyclic precursors is one of the most
1
S
S
O
PhSCl
O
O
O
Et N
3
HO
THF
PhOS
PhOS
X
X
H
rt → reflux
1
·
·
+
1
. coupling
sulfenate
6π electro-
cyclization
then [4+2]
H
H
2
. deprotection
[2,3]-sigmatropic
rearrangement
OH
5
: X = SOPh
desulfinylation
3
4
6: X = H
OTHP
2
O
SOPh
SOPh
[4+2]
5
4
(Z)-7
SOPh
SOPh
SOPh
O
O
[
1,5]-H
shift
H
SOPh
(
E)-7
8
Scheme 1.
Keywords: Allenes; Tandem reaction; [4+2] Cycloaddition; Estrone.
*
Corresponding authors. Tel.: +81 76 234 4411; fax: +81 76 234 4410; e-mail addresses: kitagaki@p.kanazawa-u.ac.jp; cmukai@kenroku.kanazawa-u.ac.jp
0
040–4020/$ - see front matter Ó 2007 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tet.2007.10.008

12640
H. Hakuba et al. / Tetrahedron 63 (2007) 12639–12645
easily prepared from an aldehyde 1 and enediyne 2, using
benzenesulfenyl chloride (PhSCl) (first step), dual [2,3]-
2. Results and discussion
2
,3
sigmatropic rearrangement of the ester (second step), 6p
electrocyclic reaction of the ene-diallene 4 (third step),
2.1. Pericyclic reaction via generation of unfunctional-
ized ene-diallene by Myers’ allene forming reaction
4
and finally the intramolecular [4+2] cycloaddition of
o-quinodimethane (Z)-7 (fourth step), enabled the one-pot
5
1
The bis(propargyl alcohol) 9 was selected for the initial
stereoselective construction of the steroidal compound 5
from the acyclic substrate. However, the total yield of 6
from 3 involving a desulfinylation step (5 to 6) was poor
evaluation of the in situ generation of the unfunctionalized
ene-diallene derivative using the Myers’ propargyl alcohol–
allene transformation protocol (Table 1). o-Nitrobenzene-
9
(
which have simpler structures than 3, again underwent the
32% yield). Furthermore, it turned out that the substrates,
sulfonylhydrazine (NBSH) was added to a solution of
triphenylphosphine, diethyl azodicarboxylate (DEAD), and
9 in THF at ꢁ15 C. The resulting mixture was kept at the
ꢂ
same temperature for 1 h and then at room temperature for
above mentioned tandem reaction via the intramolecular
[
4+2] cycloaddition to give the corresponding cycloadducts
ꢂ
tion of the perhydrophenanthrene 12 in an unexpectedly
in rather low yields. Interestingly, satisfactory yields could
be obtained when the in situ generated ene-bis(sulfinyl-
allene) species (e.g., 4 without the terminal olefin moiety)
was trapped by the external dienophiles (intermolecular
1 h. Further stirring at 50 C for 1 h resulted in the produc-
low yield (20%) (entry 1). The highest yield (62%) was
ꢂ
observed when the reaction mixture was kept at 50 C for
6
,7
[
4+2] cycloaddition). Thus, these observations indicated
15 h (entry 2). On the other hand, the refluxing temperature
led to a decrease in the yield (entry 3). Tosylhydrazine,
used instead of NBSH, resulted in the production of 12 in
52% yield (entry 4). A similar result was obtained using N-
that the moderate yields of the cycloadducts in the above
mentioned tandem reaction via the intramolecular [4+2]
cycloaddition might be attributed to the nonbonding inter-
action between the phenylsulfinyl group and the methylene
tether of (Z)-7, an essential intermediate for the intramolec-
ular cycloaddition. This would not be the case for the alter-
native intermediate (E)-7 in which the methylene tether is
oriented opposite to the phenylsulfinyl group, although an-
other unfavorable interaction between the exo-methylene
protons and the allylic hydrogens might occur. Indeed, the
sufficient amounts of product 8, which must have been pro-
duced via the [1,5] hydrogen-shift of the intermediate (E)-7,
0
isopropylidene-N -o-nitrobenzenesulfonylhydrazine (IPNBSH),
which was recently reported as an alternative to NBSH by
1
0
Movassaghi and Ahmad (entry 5). It should be stated
that no [1,5] hydrogen-shifted product 13 was detected in
all the reactions. The present method is obviously preferred
1
over the previously developed one (entry 6) from the view-
point of the chemical yield as well as the much simpler
operation.
8
were detected. Thus, we envisaged that the generation of
the ene-diallene species without the phenylsulfinyl group
would make the intramolecular [4+2] cycloaddition process
2.2. Total synthesis of racemic estrone
Encouraged by the improvement in the chemical yield of 12,
1
1
(
in situ generation of the unfunctionalized ene-diallene
fourth step) to occur more easily. We now report the
we embarked on the synthesis of the racemic estrone based
on the newly developed method. Preparation of the cyclo-
pentane derivative, the D-ring unit of estrone having a
dienophile part, commenced with the stereoselective
4
c,d,f–j
species
the racemic estrone.
and its application to the total synthesis of
Table 1. Sequential reaction of bis(propargyl alcohol) 9
HO
H
H
·
·
9
OH
10
11
12
13
Entry Conditions
Yield of Yield of
2 (%) 13 (%)
1
ꢂ
ꢂ
a
1
2
3
4
5
6
PPh
PPh
PPh
PPh
PPh
3
3
3
3
3
(5 equiv), DEAD (5 equiv), o-NO
2
C
6
H
4
SO
2
NHNH
2
(NBSH) (5 equiv), THF, ꢁ15 C/rt/50 C
20
62
46
52
—
—
—
—
—
33
ꢂ
ꢂ
b
(5 equiv), DEAD (5 equiv), NBSH (5 equiv), THF, ꢁ15 C/rt/50 C
ꢂ
(5 equiv), DEAD (5 equiv), NBSH (5 equiv), THF, ꢁ15 C/rt/reflux
ꢂ
(5 equiv), DEAD (5 equiv), TsNHNH
2
(5 equiv), benzene, 5 C/rt then MeOH, reflux
ꢂ
(5 equiv), DEAD (5 equiv), o-NO
2
C
6
H
4
SO
2
NHN]C(CH
3
)
2
(IPNBSH) (5 equiv), THF, rt then TFE–H
2
O (1:1), 50 C 48
46
c
(1) PhSCl (6 equiv), Et
3
N, (7 equiv), THF, rt/reflux
(
(
2) m-CPBA, CH Cl
2
3) Mg, MeOH, 50 C
2
ꢂ
a
b
c
ꢂ
Reaction performed for 1 h at 50 C.
ꢂ
SO2Ph
Reaction performed for 15 h at 50 C.
0
Yield of 13 obtained by m-CPBA oxidation after sequential pericyclic reaction.
O
SO Ph
2
13'

H. Hakuba et al. / Tetrahedron 63 (2007) 12639–12645
12641
introduction of the C -unit (t-butyl acrylate) to the known
3
The synthesis of the enediyne unit 21 was performed
as follows. The successive Sonogashira reaction of the
known ethyl (Z)-dibromopropenoate (18), reduction, and
1
2
2
-methyl-3-vinylcyclopentanone (14) to produce 15 in
1
3
15
6
ketone carbonyl group of 15 with sodium borohydride,
6% yield (Scheme 2). Stereoselective reduction of the
1
4
the Sonogashira reaction furnished the enediynol 19.
Dess–Martin oxidation and subsequent addition of methyl-
lithium to the resulting aldehyde furnished the secondary
alcohol 20, which was subsequently converted into 21 by
protection of the hydroxy group with methyl iodide and re-
moval of the terminal trimethylsilyl group. The coupling re-
action of these two components 17 and 21 was realized by
the addition of the acetylide, derived from 21, to the alde-
hyde 17 to provide, after desilylation, the ene-bis(propargyl
and methylation of the resulting alcohol was followed by
reduction of the ester functionality with DIBAL-H to afford
the aldehyde 17.
O
O
OMe
a
b,c
tBuO C
tBuO C
2
2
1
6
alcohol) 22 as an inseparable mixture of diastereoisomers.
14
15
16
With the substrate for the sequential pericyclic reaction in
hand, the aforementioned procedures for the preparation of
12 were examined. As a result, Movassaghi’s protocol
showed the best result for the transformation of 22 into 23.
OMe
d
OHC
Thus, the treatment with IPNBSH under Mitsunobu con-
ditions and subsequent exposure to TFE–H O at 50 C
ꢂ
furnished the desired polycyclic compound 23 as an insepa-
2
1
7
1
7
TMS
TMS
rable mixture of two diastereomers in 38% yield. The
selective demethylation of the benzyl alcohol moiety using
nitric acid and Dess–Martin oxidation produced the
Br
Br
e-g
h,i
1
8
HO
EtO C
2
methyl ketone 24, which was exposed to m-CPBA in the
presence of scandium triflate to afford the acetate 25.
Deprotection of the hydroxyl group on the D-ring was fol-
lowed by the consecutive Jones’ oxidation and deacetylation
to provide the (ꢀ)-estrone (26).
OH
19,20
18
TBSO
19
TBSO
20
OMe
j,k
HO
3. Conclusion
l,m
MeO
MeO
WehaveshownthatMyers’propargyl alcohol–allenetransfor-
mation protocol could be applicable to the sequential reaction
of ene-bis(propargyl alcohols) leading to polycyclic
compounds, and our method effected the total synthesis of
TBSO
OH
2
2
21
(
ꢀ)-estrone. The present method would provide a new synthe-
n
sis route for the (+)-estrone, because some enantioselective
syntheses of (3S)-2-methyl-3-vinylcyclopentanone and its re-
lated compounds (D-ring unit) have already been reported.
OMe
OMe
2
1
H
H
o-q
H
H
H
H
MeO
O
4. Experimental
23
24
4.1. General
r
O
OMe
Melting points are uncorrected. IR spectra were measured in
CHCl . H NMR and C NMR spectra were recorded on
1
13
3
s-u
H
H
1
a 500 MHz spectrometer. H NMR spectra were taken in
CDCl . CHCl (7.26 ppm) for silyl compounds and tetra-
H
H
H
H
3
3
HO
AcO
methylsilane (0.00 ppm) for compounds without a silyl
group were used as internal standards. C NMR spectra
26
25
13
were recorded in CDCl with CDCl (77.00 ppm) as an inter-
3
Scheme 2. Reagents and conditions: (a) t-BuOK, CH
(66%); (b) NaBH
2
]CHCO t-Bu, THF
2
3
4
, MeOH; (c) 2,6-di-t-butylpyridine, MeOTf, CH
ꢂ
2
Cl
2
nal standard. All reactions were carried out under a nitrogen
atmosphere. Silica gel (silica gel 60, 230–400 mesh) was
used for chromatography. Organic extracts were dried over
anhydrous Na SO .
(
60% from 15); (d) DIBAL-H, toluene, ꢁ78 C (70%); (e) HC^CTMS,
ꢂ
Pd(PPh
3
)
4
, CuI, i-Pr
2
NEt, DMF; (f) DIBAL-H, toluene, ꢁ78 C; (g)
ꢂ
HC^CCH
18); (h) Dess–Martin periodinane, CH
from 19); (j) NaH, MeI, THF, 0/50 C; (k) K
2
OTBS, Pd(PPh
3
)
4
, CuI, n-BuNH , benzene, 50 C (40% from
Cl ; (i) MeLi, Et
2
2
ꢂ
2
2
O, ꢁ78 C (51%
2
4
ꢂ
ꢂ
2
CO
3
, MeOH, 0 C/rt
ꢂ
ꢂ
(
(
71% from 20); (l) n-BuLi, 17, THF, ꢁ78 C; (m) TBAF, THF, 0 C
4.2. Sequential pericyclic reaction of ene-bis(propargyl
alcohol± 9
61% from 21); (n) PPh
3
, DEAD, IPNBSH, THF, rt then TFE–H
2
O (1:1),
O, 50 C; (q)
ꢂ
ꢂ
5
0 C (38%); (o) HNO
3
, CH
Cl
, EtSH; (t) CrO
2
Cl
2
; (p) NaOH, THF–H
2
Dess–Martin periodinane, CH
CH Cl (64%); (s) AlBr
MeOH (89% from 25).
2
2
(72% from 23); (r) m-CPBA, Sc(OTf)
, H SO , acetone; (u) K CO
3
,
,
4.2.1. Sequential pericyclic reaction with NBSH (Table 1,
entry 2±. To a solution of PPh (156 mg, 0.596 mmol) in
2
2
3
3
2
4
2
3
3

12642
H. Hakuba et al. / Tetrahedron 63 (2007) 12639–12645
THF (3.0 mL) was added 40% DEAD in toluene (0.30 mL,
0
the mixture was refluxed for 12 h. After cooling, the reaction
was quenched by addition of 10% aqueous HCl. The organic
layer was separated, washed with saturated aqueous
ꢂ
0 min at that temperature. A solution of bis(propargyl alco-
.60 mmol) at ꢁ15 C, and the mixture was stirred for
1
hol) 9 (26.0 mg, 0.119 mmol) in THF (5.0 mL) was added to
NaHCO , water and brine, dried, and concentrated to dry-
3
ꢂ
tion of NBSH (129 mg, 0.596 mmol) was added, and the
the mixture, which was stirred for 2.5 h at ꢁ15 C. A solu-
ness. Chromatography of the residue with hexane–AcOEt
(10:1) afforded 16 (115 mg, 60% for two steps) as a colorless
ꢂ
for 15 h at 50 C. The reaction was quenched by addition
ꢁ1
1
mixture was stirred for 10 h at ꢁ15 C, 1 h at rt, and then
oil. IR 1720 cm ; H NMR d 5.72 (1H, ddd, J¼16.5, 10.4,
7.9 Hz), 5.00–4.96 (2H, m), 3.34 (1H, t, J¼7.9 Hz), 3.28
(3H, s), 2.35–2.22 (2H, m), 2.11 (1H, dd, J¼18.3, 8.5 Hz),
2.04–1.97 (1H, m), 1.72–1.49 (5H, m), 1.43 (9H, s), 0.73
ꢂ
of water, and the mixture was extracted with AcOEt. The
extract was washed with water and brine, dried, and con-
centrated to dryness. Chromatography of the residue with
hexane gave perhydrophenanthrene (13.5 mg, 62%) as a
colorless oil.
1
3
(3H, s); C NMR d 173.9, 138.9, 115.6, 88.3, 79.8, 57.3,
50.7, 45.8, 34.8, 30.7, 28.1, 27.0, 25.8, 12.9; FABMS m/z
269 (M +1, 12); HRFABMS calcd for C H O
+
1
6
29
3
2
69.2117, found 269.2111.
4
(
9
.2.2. Sequential pericyclic reaction with tosylhydrazine
Table 1, entry 4±. To a solution of bis(propargyl alcohol)
(20.9 mg, 0.096 mmol) in benzene (1.0 mL) were succes-
4.3.3. 3-[(1R*,2R*,5R*±-2-Methoxy-1-methyl-5-vinyl-
cyclopentyl]propanal (17±. To a solution of 16 (115 mg,
0.430 mmol) in toluene (8.0 mL) was added DIBAL-H in
sively added PPh3 (126 mg, 0.479 mmol), 40% DEAD
in toluene (0.24 mL, 0.48 mmol), and tosylhydrazine
ꢂ
hexane (1.0 M, 0.52 mL, 0.52 mmol) at ꢁ78 C, and the
ꢂ
(
89.2 mg, 0.479 mmol) at 5 C. After being stirred for 1 h
mixture was stirred for 1 h at that temperature. The reaction
was quenched by addition of water, and the mixture was di-
luted with AcOEt, filtered through a short pad of Celite, and
concentrated to dryness. Chromatography of the residue
with hexane–AcOEt (5:1) afforded 17 (59 mg, 70%) as a
at that temperature, the mixture was concentrated to dryness.
The residue was taken up to MeOH (5.0 mL) and refluxed
for 3 h. After cooling, the reaction mixture was diluted
with water and extracted with AcOEt. The extract was
washed with water and brine, dried, and concentrated to
dryness. Chromatography of the residue with hexane gave
perhydrophenanthrene (9.3 mg, 52%) as a colorless oil.
ꢁ1 1
colorless oil. IR 1720 cm ; H NMR d 9.75 (1H, s), 5.71
(1H, ddd, J¼17.1, 9.2, 8.5 Hz), 5.01 (1H, d, J¼9.2 Hz),
4.98 (1H, d, J¼17.1 Hz), 3.31 (1H, t, J¼8.6 Hz), 3.25 (3H,
s), 2.62–2.55 (1H, m), 2.49–2.46 (1H, m), 2.11 (1H, dd,
J¼10.4, 8.5 Hz), 2.06–1.99 (1H, m), 1.73–1.42 (5H, m),
4
4
.3. Synthesis of estrone
1
3
0
.74 (3H, s); C NMR d 203.0, 138.7, 115.9, 88.1, 57.1,
.3.1. t-Butyl 3-[(1R*,5R*±-1-methyl-2-oxo-5-vinylcyclo-
50.9, 45.6, 39.2, 31.5, 26.8, 25.7, 12.7; FABMS m/z 197
(M +1, 6.5); HRFABMS calcd for C H O 197.1542,
found 197.1546.
+
pentyl]propanoate (15±. To a solution of 2-methyl-3-vinyl-
cyclopentanone (745 mg, 6.00 mmol) in THF (12 mL) was
added t-BuOK (135 mg, 1.20 mmol) at room temperature,
and the mixture was stirred for 30 min. A solution of t-butyl
acrylate (1.14 g, 9.00 mmol) in THF (8 mL) was added and
the resulting mixture was stirred for 15 h. The reaction was
1
5 21 2
4.3.4. (E±-7-(t-Butyldimethylsiloxy±-4-hydroxymethyl-1-
(trimethylsilyl±hept-3-ene-1,5-diyne (19±. To a solution
of 18 (2.04 g, 7.91 mmol), trimethylsilylacetylene (1.90 mL,
13.4 mmol), Pd(PPh3)4 (512 mg, 0.443 mmol), and CuI
quenched by addition of saturated aqueous NH Cl, and the
4
mixture was extracted with AcOEt. The extract was washed
with water and brine, dried, and concentrated to dryness.
Chromatography of the residue with hexane–AcOEt (5:1) af-
(301 mg, 1.58 mmol) in DMF (45 mL) was added i-Pr NEt
2
(2.05 mL, 13.1 mmol) at 0 C, and the mixture was stirred
ꢂ
for 11 h at that temperature. The reaction was quenched by
ꢁ
1
forded 15 (986 mg, 66%) as a colorless oil. IR 1724 cm
;
addition of saturated aqueous NH Cl, and the mixture was
4
1
H NMR d 5.75–5.68 (1H, m), 5.08–5.05 (2H, m), 2.55–
.50 (1H, m), 2.35–2.29 (1H, m), 2.27–1.95 (4H, m),
extracted with AcOEt. The extract was washed with water
and brine, dried, and concentrated to dryness. The residue
was passed through a short pad of silica gel with hexane–
AcOEt (10:1) to afford the crude enyne (1.86 g) as a brown
oil. To a solution of the above enyne (1.86 g) in toluene
2
1
3
1
d 221.7, 172.6, 136.9, 116.7, 80.1, 50.6, 48.2, 36.8, 30.5,
30.3, 28.0, 24.3, 17.3; MS m/z 252 (M , 38); HRMS calcd
for C H O 252.1726, found 252.1730.
.78–1.60 (3H, m), 1.36 (9H, s), 0.79 (3H, s); C NMR
+
(10 mL) was added dropwise DIBAL-H in hexane (1.0 M,
1
1
5 24 3
ꢂ
5 mL, 15 mmol) at ꢁ78 C, and the mixture was stirred
ꢂ
4.3.2. t-Butyl 3-[(1R*,2R*,5R*±-2-methoxy-1-methyl-5-
vinylcyclopentyl]propanoate (16±. To a solution of 15
for 30 min at that temperature and then for 30 min at 0 C.
The reaction was quenched by addition of 10% aqueous
HCl, and the mixture was extracted with AcOEt. The extract
was washed with water and brine, dried, and concentrated to
dryness. The residue was passed through a short pad of silica
gel with hexane–AcOEt (7:1) to afford the crude alcohol
(930 mg) as a yellow oil. To a solution of the above alcohol
(930 mg) in benzene (10 mL) were successively added
3-(t-butyldimethylsiloxy)-1-butyne (1.36 g, 7.98 mmol),
Pd(PPh3)4 (231 mg, 0.199 mmol), CuI (152 mg,
(
181 mg, 0.715 mmol) in MeOH (5.0 mL) was added
ꢂ
NaBH (135 mg, 3.58 mmol) at ꢁ78 C, and the mixture
4
was stirred for 30 min at that temperature. The reaction
was quenched by addition of water, and the mixture was ex-
tracted with AcOEt. The extract was washed with water and
brine, dried, and concentrated to dryness. The residue was
passed through a short pad of silica gel with hexane–AcOEt
(
3:1) to afford the crude cyclopentanol (182 mg) as a color-
less oil. To a solution of the above cyclopentanol (182 mg) in
CH Cl (5.0 mL) were successively added a solution of 2,6-
di-t-butylpyridine (682 mg, 3.57 mmol) in CH Cl (1.0 mL)
0.798 mmol), and n-BuNH (0.80 mL, 8.0 mmol) at room
2
temperature, and the mixture was stirred for 6 h at 60 C.
ꢂ
After cooling, the reaction was quenched by addition of
2
2
2
2
and MeOTf (242 mL, 2.14 mmol) at room temperature, and
saturated aqueous NH Cl, and the mixture was extracted
4

H. Hakuba et al. / Tetrahedron 63 (2007) 12639–12645
12643
ꢂ
with AcOEt. The extract was washed with water and brine,
dried, and concentrated to dryness. Chromatography of the
residue with hexane–AcOEt (5:1) afforded 19 (1.02 g,
0.24 mL, 0.38 mmol) at ꢁ78 C, and the mixture was stirred
for 1 h at that temperature. A solution of 17 (33.0 mg,
0.168 mmol) was added to the mixture, which was further
ꢂ
4
2
0% for three steps) as a brown oil. IR 3603, 3421,
133 cm ; H NMR d 5.97 (1H, s), 4.52 (2H, s), 4.17
stirred for 30 min at ꢁ78 C. The reaction was quenched
ꢁ
1 1
by addition of water, and the mixture was extracted with
AcOEt. The extract was washed with water and brine, dried,
and concentrated to dryness. The residue was passed through
a short pad of silica gel with hexane–AcOEt (3:1) to afford
the crude alcohol (50.0 mg) as a yellow oil. To a solution
of the above alcohol (50.0 mg) in THF (1.0 mL) was added
(
(
2H, s), 1.94 (1H, br s), 0.91 (9H, s), 0.20 (9H, s), 0.14
6H, s); C NMR d 134.8, 114.1, 102.0, 96.8, 81.0, 64.9,
1
3
+
5
HRMS calcd for C H O Si 322.1784, found 322.1788.
2.2, 25.8, 18.3, ꢁ0.1, ꢁ5.0; MS m/z 322 (M , 5.9);
1
7
30
2
2
ꢂ
4
1
.3.5. (E±-7-(t-Butyldimethylsiloxy±-4-(1-hydroxyethyl±-
-(trimethylsilyl±hept-3-ene-1,5-diyne (20±. To a solution
TBAF in THF (1.0 M, 0.12 mL, 0.12 mmol) at 0 C. After
1 h, the reaction mixture was diluted with water and ex-
tracted with AcOEt. The extract was washed with water
and brine, dried, and concentrated to dryness. Chromato-
graphy of the residue with hexane–AcOEt (3:2) afforded
22 (36.7 mg, 61% for two steps) as an inseparable mixture
of diastereomers in a ratio of ca. 1:1 as a yellow oil. IR
of 19 (567 mg, 1.76 mmol) in CH Cl (6.0 mL) was added
2
2
ꢂ
Dess–Martin periodinane (895 mg, 2.11 mmol) at 0 C,
and the mixture was stirred for 1 h at room temperature.
The reaction was quenched by addition of saturated aqueous
Na S O , and the mixture was extracted with AcOEt. The
2
2 3
ꢁ1 1
extract was washed with water and brine, dried, and concen-
trated to dryness. The residue was passed through a short pad
of silica gel with hexane–AcOEt (6:1) to afford the crude al-
dehyde (400 mg) as a brown oil. To a solution of the above
3603, 3400 cm ; H NMR d 5.90 (1H, s), 5.73 (1H, ddd,
J¼17.1, 10.4, 8.5 Hz), 5.01 (1H, d, J¼10.4 Hz), 4.99 (1H,
d, J¼17.1 Hz), 4.51 (1H, dd, J¼11.0, 4.9 Hz), 4.47 (2H,
s), 3.79 (1H, q, J¼6.1 Hz), 3.42, 3.40 (total 1H, each t, J¼
7.9 Hz), 3.32, 3.31 (total 3H, each s), 3.28 (3H, s), 2.94
(1H, br s), 2.18 (1H, q, J¼8.6 Hz), 2.05–2.00 (1H, m),
1.84–1.42 (8H, m), 1.34 (3H, d, J¼6.1 Hz), 0.77 (3H, s);
aldehyde (400 mg) in Et O (12 mL) was added MeLi in
2
ꢂ
was stirred for 10 min at that temperature. The reaction was
Et O (1.0 M, 1.4 mL, 1.4 mmol) at ꢁ78 C, and the mixture
2
1
3
quenched by addition of saturated aqueous NH Cl, and the
4
C NMR d 139.1, 139.0, 136.5, 136.4, 115.6, 115.5,
mixture was extracted with AcOEt. The extract was washed
with water and brine, dried, and concentrated to dryness.
Chromatography of the residue with hexane–AcOEt (3:1) af-
forded 20 (299 mg, 51% for two steps) as a brown oil. IR
115.0, 114.9, 97.5, 97.4, 96.7, 96.6, 87.8, 87.6, 82.12,
82.11, 81.7, 81.6, 79.4, 63.7, 63.6, 57.4, 57.3, 56.6, 51.4,
51.3, 49.9, 49.7, 49.6, 45.9, 34.4, 34.2, 32.4, 26.9, 26.8,
+
25.7, 25.6, 20.8, 13.7, 13.6; MS m/z 360 (M , 7.5); HRMS
calcd for C H O 360.2301, found 360.2314.
ꢁ
1 1
3
4
6
587, 2141 cm ; H NMR d 5.95 (1H, s), 4.51 (2H, s),
.29 (1H, q, J¼6.7 Hz), 2.33 (1H, br s), 1.34 (3H, d, J¼
2
2 32 4
1
3
.7 Hz), 0.89 (9H, s), 0.18 (9H, s), 0.12 (6H, s); C NMR
4.3.8. 17-Methoxy-3-(1-methoxyethyl±estra-1,3,5(10±-tri-
ene (23±. To a solution of 22 (13.0 mg, 3.60ꢃ10 mmol)
ꢁ2
d 139.6, 113.5, 102.2, 101.8, 97.4, 80.8, 70.0, 52.1, 25.8,
2.5, 18.2, ꢁ0.2, ꢁ5.1; MS m/z 336 (M , 6.6); HRMS calcd
+
2
for C H O Si 336.1941, found 336.1945.
in THF (0.4 mL) were successively added PPh (94.4 mg,
3
0.360 mmol), IPNBSH (92.6 mg, 0.360 mmol), and DEAD
ꢂ
18
32
2
2
in 40% toluene (0.16 mL, 0.36 mmol) at 0 C. After 5 min,
4.3.6. (E±-7-(t-Butyldimethylsiloxy±-4-(1-methoxyethyl±-
hept-3-ene-1,5-diyne (21±. To a solution of 20 (299 mg,
the reaction mixture was allowed to warm to room tempera-
ture. After 3 h, the mixture was diluted with THF (2.0 mL),
and TFE–H O (1:1, 1.0 mL) was added. After being stirred
0
.891 mmol) in THF (8.0 mL) was added NaH (60% in
ꢂ
2
ꢂ
oil, 42.8 mg, 1.1 mmol) at 0 C, and the mixture was stirred
for 5 min at that temperature. MeI (0.11 mL, 1.8 mmol) was
for 12 h at 50 C, the reaction mixture was partitioned be-
tween hexane and water. The aqueous layer was extracted
with hexane, and the combined extracts were washed with
water and brine, dried, and concentrated to dryness. Chro-
matography of the residue with hexane–AcOEt (5:1) af-
forded 23 (4.5 mg, 38%) as an inseparable mixture of two
diastereomers (ratio not determined) as a colorless oil.
ꢂ
The reaction was quenched by addition of saturated aqueous
added and the resulting mixture was stirred for 12 h at 50 C.
NH Cl, and the mixture was extracted with AcOEt. The
4
extract was washed with water and brine, dried, and con-
centrated to dryness. The residue was dissolved in MeOH
ꢁ
1 1
(
0
5.0 mL) and K CO (124 mg, 0.900 mmol) was added at
2
C. After being stirred for 1 h at room temperature, the re-
IR 3007, 2932 cm ; H NMR d 7.26–7.24 (1H, m), 7.07–
7.04 (1H, m), 6.99 (1H, d, J¼4.2 Hz), 4.21 (1H, q, J¼
6.4 Hz), 3.36 (3H, s), 3.30 (1H, t, J¼8.1 Hz), 3.21 (3H, s),
2.86–2.84 (2H, m), 2.32–2.29 (1H, m), 2.25–2.20 (1H, m),
2.06–2.03 (2H, m), 1.89–1.86 (1H, m), 1.72–1.30 (7H, m),
1.41 (3H, d, J¼6.4 Hz), 1.23–1.17 (1H, m), 0.78 (3H, s);
3
ꢂ
action mixture was diluted with water and extracted with
AcOEt. The extract was washed with water and brine, dried,
and concentrated to dryness. Chromatography of the residue
with hexane–AcOEt (6:1) afforded 21 (213 mg, 71% for two
ꢁ1 1
13
steps) as a brown oil. IR 3304 cm ; H NMR d 5.85 (1H, s),
.52 (2H, s), 3.76 (1H, q, J¼6.1 Hz), 3.26 (3H, s), 3.24 (1H,
d, J¼2.4 Hz), 1.31 (3H, d, J¼6.1 Hz), 0.90 (9H, s), 0.13 (6H,
C NMR d 140.6, 139.6, 136.8, 136.7, 126.8, 126.7,
4
125.4, 125.3, 123.5, 123.4, 90.8, 79.5, 79.4, 57.9, 56.4,
50.5, 44.4, 43.2, 38.4, 38.3, 38.1, 29.6, 29.5, 27.8, 27.2,
26.2, 23.8, 23.7, 23.1, 11.5; MS m/z 328 (M , 100);
1
3
+
s); C NMR d 138.3, 113.4, 97.0, 83.7, 80.7, 79.4, 56.6, 52.2,
+
2
calcd for C H O Si 278.1702, found 278.1715.
5.8, 20.8, 18.2, ꢁ5.08, ꢁ5.09; MS m/z 278 (M , 71); HRMS
HRMS calcd for C H O 328.2402, found 328.2407.
2 32 2
2
1
6 26 2
4
.3.9. 3-Acetyl-17-methoxyestra-1,3,5(10±-triene (24±. To
ꢁ2
4
.3.7. (E±-10-[(1R*,2R*,5R*±-2-Methoxy-1-methyl-5-vi-
nylcyclopentyl]-4-(1-methoxyethyl±dec-4-ene-2,6-diyne-
,8-diol (22±. To a solution of 21 (106 mg, 0.381 mmol)
in THF (2.0 mL) was added n-BuLi in hexane (1.56 M,
a solution of 23 (11.3 mg, 3.44ꢃ10 mmol) in CH Cl
2
2
(1.0 mL) was added fuming HNO (14 mL, 0.34 mmol) at
3
ꢂ
temperature. The mixture was diluted with 10% aqueous
1
0 C, and the reaction mixture was stirred for 24 h at room

12644
H. Hakuba et al. / Tetrahedron 63 (2007) 12639–12645
Na SO and extracted with AcOEt. The extract was washed
2
After being stirred for 30 min, the reaction mixture was
diluted with water and extracted with AcOEt. The extract
was washed with water and brine, dried, and concentrated
to dryness. The residue was passed through a short pad of sil-
ica gel with hexane–AcOEt (3:1) to afford the crude ketone
(8.3 mg) as a colorless solid. To a solution of the above ke-
tone (8.3 mg) in MeOH (1.0 mL) was added K CO (3.8 mg,
4
with water and brine, dried, and concentrated to dryness. The
residue was passed through a short pad of silica gel with
hexane–AcOEt (5:1) to afford the crude nitrate (9.5 mg) as
a colorless oil. To a solution of the above nitrate (9.5 mg)
in THF (1.0 mL) was added 10% aqueous NaOH (1.0 mL)
ꢂ
at room temperature. After being stirred for 6 h at 50 C,
2
3
the mixture was diluted with water and extracted with
AcOEt. The extract was washed with water and brine, dried,
and concentrated to dryness. The residue was passed through
a short pad of silica gel with hexane–AcOEt (3:1) to afford
the crude alcohol (7.9 mg) as a colorless oil. To a solution
of the above alcohol (7.9 mg) in CH Cl (1.0 mL) was added
0.038 mmol) at room temperature. After being stirred for
1 h, the reaction mixture was diluted with water and ex-
tracted with AcOEt. The extract was washed with water
and brine, dried, and concentrated to dryness. Chromato-
graphy of the residue with hexane–AcOEt (3:1) afforded
26 (7.2 mg, 89% for three steps) as colorless crystals. Mp
2
2
ꢂ
ꢁ1
255–257 C (CH Cl –hexane); IR 3595, 1734 cm ; H
2 2
1
Dess–Martin periodinane (10.3 mg, 0.184 mmol) at room
temperature, and the mixture was stirred for 3 h. The reac-
tion was quenched by addition of saturated aqueous
Na S O , and the mixture was extracted with AcOEt. The
NMR d 7.15 (1H, d, J¼8.5 Hz), 6.64 (1H, dd, J¼8.5,
2.4 Hz), 6.58 (1H, d, J¼2.4 Hz), 4.67 (1H, br s), 2.89–2.85
(2H, m), 2.50 (1H, dd, J¼18.9, 8.5 Hz), 2.40–2.34 (1H,
m), 2.28–2.21 (1H, m), 2.18–1.92 (4H, m), 1.68–1.39 (6H,
2
2 3
extract was washed with water and brine, dried, and con-
centrated to dryness. Chromatography of the residue with
hexane–AcOEt (5:1) afforded 24 (7.6 mg, 72% for three
1
3
m), 0.91 (3H, s); C NMR d 221.0, 153.5, 138.1, 132.1,
126.5, 115.3, 112.9, 50.4, 48.0, 44.0, 38.4, 35.9, 31.6,
ꢂ
+
steps) as colorless needles. Mp 125–127 C (acetone–
hexane); IR 1678 cm
29.5, 26.5, 25.9, 21.6, 13.9; MS m/z 270 (M , 94.1);
HRMS calcd for C H O 270.1620, found 270.1617.
ꢁ1
1
;
H NMR d 7.70 (1H, d, J¼
1
8 22 2
7
3
2
1
1
4
.9 Hz), 7.65 (1H, s), 7.36 (1H, d, J¼7.9 Hz), 3.36 (3H, s),
.30 (1H, t, J¼7.9 Hz), 2.91–2.88 (2H, m), 2.55 (3H, s),
.33–2.22 (2H, m), 2.08–2.03 (2H, m), 1.92–1.89 (1H, m),
Acknowledgements
1
3
.69–1.19 (8H, m), 0.78 (3H, s); C NMR d 198.2, 146.2,
37.1, 134.7, 128.9, 125.7, 125.6, 90.7, 57.9, 50.5, 44.7,
3.1, 38.1, 38.0, 29.5, 27.7, 27.0, 26.5, 26.1, 23.1, 11.5;
This work was supported in part by a Grant-in-Aid for
Scientific Research from the Ministry of Education, Culture,
Sports, Science, and Technology, Japan, for which we are
thankful.
+
MS m/z 312 (M , 100); HRMS calcd for C H O
2
1
28
2
3
12.2089, found 312.2089.
4
.3.10. 3-Acetoxyl-17-methoxyestra-1,3,5(10±-triene (25±.
ꢁ
3
To a solution of 24 (2.9 mg, 9.3ꢃ10 mmol) in CH Cl
References and notes
2
2
(
1.0 mL) were added m-CPBA (7.8 mg, 0.045 mmol) and
ꢁ
3
Sc(OTf) (1.0 mg, 2.0ꢃ10 mmol) at room temperature,
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3
and the mixture was stirred for 4 days. The reaction was
quenched by addition of saturated aqueous Na S O , and
2. Horner, L.; Binder, V. Liebigs Ann. Chem. 1972, 757, 33–68.
3. The tandem formation and intramolecular [4+2] cycloaddition
of 1-sulfinyl-1-vinylallenes, triggered by [2,3]-sigmatropic
rearrangement of the corresponding propargyl sulfenates,
have been reported: (a) Okamura, W. H.; Curtin, M. L.
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2
2 3
the mixture was extracted with AcOEt. The extract was
washed with water and brine, dried, and concentrated to dry-
ness. Chromatography of the residue with hexane–AcOEt
(
7
5:1) afforded 25 (1.9 mg, 64%) as colorless crystals. Mp
ꢂ
ꢁ1
1
0–73 C (CH Cl –hexane); IR 1749 cm
2
;
H NMR
2
d 7.26 (1H, d, J¼8.3 Hz), 6.83 (1H, d, J¼8.3 Hz), 6.77
(
(
(
1H, s), 3.36 (3H, s), 3.30 (1H, t, J¼8.1 Hz), 2.84–2.82
2H, m), 2.28–2.17 (2H, m), 2.05–2.03 (2H, m), 1.87–1.84
1H, m), 1.70–1.65 (1H, m), 1.53–1.16 (7H, m), 0.77 (3H,
1
3
s); C NMR d 169.8, 148.4, 138.2, 138.0, 126.3, 121.4,
1
2
18.5, 90.7, 57.8, 50.3, 44.1, 43.1, 38.2, 38.0, 29.5, 27.7,
7.0, 26.2, 23.0, 21.2, 11.5; MS m/z 328 (M , 100);
+
HRMS calcd for C H O 328.2039, found 328.2039.
1 28 3
2
4
1
0
.3.11. Estrone (26±. To a solution of 25 (10.0 mg, 3.04ꢃ
ꢁ
3
2
0
mmol) in EtSH (1.0 mL) was added AlBr (20.3 mg,
.152 mmol) at room temperature, and the mixture was
stirred for 30 min. The reaction was quenched by addition
of water, and the mixture was extracted with AcOEt. The
extract was washed with water and brine, dried, and con-
centrated to dryness. The residue was passed through a short
pad of silica gel with hexane–AcOEt (3:1) to afford the crude
alcohol (8.5 mg) as a colorless solid. To a solution of the
above alcohol (8.5 mg) in acetone (1.0 mL) was added
5. (a) Segura, J. L.; Martin, N. Chem. Rev. 1999, 99, 3199–3246;
(b) Martin, N.; Seoane, C.; Hanack, M. Org. Prep. Proced. Int.
1991, 23, 237–272; (c) Charlton, J. L.; Alauddin, M. M.
0
concd H SO (1 mL) in water (1 mL)] at room temperature.
.5 mL of Jones reagent [CrO (200 mg, 2.00 mmol) and
3
2
4

H. Hakuba et al. / Tetrahedron 63 (2007) 12639–12645
12645
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1
6
7
1
996, 52, 6453–6518.
0
8
. [1,5] Hydrogen-shifted product was isolated as 8 in 29% yield
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SO Ph
2
O
1
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SO Ph
2
8'
2
3, 2603–2604.
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1
9
. (a) Myers, A. G.; Zheng, B. J. Am. Chem. Soc. 1996, 118, 4492–
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1 13
were detected in a ratio of ca. 1:1 by H and C NMR analyses.
17. The diastereomer ratio was not determined.
4
1
1
1
18. Strazzolini, P.; Runcio, A. Eur. J. Org. Chem. 2003, 526–536.
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5
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(
1
j) Tietze, L. F.; N €o bel, T.; Spescha, M. J. Am. Chem. Soc.
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