Preparation of optically pure propargylic and allylic alcohols from 2-(trimethylsilyl)vinyl sulfoxides as a chiral ethynyl anion synthon: Computational studies on elimination reaction of 2-(trimethylsilyl)vinyl sulfoxides

Article abstract of DOI:10.1021/jo0157223

The reaction of the (α-carbanion derived from (trimethylsilyl)vinyl sulfoxides with aldehydes afforded a diastereomeric mixture of the products. Each diastereomer was subjected to specific elimination reactions to give optically pure propargylic, trimethylsilylated propargylic, and allylic alcohols. Acceleration of the sulfenic acid-elimination from the β-silylvinyl sulfoxide was demonstrated by the ab initio calculation to be ascribed mainly to the β-effect of the silyl group.

Full text of DOI:10.1021/jo0157223

640
J . Org. Chem. 2002, 67, 640-647
P r ep a r a tion of Op tica lly P u r e P r op a r gylic a n d Allylic Alcoh ols
fr om 2-(Tr im eth ylsilyl)vin yl Su lfoxid es a s a Ch ir a l Eth yn yl An ion
Syn th on : Com p u ta tion a l Stu d ies on Elim in a tion Rea ction of
2-(Tr im eth ylsilyl)vin yl Su lfoxid es
Shuichi Nakamura, Shinya Kusuda, Kiyoshi Kawamura, and Takeshi Toru*
Department of Applied Chemistry, Nagoya Institute of Technology, Gokiso, Showa-ku,
Nagoya 466-8555, J apan
toru@ach.nitech.ac.jp
Received May 1, 2001
The reaction of the R-carbanion derived from (trimethylsilyl)vinyl sulfoxides with aldehydes afforded
a diastereomeric mixture of the products. Each diastereomer was subjected to specific elimination
reactions to give optically pure propargylic, trimethylsilylated propargylic, and allylic alcohols.
Acceleration of the sulfenic acid-elimination from the â-silylvinyl sulfoxide was demonstrated by
the ab initio calculation to be ascribed mainly to the â-effect of the silyl group.
In tr od u ction
carbanions derived from â-(trimethylsilyl)ethyl sulfoxides
with aldehydes proceeded with extremely high stereo-
selectivity on the face of the carbanion R to the sulfinyl
group. This reaction provides a convenient method for
the preparation of optically pure allylic alcohols via
subsequent elimination of the sulfinyl and the silyl
groups.5 To develop a new chiral ethynyl anion equiva-
lent, we studied the reaction of R-lithio (trimethylsilyl)-
vinyl p-tolyl sulfoxide with aldehydes, followed by easy
elimination of the sulfinyl group by the action of the
adjacent trimethylsilyl group.6 This methodology would
provide the asymmetric synthesis of both enantiomers
of propargylic alcohols. We now report in detail (1) the
addition of (trialkylsilyl)vinyl sulfoxides with various
aldehydes, (2) the transformation of the products into
chiral propargylic and allylic alcohols, and (3) ab initio
calculation of the elimination reaction of (trimethylsilyl)-
and tert-butylvinyl sulfoxides.
Optically active propargylic alcohols are important
synthetic intermediates in the synthesis of natural
products.1 A number of asymmetric syntheses of prop-
argylic alcohols have been reported, e.g., asymmetric
reduction of ynones,1e,j,2 addition of metalated acetylenes
to aldehydes,3 and reaction of alkynylaldehydes with
nucleophiles.4 However, these previously reported asym-
metric syntheses appear to incur difficulty in the prepa-
ration of propargylic alcohols with high optical purity.
Recently, we reported that the reaction of R-sulfinyl
(1) (a) Stoddart, J . F. Comprehensive Organic Chemistry; Pergamon
Press: Oxford, 1979; Vol. 1, pp 193-208. (b) Zweifel, G.; Miller, J . A.;
Org. React. 1984, 32, 375-517. (c) Stang, P. J .; Diederich, F., Eds.
Modern Acetylene Chemistry; VCH: Weinheim, 1995. (d) Fried, J .; Sih,
J . C. Tetrahedron Lett. 1973, 40, 3899-3902. (e) J ohnson, W. S.;
Brinkmeyer, R. S.; Kapoor, V. M.; Yarnell, T. M. J . Am. Chem. Soc.
1977, 99, 8341-8343. (f) Cohen, N.; Lopresti, R. J .; Neukom, C.; Saucy,
G. J . Org. Chem. 1980, 45, 582-588. (g) Vigneron, J . P.; Dhaenens, R.
M. M. Tetrahedron Lett. 1980, 21, 2057-2060. (h) Overman, L. E.; Bell,
K. L. J . Am. Chem. Soc. 1981, 103, 1851-1853. (i) Stork, G.;
Nakamura, E. J . Am. Chem. Soc. 1983, 105, 5510-5512. (j) Senda, S.;
Mori, K. Agric. Biol. Chem. 1983, 47, 2595-2598. (k) Noyori, R.;
Tomino, I.; Yamada, M.; Nishizawa, M. J . Am. Chem. Soc. 1984, 106,
6717-6725. (l) Kluge, A. F.; Kertesz, D. J .; Yang, C.; Wu, H. Y. J . Org.
Chem. 1987, 52, 2860-2868. (m) Nicolau, K. C.; Dai, W. M. Angew.
Chem., Int., Ed. Engl. 1991, 30, 1387-1530.
(2) (a) Midland, M. M.; McDowell, D. C.; Hatch, R. L.; Tramontano,
A. J . Am. Chem. Soc. 1980, 102, 867-869. (b) Brown, H. C.; Chan-
drasekharan, J .; Ramachandran, P. V. J . Am. Chem. Soc. 1988, 110,
1539-1546. (c) Brown, H. C.; Ramachandran, P. V. Acc. Chem. Res.
1992, 25, 16-24. (d) Bach, J .; Berenguer, R.; Garcia, J .; Loscertales,
T.; Vilarrasa, J . J . Org. Chem. 1996, 61, 9021-9025. (e) Halal, C. J .;
Magriotiis, P. A.; Corey, E. J . J . Am. Chem. Soc. 1996, 118, 10938-
10939. (f) Matsumura, K.; Hashiguchi, S.; Ikariya, T.; Noyori, R. J .
Am. Chem. Soc. 1997, 119, 8738-8739. (g) Parker, K. A.; Ledeboer,
M. W. J . Org. Chem. 1996, 61, 3214-3217.
(3) (a) Mukaiyama, T.; Suzuki, K.; Soai, K.; Sato, T. Chem. Lett.
1979, 447-448. (b) Niwa, S.; Soai, K. J . Chem. Soc., Perkin Trans. 1
1990, 937-943. (c) Tombo, G. M. R.; Didier, E. Synlett 1990, 547-
548. (d) Corey. E. J .; Cimprich, K. A. J . Am. Chem. Soc. 1994, 116,
3151-3152. (e) Tan, L.; Chen, C.-Y.; Tillyer, R. D.; Grabowski, E. J .
J .; Reider, P. J . Angew. Chem., Int. Ed. Engl. 1999, 38, 711-713. (f)
Li, Z.; Upadhyay, V.; DeCamp, A. E.; DiMichele, L.; Reider, P. J .
Synthesis 1999, 1453-1458. (g) Frantz, D. E.; Fa¨ssler, R.; Carreira,
E. M. J . Am. Chem. Soc. 2000, 122, 1806-1807. (h) Frantz, D. E.;
Fa¨ssler, R.; Tomooka, C. S.; Carreira, E. M. Acc. Chem. Res. 2000, 33,
373-381. (i) Boyall, D.; Lopez, F.; Sasaki, H.; Frantz, D.; Carreira, E.
M. Org. Lett. 2000, 2, 4233-4236. (j) Sasaki, H.; Boyall, D.; Carreira,
E. M. Helv. Chim. Acta 2001, 84, 964-971.
Resu lts a n d Discu ssion
P r ep a r a tion of (R)-(E)-2-(Tr ia lk ylsilyl)vin yl Su l-
foxid es 3a -d . (R)-(E)-2-(Trialkylsilyl)vinyl sulfoxides
3a -d were easily synthesized from readily obtainable
(R)-p-tolyl 2-(trialkylsilyl)ethyl sulfoxides 1a -c or (R)-
tert-butyl 2-(trialkylsilyl)ethyl sulfoxide 1d 7 in two steps
as shown in Table 1. Treatment of a THF solution of
1a -d with 1.1 equiv of LDA at -78 °C for 1 h and
(4) (a) Soai, K.; Niwa, S. Chem. Lett. 1989, 481-484. (b) Kobayashi,
S.; Furuya, M.; Ohtsubo, A.; Mukaiyama, T. Tetrahedron: Asymmetry
1991, 2, 635-638. (c) Weber, B.; Seebach. D. Tetrahedron 1994, 50,
7473-7484. (d) Singer, R. A.; Shepard, M. S.; Carreira, E. M.
Tetrahedron 1998, 54, 7025-7032.
(5) (a) Kusuda, S.; Ueno, Y.; Toru, T. Tetrahedron 1994, 50, 1045-
1062. (b) Toru, T.; Nakamura, S.; Takemoto, H.; Ueno, Y. Synlett 1997,
449-450. (c) Nakamura, S.; Watanabe, Y.; Toru, T. J . Chem. Soc.,
Perkin Trans. 1 1999, 3403-3404. (d) Nakamura, S.; Takemoto, H.;
Ueno, Y.; Toru, T.; Kakumoto, T.; Hagiwara, T. J . Org. Chem. 2000,
65, 469-474. (e) Nakamura, S.; Watanabe, Y.; Toru, T. J . Org. Chem.
2000, 65, 1758-1766.
(6) Kusuda, S.; Kawamura, K.; Ueno, Y. Toru, T. Tetrahedron Lett.
1993, 34, 6587-6590.
(7) (R)-p-tolyl 2-(trialkylsilyl)ethyl sulfoxides 1a -c or (R)-tert-butyl
2-(trialkylsilyl)ethyl sulfoxide 1d could be readily synthesized, see refs
5a, d.
10.1021/jo0157223 CCC: $22.00 © 2002 American Chemical Society
Published on Web 01/04/2002

Elimination Reaction of Vinyl Sulfoxides
J . Org. Chem., Vol. 67, No. 3, 2002 641
Ta ble 1. P r ep a r a tion of (R)-(E)-2-(Tr ia lk ylsilyl)vin yl
Su lfoxid es 3a -d a n d 2a -d
Ta ble 2. Rea ction of Silylvin yl Su lfoxid es 3a -d w ith
Va r iou s Ald eh yd es
sulfoxide
yield
aldehyde R3 product (%) (S)-4:(R)-4
ratioa
entry
R1
SiR2
3
1
2
3
4
5
6
7
8
9
3a Tol SiMe3
3a Tol SiMe3
3a Tol SiMe3
3a Tol SiMe3
3a Tol SiMe3
3b Tol SiPh2Me
3c Tol SiPh3
3c Tol SiPh3
3d t-Bu SiMe3
3d t-Bu SiMe3
Ph
Me
n-C5H11
i-Pr
t-Bu
n-C5H11
n-C5H11
t-Bu
4a
4b
4c
4d
4e
4f
4g
4h
4i
88
82
93
92
71
77
70
74
88
82
70
65
45:55
68:32
73:27
68:32
76:24
69:31
66:34
67:33
34:66
29:71
37:63
32:68
yield
(%)
diastereomer
ratioa
yield
(%)
ee
(%)
product
product
2a
2b
2c
2d
60
89
53
69
82:18
79:21
77:23
85:15
3a
3b
3c
3d
94
92
80
97
>99b
>99b
>99b
>99c
Ph
10
n-C5H11
n-C5H11
n-C5H11
4j
4c
4f
a
b
Determined by the 1H NMR analysis. Determined by the
HPLC (Chiralcel OB-H) analysis. c Determined by the 1H NMR
analysis using (R)-(-)-(3,5-dinitrobenzoyl)-R-phenethylamine.
11b 3a Tol SiMe3
12b 3b Tol SiPh2Me
a
b
Isolated ratio. HMPA (2.0 equiv) was added.
subsequently with 1.2 equiv of phenylselenenyl bromide
gave R-(phenylseleno)ethyl sulfoxides 2a -d which were
selectively oxidized with m-CPBA in CH2Cl2 at 0 °C to
give enantiomerically pure 2-(trialkylsilyl)vinyl sulfoxides
3a -d . The geometry of the products 3a -d was deter-
mined to be E by the coupling constants (J ) 17.5-18.1
Hz) in their 1H NMR spectra. The optical purities of
3a -d were determined to be >99% ee by the HPLC
analysis using Chiralcel OB-H or by the 1H NMR
analysis in the presence of (R)-(-)-(3,5-dinitrobenzoyl)-
R-phenethylamine8 as a chiral shift reagent.
Rea ction of th e r-Vin yl An ion s Der ived fr om
Silylvin yl Su lfoxid es 3a -d w ith Ald eh yd es. We first
investigated the reaction of the R-vinyl anions derived
from 3a -d with various aldehydes. However, treatment
of 3a -d with 1.1 equiv of LDA in THF at -100 °C formed
a number of undesired products, which consisted of
oligomers probably formed from the partially lithiated
3a -d . To avoid this oligomerization, the sulfoxides 3a -d
were treated with 2.0 equiv of LDA in THF at -100 °C
for 20 min to generate the lithium carbanion completely,
which was then reacted with an aldehyde at the same
temperature for 5 min giving good yields of the products
4a -j. The yields and the diastereomer ratios obtained
in the reaction with benzaldehyde, acetaldehyde, hexa-
nal, isobutyraldehyde, and 2,2-dimethylpropionaldehyde
are shown in Table 2.
Desilylsu lfin yla tion , Desilyla tion , a n d Desu lfin yl-
a tion fr om (S)-4 a n d (R)-4. P r ep a r a tion of Op tica lly
P u r e P r op a r gylic Alcoh ols. The resulted diastereo-
mers (S)-4 and (R)-4 could be easily separated by silica
gel column chromatography, and they were separately
subjected to the following transformations. Treatment of
(S)-4a ,c and (R)-4 with tetrabutylammonium fluoride
(TBAF) in THF at room temperature afforded the desi-
lylated allylic alcohols (S)-6 and (R)-6, respectively, as
major products in moderate yields together with the
formation of the propargylic alcohols 5 as minor products
(Table 3). These results are in sharp contrast with those
obtained in a similar treatment of the products from the
â-silylethyl sulfoxides resulting in the simultaneous
elimination of the sulfinyl and the trimethylsilyl groups.
Interestingly, the addition of water was found to be
effective for the selective desilylation to obtain 6 probably
due to the rapid protonation of the vinyl anion formed
during the reaction.
Thus, reaction of (S)-4a and (R)-4a with TBAF in the
presence of water almost exclusively afforded (S)-6a and
(R)-6a , respectively (entries 5 and 6), although it took
longer to complete the reaction. To clarify the role of the
hydroxyl group for desilylation, reaction of the THP-
protected (R)-4a with TBAF was examined. It gave
propargylic alcohol (R)-5a in higher yield than that of
(R)-4a without protection (entry 7). In addition, desilyl-
ation of p-tolyl 2-(trimethylsilyl)vinyl sulfoxide 3a with
TBAF at 0 °C in THF for 3 h did not smoothly proceed
and gave the desilylated product 7 in low yield (Scheme
1).
The reaction of lithiated 3a -c with aldehydes gave the
products 4b-h with moderate selectivity (entries 2-8),
favoring the formation of the (S)-isomer except for the
reaction with benzaldehyde (entry 1). The stereoselective
outcome appears to be irrespective of the steric bulkiness
of the aldehydes and the silyl groups (entries 1-8). These
results are not in accord with the previously reported
results of the reaction of R-lithiated vinyl sulfoxides with
aldehydes, in which bulky aldehydes afford highly stereo-
selective adducts.9 Notably, replacement of the p-tolyl
group with the tert-butyl group reversed the stereoselec-
These results indicate that the hydroxyl group in 4
plays a significant role in effecting desilylation. Proto-
nation of the vinyl anion by the hydroxyl group would
suppress the subsequent desulfinylation and lead to the
tivity, favoring the (R)-isomer (entries 9 and 10).9d
A
(9) Reaction of R-lithiated vinyl sulfoxides with aldehydes give the
products generally with low diastereoselectivity, see (a) Posner, G. H.;
Mallamo, J . P.; Miura, K.; Hulce, M. Pure Appl. Chem. 1981, 53, 2307-
2314. (b) Solladie´, G.; Moine, G. J . Am. Chem. Soc. 1984, 106, 6097-
6098. (c) House, S.; J enkins, P., R.; Fawcett, J .; Russell, D. R. J . Chem.
Soc., Chem. Commun. 1987, 1844-1845. (d) Fawcett, J .; House, S.;
J enkins, P. R.; Lawrence, N. J .; Russell, D. R. J . Chem. Soc., Perkin
Trans. 1 1993, 67-73. (e) Bonfand, E.; Gosselin, P.; Maignan, C.
Tetrahedron: Asymmetry 1993, 4, 1667-1676.
similar stereoselectivity was obtained in the reaction of
p-tolyl sulfoxides 1a ,b in the presence of HMPA (2 equiv)
(entries 11 and 12).9d
(8) Deshmukh, M.; Dunach, E.; J uge, S.; Kagan, H. B. Tetrahedron
Lett. 1984, 25, 3467-3470.

642 J . Org. Chem., Vol. 67, No. 3, 2002
Nakamura et al.
Ta ble 3. Selective Con ver sion of 4 in to Allylic Alcoh ols 6 on Tr ea tm en t w ith Tetr a bu tyla m m on iu m F lu or id e
substrate,
R
reaction
temp
reaction
time
5 yield
(%)
6 yield
(%)
de
entry
additive
(%)a
1
2
3
4
5
6
7
(S)-4a
(R)-4a
(S)-4c
(R)-4a
Ph
Ph
n-C5H11
Ph
Ph
rt
rt
rt
0
0frt
0frt
rt
5 min
5 min
5 min
30 min
12 h
25
28
31
13
3
(S)-6a
(R)-6a
(S)-6c
(R)-6a
(S)-6a
(R)-6a
THP-(R)-6a
57
63
65
84
96
90
23
>99
>99
>99
>99
>99
>99
>99
(S)-4a
H2O (10 equiv)
H2O (10 equiv)
(R)-4a
Ph
Ph
12 h
5 min
8
THP-(R)-4a b
42c
a
b
Determined by 1H NMR and HPLC analyses of the corresponding MTPA ester. The THP-protected (R)-4a was used. c The THP-
protected product was obtained.
Sch em e 1
Sch em e 3
Sch em e 2
1
pure (>99% ee) by H NMR and HPLC analyses after
conversion to the corresponding MTPA esters.10
The predominant formation of the propargylic alcohols
5 can be ascribed to the â-elimination initiated by an
intramolecular attack of the alkoxide ion on the silicon
as shown in Scheme 3.
Ta ble 4. Tr ea tm en t of 4 w ith Na H in to P r op a r gylic
Alcoh ols 5 a n d Allylic Alcoh ols 6
On the other hand, thermal treatment of each dia-
stereomer of 4 readily induced the elimination of the
sulfenic acid, and the elimination was complete within 1
h under reflux in toluene to give the trimethylsilylpro-
pargylic alcohols 8 in excellent yields as shown in Table
5.
Transformation of the vinyl sulfoxides without any
accelerating groups into the acetylenic linkage is known
to be unsuccessful11,12 and only the more reactive vinyl
selenoxides can undergo elimination to give triple bonds,
although strong basic conditions are needed.13 Thus, the
present easy formation of 8 from the trimethylsilyl
sulfoxides 4 is noteworthy, apparently owing to the
R-carbanion or â-carbocation stabilizing effect of the silyl
group.14,15 The tert-butyl sulfoxide 4j again showed inap-
substrate
5 yield ee 6 yield
entry
R1
R3
producta
(%)
(%)b
(%)
1
2
3
4
5
(S)-4a Tol
(R)-4a Tol
(S)-4c Tol
(R)-4c Tol
Ph
Ph
(R)-5a
(S)-5a
83
79
65
64
36
>99
>99
>99
>99
>99
5
8
10
14
63
n-C5H11 (S)-5c
n-C5H11 (R)-5c
(R)-4j t-Bu n-C5H11 (R)-5c
a
The absolute configuration was determined by comparison of
the specific rotation with the reported value. Determined by 1H
b
NMR and HPLC analyses of the corresponding MTPA ester.
desilylated allylic alcohols 6. Indeed, deuteration occurred
stereospecifically at the E position (Scheme 2).
(10) (a) Dale, J . A.; Dull, D. L.; Mosher, H. S. J . Org. Chem. 1969,
34, 2543-2549. (b) Dale, J . A.; Mosher, S. H. J . Am. Chem. Soc. 1973,
95, 512-519. (c) Trost, B. M.; Belletire, J . L.; Godleski, S.; McDougal,
P. G.; Balkovec, J . M.; Baldwin, J . J .; Christy, M. E.; Ponticello, G. S.;
Varga, S. L.; Springer, J . P. J . Org. Chem. 1986, 51, 2370-2374.
(11) Thermal desilylsulfinylation of the (Z)-â-silyl-R-sulfinyl-R,â-
unsaturated ketone has been reported to give the acetylenic ketone,
whereas thermal treatment of (E)-isomer hardly induces the elimina-
tion, see Fleming, I.; Goldhill, J .; Perry, D. A. J . Chem. Soc., Perkin
Trans. 1 1982, 1563-1569.
(12) We confirmed thermal treatment of a toluene solution of
nonsilylated sulfoxide 6 under reflux gave no acetylenic compound.
(13) Reich, H.-J .; Willis, W. W. J . Am. Chem. Soc. 1980, 102, 5967-
5968.
(14) The effect of the silyl group on the thermal elimination of the
sulfinyl group to a double bond has been reported, see Ochiai, M.; Tada,
S.; Sumi, K.; Fujita, E. J . Chem. Soc., Chem. Commun. 1982, 281-
282, and see also refs 5 and 10.
On the other hand, optically pure propargylic alcohols
could be selectively prepared as shown in Table 4. The
(S)- and (R)-isomers of 4a ,c were separately treated with
sodium hydride (1.2 equiv) in THF at 0 °C for 1 h to give
the optically active propargylic alcohols 5a ,c in good
yields accompanied with a small amount of the desily-
lated allylic alcohols 6 (entries 1-4). A similar treatment
of the tert-butyl vinyl sulfoxide 4j predominantly gave
the allylic alcohol 6j, showing the tert-butyl sulfoxide is
not an appropriate substrate for the preparation of the
propargylic alcohols (entry 5). The obtained propargylic
alcohols 5a ,c were determined to be enantiomerically

Elimination Reaction of Vinyl Sulfoxides
J . Org. Chem., Vol. 67, No. 3, 2002 643
Ta ble 5. Th er m a l Tr ea tm en t of 4 in to
Tr im eth ylsilylp r op a r gylic Alcoh ols 8
yield
(%)
ee
entry
R1
R3
producta
(%)b
1
2
3
4
5
6
7
(S)-4a
(R)-4a
(S)-4b
(R)-4b
(S)-4c
(R)-4c
(R)-4j
Tol
Tol
Tol
Tol
Tol
Tol
t-Bu
Ph
Ph
Me
(S)-8a
(R)-8a
(S)-8b
(R)-8b
(S)-8c
(R)-8c
(R)-8d
87
95
71
71
80
66
23
>99
>99
>99
>99
>99
>99
>99
Me
F igu r e 1. relative energies of the optimized structures of 9
and 10.
n-C5H11
n-C5H11
n-C5H11
the sulfenic acid. The intrinsic reaction coordination
(IRC) calculation starting from TS-9 and TS-10 con-
firmed the formation of the starting sulfoxides 9 and 10
and the products, the alkyne and the sulfenic acid. Figure
2 shows the relative energies of the optimized transition
states TS-9 and TS-10 to those of the respective opti-
mized ground states 9 and 10.
The structure of the transition state TS-10 was also
similar to TS-9, and the activation energy from 10 (34.7
kcal/mol) was apparently lower than that from 9 (53.6
kcal/mol). We also calculated stabilizing effects of the
silicon in transition states using the NPA19 and the NBO
analyses.20 These analyses showed that the stabilizing
effect of the silicon on the cationic Câ-carbon was larger
in comparison with that on the anionic CR-carbon.21,22
Thus, the acceleration of the sulfenic acid-elimination
reaction from the â-silylvinyl sulfoxide 10 can be ascribed
mainly to the stabilizing effect of the silicon on the
cationic Câ-carbon.
a
The absolute configuration was determined by comparison of
the specific rotation with the reported value. Determined by 1H
NMR and HPLC analyses of the corresponding MTPA ester.
b
propriate reactivity for the preparation of the silyl
propargylic alcohols, giving 8d in low yield probably due
to the desulfinylation occurring toward the tert-butyl
group.16
To gain more quantitative information on the effect of
the silyl group in the elimination reaction, the activation
energies of the elimination reaction from 2-(tert-butyl)-
vinyl sulfoxide 9 and 2-(trimethylsilyl)vinyl sulfoxide 10
were estimated by ab initio calculation. First, the relative
stabilities of conformers of 9 and 10 were calculated with
Gaussian 9817 HF/3-21+G*. These optimized structures
were confirmed to have no negative frequency by the
frequency calculations. The thermal correction from 0 to
384 K, including the correction of zero-point energies, was
obtained from HF/3-21+G* calculations of vibrational
frequencies scaled by 0.9409. The relative energies of the
optimized structures of 9 and 10 obtained by these
calculations are depicted in Figure 1.
Su m m a r y
The optimized conformers 9 and 10 were structurally
similar, and their dihedral angles (O-S-Câ-CR) were
127.2° and 132.7°, respectively. Next, we calculated the
transition states for the elimination reaction from the
sulfoxides 9 and 10. It is well-known that the thermal
elimination reaction of the sulfenic acid from the sulfox-
ide proceeds through a five-membered cyclic transition
state.11,13,18 The five-membered cyclic transition struc-
tures were fully optimized without any constraint and
characterized by vibrational-frequency calculations, lead-
ing to the transition states TS-9 and TS-10 with a
negative frequency corresponding to the elimination of
The reaction of the vinyl anion R to the chiral sulfinyl
group with aldehydes, separation of diastereomers, and
specific elimination reactions provide reliable routes for
the selective synthesis of optically pure propargylic
alcohols, trimethylsilylpropargylic alcohols, and sulfinyl-
substituted allylic alcohols. The MO calculations revealed
that acceleration of the sulfenic acid-elimination from the
â-(trimethylsilyl)vinyl sulfoxide could be ascribed mainly
to the â-effect of the silyl group.
Exp er im en ta l Section
Rep r esen ta tive P r oced u r e for th e P r ep a r a tion of th e
r-Selen osu lfoxid e. 1-P h en ylselen o-1-[(S)-p-tolylsu lfin yl]-
2-(tr im eth ylsilyl)eth a n e (2a ). To a solution of diisopropyl-
amine (0.028 mL, 0.21 mmol) in THF (0.28 mL) was added
n-butyllithium (1.57 mol dm-3 in hexane, 0.135 mL, 0.21 mmol)
(15) For reviews of the â-effect of the silyl group, see (a) Lambert,
J . B. Tetrahedron 1990, 46, 2677-2689. (b) Apeloig, Y. In The
Chemistry of Organic Silicon compounds; Patai, S.; Rappoport, Z., Eds.;
Wily-Interscience: New York, 1989; pp 57-225.
(16) Emerson, D. W.; Craig, A. P.; Potts, J r., I. W. J . Org. Chem.
1967, 32, 102-105.
(17) Frisch, M. J .; Trucks, G. W.; Schlegel, H. B.; Scuseria, G. E.;
Robb, M. A.; Cheeseman, J . R.; Zakrzewski, V. G.; Montgomery, J r.,
J . A.; Stratmann, R. E.; Burant, J . C.; Dapprich, S.; Millam, J . M.;
Daniels, A. D.; Kudin, K. N.; Strain, M. C.; Farkas, O.; Tomasi, J .;
Barone, V.; Cossi, M.; Cammi, R.; Mennucci, B.; Pomelli, C.; Adamo,
C.; Clifford, S.; Ochterski, J .; Petersson, G. A.; Ayala, P. Y.; Cui, Q.;
Morokuma, K.; Malick, D. K.; Rabuck, A. D.; Raghavachari, K.;
Foresman, J . B.; Cioslowski, J .; Ortiz, J . V.; Stefanov, B. B.; Liu, G.;
Liashenko, A.; Piskorz, P.; Komaromi, I.; Gomperts, R.; Martin, R. L.;
Fox, D. J .; Keith, T.; Al-Laham, M. A.; Peng, C. Y.; Nanayakkara, A.;
Gonzalez, C.; Challacombe, M.; Gill, P. M. W.; J ohnson, B.; Chen, W.;
Wong, M. W.; Andres, J . L.; Gonzalez, C.; Head-Gordon, M.; Replogle,
E. S.; Pople, J . A. Gaussian 98, Revision A.6, Gaussian, Inc., Pitts-
burgh, PA, 1998.
(18) (a) Kingsbury, C. A.; Cram, D. J . J . Am. Chem. Soc. 1960, 82,
1810-1819. (b) Kwart, H.; George, T. J .; Louw, R.; Ultee, W. J . Am.
Chem. Soc. 1978, 100, 3927-3930. (c) Yoshimura, T.; Yoshizawa, M.;
Tsukurimichi, E. Bull. Chem. Soc. J pn. 1987, 60, 2491-2496. (d)
Yoshimura, T.; Tsukurimichi, E.; Iizawa, Y.; Mizuno, H.; Isaji, H.;
Shimasaki, C. Bull. Chem. Soc. J pn. 1989, 62, 1891-1899.
(19) (a) Reed, A. E.; Weinhold, F. J . Chem. Phys. 1983, 78, 4066-
4073. (b) Reed, A. E.; Weinstock, R. B.; Weinhold, F. J . Chem. Phys.
1985, 83, 735-746.
(20) NBO Ver. 3.1: Glendening, E. D.; Reed, A. E.; Carpenter, J .
E.; Weinhold, F. See also ref 18b.
(21) See Supporting Information.
(22) A similar calculation result was obtained in the elimination
reaction from â-(trimethylsilyl)ethyl sulfoxide.

644 J . Org. Chem., Vol. 67, No. 3, 2002
Nakamura et al.
F igu r e 2. optimized transition states TS-9 and TS-10 and their relative energies to the corresponding ground states.
at 0 °C, and the mixture was stirred for 30 min. The reaction
mixture was cooled to -78 °C, and then a solution of 1a (42
mg, 0.17 mmol) in THF (0.25 mL) was added dropwise over a
period of 10 min. The mixture was stirred for an additional 1
h. Phenylselenenyl bromide (0.050 mg, 0.21 mmol) in THF
(0.25 mL) was then added, and the mixture was stirred for 4
h, the solution was quenched with saturated aqueous NH4Cl
(5 mL) under vigorous stirring, and the organic layer was
separated. The aqueous layer was extracted with CH2Cl2 and
the combined organic extracts were washed with brine, dried
over MgSO4, filtered, and concentrated under reduced pressure
to give the crude product which was purified by column
chromatography (silica gel 9 g, hexane/ethyl acetate ) 85:15)
to give 2a (41 mg, 60%). The diastereomer ratio was deter-
mined to be 82:18 by the 1H NMR analysis of the crude
1260, 1200, 1120, 1040, 810, 740, 710 cm-1; EIMS m/z (rel
intensity) 583 (M+, 3), 424 (3), 398 (58), 259 (100). Found: C,
68.21; H, 5.38. Calcd for C33H30OSSeSi: C, 68.14; H, 5.20%.
1-[(S)-ter t-Bu tylsu lfin yl]-1-p h en ylselen o-2-(tr im eth yl-
silyl)eth a n e (2d ). The reaction was carried out as described
above except using 1d (896 mg, 4.34 mmol). Usual workup
gave the crude product which was purified by column chro-
matography (silica gel, hexane/ethyl acetate ) 80:20) to afford
2d (1.08 g, 69%). The diastereomer ratio was determined to
be 85:15 by the 1H NMR analysis of the crude product.
Recrystallization from hexanes-ethyl acetate afforded dia-
stereomerically pure 2d ; δ 0.18 (s, 9H), 0.87 (dd, 1H, J ) 13.1,
16.0 Hz), 1.08 (s, 9H), 1.48 (dd, 1H, J ) 2.2, 16.0 Hz), 4.00
(dd, 1H, J ) 2.2, 13.1 Hz), 7.28-7.70 (m, 5H); IR (neat) 2950,
1460, 1430, 1400, 1360, 1250, 1170, 1030, 840, 740, 690 cm-1
;
1
EIMS m/z (rel intensity) 255 (M+-C4H9OS, 2), 105 (12), 73
(100). Found: C, 49.93; H, 7.47. Calcd for C15H16OSSeSi: C,
49.84; H, 7.25%.
product. H NMR (for major) δ 0.07 (s, 9H), 0.31 (dd, 1H, J )
12.7, 15.0 Hz), 1.72 (dd, 1H, J ) 2.8, 15.0 Hz), 2.41 (s, 3H),
3.67 (dd, 1H, J ) 2.8, 12.7 Hz), 7.10-7.70 (m, 9H); (for minor)
δ 0.04 (s, 9H), 0.95 (dd, 1H, J ) 13.0, 15.0 Hz), 1.50 (dd, 1H,
J ) 2.6, 15.0 Hz), 2.41 (s, 3H), 3.67 (dd, 1H, J ) 2.6, 13.0 Hz),
7.10-7.70 (m, 9H); IR (neat) 3050, 2950, 1570, 1470, 1430,
1240, 1030, 840, 780 cm-1; EIMS m/z (rel intensity) 256 (M+-
C7H8OS, 55), 241 (10), 140 (60), 91 (100). Found: C, 54.79; H,
6.39. Calcd for C18H24OSSeSi: C, 54.67; H, 6.12%.
Rep r esen ta tive P r oced u r e for th e P r ep a r a tion of th e
Vin ylsu lfoxid e. (E)-1-[(R)-p-Tolylsu lfin yl]-2-(tr im eth yl-
silyl)eth ylen e (3a ). To a solution of 2a (52 mg, 0.13 mmol)
in CH2Cl2 (1.0 mL) was added m-CPBA (29.4 mg, 0.14 mmol)
in CH2Cl2 (0.5 mL) at -78 °C, and the mixture was stirred for
1 h. The solution was quenched with 10% aqueous Na2SO3 (4
mL). The aqueous layer was extracted with CH2Cl2 and the
combined organic extracts were washed with brine, dried over
MgSO4, filtered, and concentrated under reduced pressure to
give the crude product which was purified by column chroma-
tography (silica gel 7 g, hexane/ethyl acetate ) 90:10) to give
3a (29 mg, 94%). E/Z ratio was determined to be >98:2 by the
2-(Meth yld ip h en ylsilyl)-1-p h en ylselen o-1-[(S)-p-tolyl-
su lfin yl]eth a n e (2b). The reaction was carried out as de-
scribed above except using 1b (184 mg, 0.50 mmol). Usual
workup gave the crude product which was purified by column
chromatography (silica gel, hexane/ethyl acetate ) 80:20) to
afford 2b (234 mg, 89%). The diastereomer ratio was deter-
mined to be 79:21 by the 1H NMR analysis of the crude
1H NMR analysis of the crude product. [R]26 +344.0 (c 0.29
D
1
1
product. H NMR (for major) δ 0.66 (s, 3H), 0.86 (dd, 1H, J )
in EtOH); H NMR δ 0.12 (s, 9H), 2.39 (s, 3H), 6.58 (d, 1H,
12.3, 15.2 Hz), 2.28 (dd, 1H, J ) 3.2, 15.2 Hz), 2.36 (s, 3H),
4.06 (dd, 1H, J ) 3.2, 12.3 Hz), 7.03-7.59 (m, 19H); (for minor)
δ 0.66 (s, 3H), 1.41 (dd, 1H, J ) 12.3, 15.2 Hz), 1.50 (dd, 1H,
J ) 3.0, 15.2 Hz), 2.30 (s, 3H), 3.75 (dd, 1H, J ) 3.0, 12.3 Hz),
7.03-7.59 (m, 19H); IR (neat) 3050, 1580, 1480, 1430, 1260,
1190, 1120, 1050, 820, 740, 700 cm-1; EIMS m/z (rel intensity)
520 (M+, 1), 380 (90), 197 (100). Found: C, 64.86; H, 5.70.
Calcd for C28H28OSSeSi: C, 64.72; H, 5.43%.
1-P h en ylselen o-1-[(S)-p-tolylsu lfin yl]-2-(tr iph en ylsilyl)-
eth a n e (2c). The reaction was carried out as described above
except using 1c (1.02 g, 2.39 mmol). Usual workup gave the
crude product which was purified by column chromatography
(silica gel, hexane/ethyl acetate ) 99:1) to afford 2c (740 mg,
53%). The diastereomer ratio was determined to be 77:23 by
the 1H NMR analysis of the crude product. 1H NMR (for major)
δ 1.24 (dd, 1H, J ) 11.5, 15.5 Hz), 2.36 (s, 3H), 2.60 (dd, 1H,
J ) 3.7, 15.5 Hz), 3.85 (dd, 1H, J ) 3.7, 11.5 Hz), 6.95-7.55
(m, 24H); (for minor) δ 1.76 (dd, 1H, J ) 12.7, 15.7 Hz), 2.28
(dd, 1H, J ) 2.4, 15.7 Hz), 2.36 (s, 3H), 3.85 (dd, 1H, J ) 2.4,
12.7 Hz), 6.95-7.55 (m, 24H); IR (neat) 3050, 1580, 1490, 1440,
17.5 Hz), 6.94 (d, 1H, J ) 17.5 Hz), 7.29 (d, 2H, J ) 7.9 Hz),
7.46 (d, 2H, J ) 7.9 Hz); IR (neat) 2950, 1570, 1240, 1140,
1080, 1040, 970, 860, 830, 720 cm-1; EIMS m/z (rel intensity)
238 (M+, 5), 212 (90), 140 (80), 73 (100). Found: C, 60.39; H,
7.67. Calcd for C12H18OSSi: C, 60.45; H, 7.61%. HPLC (Daicel
Chiralcel OB-H, hexane/i-PrOH ) 95:5, flow rate 0.50 mL/
min) tR 22.4 (R) min (>99% ee).
(E)-2-(Dip h en ylm eth ylsilyl)-1-[(R)-p-tolylsu lfin yl]eth -
ylen e (3b). The reaction was carried out as described above
except using 2b (711 mg, 1.37 mmol). Usual workup gave the
crude product which was purified by column chromatography
(silica gel, hexane/ethyl acetate ) 80:20) to afford 3b (455 mg,
92%). E/Z ratio was determined to be >98:2 by the 1H NMR
analysis of the crude product. mp 96-97 °C; [R]20 +263.4 (c
D
0.34 in acetone); 1H NMR δ 0.68 (s, 3H), 2.41 (s, 3H), 6.70 (d,
1H, 17.7 Hz), 7.27-7.51 (m, 15H); IR (KBr) 2950, 1570, 1420,
1250, 1110, 1080, 1040, 970, 810, 790, 765, 730, 700 cm-1
;
EIMS m/z (rel intensity) 223 (M+-C7H7OS, 66), 197 (100), 165
(18). Found: C, 72.67; H, 5.85. Calcd for C22H22OSSi: C, 72.88;
H, 6.12%.

Elimination Reaction of Vinyl Sulfoxides
J . Org. Chem., Vol. 67, No. 3, 2002 645
(E)-1-[(R)-p-Tolylsu lfin yl]-2-(tr iph en ylsilyl)eth ylen e (3c).
The reaction was carried out as described above except using
2c (435 mg, 0.87 mmol). Usual workup gave the crude product
which was purified by column chromatography (silica gel,
hexane/ethyl acetate ) 99:1) to afford 3c (288 mg, 80%). E/Z
3H), 4.79 (dq, 1H, J ) 4.2, 6.7 Hz), 6.74 (s, 1H), 7.24 (d, 2H, J
) 8.3 Hz), 7.52 (d, 2H, J ) 8.3 Hz); IR (neat) 3300, 2950, 1600,
1500, 1400, 1360, 1250, 1110, 1030, 950, 910, 850, 810, 730
cm-1; EIMS m/z (rel intensity) 282 (M+, 3), 140 (90), 73 (100).
Found: C, 59.41; H, 7.95. Calcd for C14H22O2SSi: C, 59.53; H,
7.85%.
1
ratio was determined to be >98:2 by the H NMR analysis of
the crude product. mp 140-142 °C; [R]25 +179.6 (c 0.48 in
D
(SS,S)- a n d (SS,R)-(E)-2-(p-Tolylsu lfin yl)-1-(tr im eth yl-
silyl)-1-octen -3-ol (4c). The reaction was carried out as
described above except using 3a (40 mg, 0.17 mmol) and
hexanal (0.020 mL, 0.34 mmol). Usual workup gave the crude
product which was purified by column chromatography (silica
gel, hexane/ethyl acetate ) 80:20) to afford (SS,S)-4c (27 mg,
EtOH); 1H NMR δ 2.41 (s, 3H), 6.74 (d, 1H, J ) 17.5 Hz), 7.25-
7.58 (m, 20H); IR (KBr) 3050, 1580, 1490, 1430, 1260, 1140,
1120, 1060, 970, 810, 780, 740, 710 cm-1; EIMS m/z (rel
intensity) 424 (M+, 2), 398 (62), 284 (58), 259 (100), 207 (68),
140 (18). Found: C, 76.31; H, 5.76. Calcd for C27H24OSSi: C,
76.37; H, 5.70%.
68%) and (SS,R)-4c (12 mg, 25%). (SS,S)-4c: [R]20 +100.7 (c
D
(E)-1-[(R)-ter t-Bu t ylsu lfin yl]-2-(t r im et h ylsilyl)et h yl-
en e (3d ). The reaction was carried out as described above
except using 2d (62 mg, 0.17 mmol). Usual workup gave the
crude product which was purified by column chromatography
(silica gel, hexane/ethyl acetate ) 75:25) to afford 3d (33 mg,
96%). E/Z ratio was determined to be >98:2 by the 1H NMR
1
0.15 in acetone); H NMR δ 0.19 (s, 9H), 0.82 (t, 3H, J ) 6.5
Hz), 1.05-1.50 (m, 8H), 1.62 (br, 1H), 2.38 (s, 3H), 4.43 (br,
1H), 6.52 (s, 1H), 7.26 (d, 2H, J ) 8.0 Hz), 7.51 (d, 2H, J ) 8.0
Hz); IR (neat) 3350, 2920, 2850, 1590, 1490, 1450, 1240, 1080,
1030, 840, 800, 780, 760, 690 cm-1; EIMS m/z (rel intensity)
212 (M+-C8H14O, 9), 139 (45), 127 (100). Anal. Calcd for
analysis of the crude product. [R]26 +344.0 (c 0.29 in EtOH);
D
C
18H30O2SSi: C, 63.85; H, 8.93. Found: C, 63.63; H, 9.14.
1H NMR δ 0.14 (s, 9H), 1.20 (s, 9H), 6.60 (d, 1H, J ) 18.0 Hz),
6.87 (d, 1H, J ) 18.0 Hz); IR (neat) 2950, 1260, 1170, 1030,
980, 860, 840 cm-1; EIMS m/z (rel intensity) 204 (M+, 20), 189
(10), 105 (34), 73 (100). Found: C, 52.69; H, 9.72. Calcd for
C9H20OSSi: C, 52.89; H, 9.86%.
(SS,R)-4c: [R]20 +78.5 (c 0.21 in acetone); δ 0.21 (s, 9H), 0.84
D
(t, 3H, J ) 6.5 Hz), 1.05-1.60 (m, 8H), 1.75 (d, 1H, J ) 4.9
Hz), 2.38 (s, 3H), 4.58 (dt, 1H, J ) 4.9, 8.6 Hz), 6.77 (s, 1H),
7.25 (d, 2H, J ) 8.0 Hz), 7.52 (d, 2H, J ) 8.0 Hz); IR (neat)
3350, 2920, 2850, 1590, 1490, 1450, 1240, 1080, 1030, 840, 800,
780, 760, 690 cm-1; EIMS m/z (rel intensity) 212 (M+-C8H14O,
9), 139 (45), 127 (100). Found: C, 63.92; H, 8.72. Calcd for
Rep r esen ta tive P r oced u r e for th e Rea ction of Vin yl-
su lfoxid e w ith Ald eh yd e. (SS,S)- a n d (SS,R)-(E)-1-P h en yl-
2-(p-tolylsu lfin yl)-3-(tr im eth ylsilyl)-2-p r op en -1-ol (4a ). To
a solution of diisopropylamine (0.069 mL, 0.49 mmol) in THF
(0.50 mL) was added n-butyllithium (1.57 mol dm-3 in hexane,
0.31 mL, 0.49 mmol) at 0 °C, and the mixture was stirred for
30 min. The reaction mixture was cooled to -100 °C, and then
a solution of 3a (58.5 mg, 0.25 mmol) in THF (0.5 mL) was
added dropwise over a period of 10 min. The mixture was
stirred for an additional 10 min. Benzaldehyde (0.050 mL, 0.49
mmol) was then added, and the mixture was stirred for 20
min; the solution was quenched with saturated aqueous NH4-
Cl (3 mL) under vigorous stirring, and the organic layer was
separated. The aqueous layer was extracted with CH2Cl2, and
the combined organic extracts were washed with brine, dried
over MgSO4, filtered, and concentrated under reduced pressure
to give the crude product which was purified by column
chromatography (silica gel 10 g, hexane/ethyl acetate ) 95:5)
to give (SS,S)-4a (33 mg, 40%) and (SS,R)-4a (41 mg, 48%).
(SS,S)-4a : mp 124-125 °C; [R]27D +158.8 (c 0.37 in EtOH); 1H
NMR δ 0.15 (s, 9H), 2.35 (s, 3H), 2.93 (d, 1H, J ) 5.2 Hz),
5.49 (d, 1H, J ) 5.2 Hz), 6.70 (s, 1H), 7.10-7.38 (m, 9H); IR
(KBr) 3300, 2950, 1600, 1490, 1440, 1390, 1320, 1250, 1180,
1080, 1030, 1000, 840, 800, 730, 690 cm-1; EIMS m/z (rel
intensity) 344 (M+, 10), 204 (44), 189 (9), 140 (43), 73 (100).
Found: C, 66.11; H, 7.14. Calcd for C19H24O2SSi: C, 66.23; H,
C
18H30O2SSi: C, 63.85; H, 8.93%.
(SS,S)- a n d (SS,R)-(E)-4-Meth yl-2-(p-tolylsu lfin yl)-1-(tr i-
m eth ylsilyl)-1-p en ten -3-ol (4d ). The reaction was carried
out as described above except using 3a (61 mg, 0.27 mmol)
and isobutyraldehyde (0.047 mL, 0.52 mmol). Usual workup
gave the crude product which was purified by column chro-
matography (silica gel, CH2Cl2/ethyl acetate ) 99:1) to afford
(SS,S)-4d (50 mg, 47%) and (SS,R)-4d (24 mg, 21%). (SS,S)-
4d : mp 122-123 °C; [R]24D +237.0 (c 0.29 in acetone); 1H NMR
δ 0.21 (s, 9H), 0.82 (d, 3H, J ) 6.7 Hz), 0.97 (d, 3H, J ) 6.7
Hz), 1.89-2.60 (m, 1H), 2.32 (d, 1H, J ) 6.0 Hz), 2.40 (s, 3H),
3.89 (dd, 1H, J ) 6.0, 7.2 Hz), 6.51 (s, 1H), 7.28 (d, 2H, J )
8.0 Hz), 7.53 (d, 2H, J ) 8.0 Hz); IR (KBr) 3250, 2950, 1590,
1460, 1380, 1240, 1170, 1120, 1060, 1010, 1000, 920, 820, 810,
760, 740 cm-1; EIMS m/z (rel intensity) 310 (M+, 0.3), 212 (20),
140 (75), 73 (100). Found: C, 61.88; H, 8.42. Calcd for C16H26O2-
SSi: C, 61.89; H, 8.44%. (SS,R)-4d : mp 116-117 °C; [R]24
D
+131.0 (c 0.28 in acetone); 1H NMR δ 0.21 (s, 9H), 0.79 (d,
3H, J ) 6.8 Hz), 1.00 (d, 3H, J ) 6.0 Hz), 1.50 (d, 1H, J ) 6.0
Hz), 1.93-2.13 (m, 1H), 2.37 (s, 3H), 4.26 (dd, 1H, J ) 6.0, 8.3
Hz), 6.88 (s, 1H), 7.25 (d, 2H, J ) 8.0 Hz), 7.53 (d, 2H, J ) 8.0
Hz); IR (KBr) 3250, 2950, 1590, 1460, 1380, 1240, 1170, 1120,
1060, 1010, 1000, 920, 820, 810, 760, 740 cm-1; EIMS m/z (rel
intensity) 310 (M+, 1), 212 (20), 140 (75), 73 (100). Found: C,
61.88; H, 8.44. Calcd for C16H26O2SSi: C, 61.89; H, 8.44%.
7.02%. (SS,R)-4a : mp 117-118 °C; [R]28 +192.8 (c 0.50 in
D
1
EtOH); H NMR δ 0.20 (s, 9H), 2.34 (s, 3H), 2.42 (d, 1H, J )
(SS,S)- a n d (SS,R)-(E)-4,4-Dim eth yl-2-(p-tolylsu lfin yl)-
1-(tr im eth ylsilyl)-1-p en ten -3-ol (4e). The reaction was car-
ried out as described above except using 3a (39 mg, 0.16 mmol)
and 2,2-dimethylpropionaldehyde (0.035 mL, 0.32 mmol).
Usual workup gave the crude product which was purified by
column chromatography (silica gel, CH2Cl2/ethyl acetate ) 98:
2) to afford (SS,S)-4e (27 mg, 54%) and (SS,R)-4e (8 mg, 17%).
5.9 Hz), 5.82 (d, 1H, J ) 5.9 Hz), 6.98 (s, 1H), 7.10-7.38 (m,
9H); IR (KBr) 3300, 3050, 2950, 1600, 1490, 1440, 1390, 1320,
1250, 1180, 1080, 1030, 1000, 840, 800, 780, 730, 690 cm-1
;
EIMS m/z (rel intensity) 344 (M+, 6), 204 (45), 140 (28), 73
(100). Found: C, 66.24; H, 7.13. Calcd for C19H24O2SSi: C,
66.23; H, 7.02%.
(SS,S)- a n d (SS,R)-(E)-3-(p-Tolylsu lfin yl)-4-(tr im eth yl-
silyl)-3-bu ten -2-ol (4b). The reaction was carried out as
described above except using 3a (60 mg, 0.25 mmol) and
acetaldehyde (0.06 mL, 0.50 mmol). Usual workup gave the
crude product which was purified by column chromatography
(silica gel, hexane/ethyl acetate ) 87:13) to afford (SS,S)-4b
(SS,S)-4e: mp 124-125 °C; [R]21 +205.7 (c 0.40 in acetone);
D
1H NMR δ 0.19 (s, 9H), 1.02 (s, 9H), 2.39 (s, 3H), 2.52 (br,
1H), 3.86 (br, 1H), 6.53 (s, 1H), 7.27 (d, 2H, J ) 8.3 Hz), 7.50
(d, 2H, J ) 8.3 Hz); IR (KBr) 3200, 2950, 1590, 1460, 1380,
1360, 1290, 1245, 1180, 1060, 990, 890, 850, 810, 760 cm-1
;
EIMS m/z (rel intensity) 324 (M+, 0.5), 309 (0.4), 139 (95), 73
(100). Found: C, 63.07; H, 8.85. Calcd for C17H28O2SSi: C,
62.91; H, 8.70%. (SS,R)-4e: mp 95-96 °C; [R]24D +190.9 (c 0.15
(58 mg, 57%) and (SS,R)-4b (21 mg, 25%). (SS,S)-4b: [R]27
D
+195.9 (c 0.24 in acetone); 1H NMR δ 0.20 (s, 9H), 1.06 (d,
3H, J ) 6.6 Hz), 2.38 (s, 3H), 2.71 (d, 1H, J ) 4.4 Hz), 4.64-
4.70 (m, 1H), 6.54 (s, 1H), 7.25 (d, 2H, J ) 7.9 Hz), 7.52 (d,
2H, J ) 7.9 Hz); IR (neat) 3300, 2950, 1600, 1500, 1400, 1360,
1250, 1110, 950, 910, 850, 810, 730 cm-1; EIMS m/z (rel
intensity) 282 (M+, 3), 140 (95), 73 (100). Anal. Calcd for
1
in acetone); H NMR δ 0.23 (s, 9H), 0.93 (d, 1H, J ) 3.8 Hz),
1.05 (s, 9H), 2.37 (s, 3H), 4.50 (d, 1H, J ) 3.6 Hz), 7.10 (s,
1H), 7.24 (d, 2H, J ) 8.0 Hz), 7.54 (d, 2H, J ) 8.0 Hz); IR
(KBr) 3200, 2900, 1590, 1460, 1380, 1360, 1290, 1245, 1180,
1060, 990, 890, 850, 810, 760 cm-1; EIMS m/z (rel intensity)
324 (M+, 1), 309 (0.5), 139 (95), 73 (100). Found: C, 63.15; H,
8.94. Calcd for C17H28O2SSi: C, 62.91; H, 8.70%.
C
14H22O2SSi: C, 59.53; H, 7.85. Found: C, 59.41; H, 7.95.
1
(SS,R)-4b: [R]20 +76.0 (c 0.50 in EtOH); H NMR δ 0.22 (s,
D
9H), 1.34 (d, 3H, J ) 6.7 Hz), 1.91 (d, 1H, J ) 4.2 Hz), 2.37 (s,

646 J . Org. Chem., Vol. 67, No. 3, 2002
Nakamura et al.
(SS,S)- a n d (SS,R)-(E)-1-(Met h yld ip h en ylsilyl)-2-(p -
tolylsu lfin yl)-1-octen -3-ol (4f). The reaction was carried out
as described above except using 3b (22 mg, 0.06 mmol) and
hexanal (0.015 mL, 0.12 mmol). Usual workup gave the crude
product which was purified by column chromatography (silica
gel, CH2Cl2/ethyl acetate ) 99:1) to afford (SS,S)-4f (15 mg,
53%) and (SS,R)-4f (7 mg, 24%). (SS,S)-4f: mp 112-113 °C;
[R]18D +152.1 (c 0.15 in acetone); 1H NMR δ 0.70 (s, 3H), 0.72-
1.35 (m, 11H), 1.90 (d, 1H, J ) 5.5 Hz), 2.34 (s, 3H), 4.10 (dt,
1H, J ) 5.5, 6.8 Hz), 6.98 (s, 1H), 7.20-7.54 (m, 14H); IR (KBr)
(rel intensity) 310 (M+, 4), 178 (18), 105 (95), 73 (100). Found:
C, 61.62; H, 8.51. Calcd for C16H26O2SSi: C, 61.89; H, 8.44%.
(SS,S)- a n d (SS,R)-(E)-2-(ter t-Bu tylsu lfin yl)-1-tr im eth -
ylsilyl-1-octen -3-ol (4j). The reaction was carried out as
described above except using 3d (116 mg, 0.57 mmol) and
hexanal (0.137 mL, 1.14 mmol). Usual workup gave the crude
product which was purified by column chromatography (silica
gel, hexane/ethyl acetate ) 95:5) to afford (SS,S)-4j (41 mg,
24%) and (SS,R)-4j (101 mg, 58%). (SS,S)-4j: [R]20 -10.6 (c
D
1
0.10 in acetone); H NMR δ 0.19 (s, 9H), 0.88 (t, 3H, J ) 6.5
3300, 2900, 1590, 1420, 1250, 1110, 1030, 910, 790, 730 cm-1
;
Hz), 1.28 (s, 9H), 1.29-1.99 (m, 8H), 3.53 (d, 1H, J ) 8.3 Hz),
4.40 (dt, 1H, J ) 3.1, 8.3 Hz), 5.95 (s, 1H); IR (neat) 3300,
EIMS m/z (rel intensity) 463 (M+, 3), 444 (8), 265 (40), 197
2900, 1580, 1450, 1360, 1250, 1180, 1010, 910, 850, 730 cm-1
;
(100). Found: C, 72.91; H, 7.25. Calcd for C28H34O2SSi: C,
72.68; H, 7.41%. (SS,R)-4f: [R]18 +93.6 (c 0.07 in acetone);
EIMS m/z (rel intensity) 304 (M+, 1), 248 (24), 127 (90), 73
D
1H NMR δ 0.70 (s, 3H), 0.72-1.65 (m, 11H), 1.27 (d, 1H, J )
8.0 Hz), 2.33 (s, 3H), 4.27 (dt, 1H, J ) 4.8, 8.0 Hz), 7.10 (s,
1H), 7.18-7.52 (m, 14H); IR (neat) 3300, 2900, 1590, 1420,
1250, 1110, 1030, 910, 790, 730 cm-1; EIMS m/z (rel intensity)
463 (M+, 3), 444 (6), 265 (42), 197 (100). Found: C, 72.56; H,
7.52. Calcd for C28H34O2SSi: C, 72.68; H, 7.41%.
(100). Found: C, 58.93; H, 10.45. Calcd for C15H32O2SSi: C,
59.16; H, 10.59%. (SS,R)-4j: [R]22 +52.0 (c 0.46 in acetone);
D
1H NMR δ 0.22 (s, 9H), 0.90 (br, 3H), 1.24 (s, 9H), 1.20-1.80
(m, 8H), 1.95 (d, 1H, J ) 4.8 Hz), 4.64 (dt, 1H, J ) 4.8, 6.8
Hz), 6.34 (s, 1H); IR (neat) 3300, 2900, 1580, 1450, 1360, 1250,
1180, 1010, 910, 850, 730 cm-1; EIMS m/z (rel intensity) 248
(M+-C4H8, 18), 199 (8), 127 (90), 73 (100). Found: C, 59.21; H,
10.67. Calcd for C15H32O2SSi: C, 59.16; H, 10.59%.
(SS,S)- a n d (SS,R)-(E)-2-(p-Tolylsu lfin yl)-1-(tr ip h en yl-
silyl)-1-octen -3-ol (4g). The reaction was carried out as
described above except using 3c (113 mg, 0.27 mmol) and
hexanal (0.065 mL, 0.54 mmol). Usual workup gave the crude
product which was purified by column chromatography (silica
gel, hexane/ethyl acetate ) 90:10) to afford (SS,S)-4g (65 mg,
46%) and (SS,R)-4g (33 mg, 24%). (SS,S)-4g: mp 120-121 °C;
Rep r esen ta tive P r oced u r e for th e Con ver sion of (R)-
4a in to th e P r op a r gylic Alcoh ols 5a a n d Allylic Alcoh ols
6a w ith Tetr a bu tyla m m on iu m F lu or id e. To a solution of
(R)-4a (13 mg, 0.037 mmol) in THF (2.6 mL) was added a THF
solution of tetrabutylammonium fluoride (1.0 mol L-1, 0.039
mL, 0.039 mmol), which had been dried over molecular sieves
4A, at room temperature, and the mixture was stirred for 5
min. THF was then evaporated under reduced pressure and
the residue was purified by column chromatography (silica gel
3 g, hexane/ethyl acetate ) 99:1) to give (R)-5a (1.4 mg, 28%)
and (R)-6a (6.5 mg, 63%).
Rep r esen ta tive P r oced u r e for th e Con ver sion of 4a
in to th e P r op a r gylic Alcoh ol 5a a n d Allylic Alcoh ols 6a
w ith Na H. To a suspension of sodium hydride (19 mg, 0.48
mmol) in THF (0.5 mL) was added a (S)-4a (129 mg, 0.40
mmol) in THF (0.8 mL) at 0 °C, and the mixture was stirred
for 30 min, the solution was quenched with saturated aqueous
NH4Cl (3 mL) under vigorous stirring and the organic layer
was separated. The aqueous layer was extracted with CH2-
Cl2, and the combined organic extracts were washed with
brine, dried over MgSO4, filtered, and concentrated under
reduced pressure to give the crude product which was purified
by column chromatography (silica gel 11 g, hexane/ethyl
acetate ) 99:1) to give (R)-5a (41 mg, 83%) and (S)-6a (5.8
mg, 5%).
[R]23 +114.1 (c 0.16 in acetone); 1H NMR δ 0.40-1.15 (m,
D
11H), 2.23 (d, 1H, J ) 7.0 Hz), 2.41 (s, 3H), 4.12 (dt, 1H, J )
6.0, 7.0 Hz), 7.15 (s, 1H), 7.21-7.68 (m, 19H); IR (KBr) 3310,
3050, 2950, 2850, 1590, 1490, 1430, 1260, 1110, 910, 770, 730,
700 cm-1; EIMS m/z (rel intensity) 524 (M+, 0.5), 447 (3), 258
(38), 198 (100). Found: C, 75.81; H, 7.12. Calcd for C33H36O2-
SSi: C, 75.53; H, 6.91%. (SS,R)-4g: [R]23 +59.8 (c 0.08 in
D
1
acetone); H NMR δ 0.52-1.65 (m, 11H), 1.35 (br, 1H), 2.40
(s, 3H), 4.29 (t, 1H, J ) 8.5 Hz), 7.21-7.64 (m, 20H); IR (neat)
3300, 3050, 2950, 2850, 1590, 1490, 1430, 1260, 1110, 910, 770,
730, 700 cm-1; EIMS m/z (rel intensity) 524 (M+, 0.4), 315 (22),
258 (42), 199 (100). Found: C, 75.68; H, 7.12. Calcd for
C
33H36O2SSi: C, 75.53; H, 6.91%.
(SS,S)- a n d (SS,R)-(E)-4,4-Dim eth yl-2-(p-Tolylsu lfin yl)-
1-(tr ip h en ylsilyl)-1-p en ten -3-ol (4h ). The reaction was car-
ried out as described above except using 3c (47 mg, 0.11 mmol)
and 2,2-dimethylpropionaldehyde (0.024 mL, 0.22 mmol).
Usual workup gave the crude product which was purified by
column chromatography (silica gel, hexane/ethyl acetate ) 95:
5) to afford (SS,S)-4h (28 mg, 50%) and (SS,R)-4h (14 mg, 24%).
(SS,S)-4h : 1H NMR δ 0.72 (s, 9H), 2.48 (s, 3H), 2.88 (d, 1H, J
) 7.7 Hz), 3.94 (d, 1H, J ) 7.7 Hz), 7.08 (s, 1H), 7.25-7.69
(m, 19H); IR (neat) 3250, 2900, 1660, 1490, 1450, 1260, 1120,
1060, 970, 800 cm-1; EIMS m/z (rel intensity) 510 (M+, 0.5),
198 (100). Found: C, 75.39; H, 6.98. Calcd for C32H34O2SSi:
C, 75.25; H, 6.71%. (SS,R)-4h : δ 1.07 (s, 9H), 1.84 (d, 1H, J )
6.0 Hz), 2.41 (s, 3H), 4.16 (d, 1H, J ) 6.0 Hz), 7.20-7.65 (m,
20H); IR (neat) 3200, 2910, 1600, 1480, 1460, 1260, 1120, 1050,
970, 810 cm-1; EIMS m/z (rel intensity) 510 (M+, 0.5), 198
(100). Found: C, 75.51; H, 6.94. Calcd for C32H34O2SSi: C,
75.25; H, 6.71%.
Rep r esen ta tive P r oced u r e for th e Con ver sion of 4a
in to th e Tr im eth ylsilylp r op a r gylic Alcoh ol 8a u n d er
Th er m a l Con d ition s. A solution of (S)-4a (100 mg, 0.29
mmol) in toluene (2.0 mL) was heated under reflux for 1 h.
After the mixture was cooled, the solvent was evaporated
under reduced pressure and the residue was purified by
column chromatography (silica gel 12 g, hexane/ethyl acetate
) 95:5) to give (S)-8a (52 mg, 87%).
21
(R)-1-P h en yl-2-p r op yn -1-ol [(R)-5a ]. [R]
-26.7 (c 1.5
D
in CHCl3) lit.23 [R]22 -27.1 (c 2.4 in CHCl3); H NMR δ 2.15
1
D
(d, 1H, J ) 6.3 Hz), 2.65 (d, 1H, J ) 2.2 Hz), 5.45 (dd, 1H, J
) 2.2, 6.3 Hz), 7.30-7.60 (m, 5H); IR (neat) 3300, 3270, 2110
cm-1. MTPA ester of (R)-5a : 1H NMR δ 2.69 (d, 1H, J ) 2.1
Hz), 3.46 (s, 3H), 6.63 (d, 1H, J ) 2.2 Hz), 7.25-7.68 (m, 10H).
(S)-1-P h en yl-2-p r op yn -1-ol [(S)-5a ]. [R]22D +26.1 (c 1.6 in
CHCl3). MTPA ester of (S)-5a : 1H NMR δ 2.73 (d, 1H, J ) 2.2
Hz), 3.59 (s, 3H), 6.63 (d, 1H, J ) 2.3 Hz), 7.25-7.49 (m, 10H).
(R)-1-Octyn -3-ol [(R)-5c]. [R]22D +20.5 (c 1.65 in Et2O) lit.1k
(SS,S)- a n d (SS,R)-(E)-2-(ter t-Bu tylsu lfin yl)-1-p h en yl-3-
(tr im eth ylsilyl)-2-p r op en -1-ol (4i). The reaction was carried
out as described above except using 3d (31 mg, 0.15 mmol)
and benzaldehyde (0.031 mL, 0.30 mmol). Usual workup gave
the crude product which was purified by column chromatog-
raphy (silica gel, hexane/ethyl acetate ) 95:5) to afford (SS,S)-
4i (14 mg, 30%) and (SS,R)-4i (28 mg, 58%). (SS,S)-4i: 1H NMR
δ 0.12 (s, 9H), 1.18 (s, 9H), 2.97 (d, 1H, J ) 5.5 Hz), 5.82 (d,
1H, J ) 5.5 Hz), 6.59 (s, 1H), 7.27-7.42 (m, 5H); IR (KBr)
3250, 2950, 1660, 1450, 1360, 1250, 1170, 1060, 1010, 960, 850,
740, 700 cm-1; EIMS m/z (rel intensity) 310 (M+, 5), 178 (24),
105 (100). Found: C, 62.11; H, 8.21. Calcd for C16H26O2SSi:
C, 61.89; H, 8.44%. (SS,R)-4i: δ 0.13 (s, 9H), 1.28 (s, 9H), 4.02
(d, 1H, J ) 7.9 Hz), 5.56 (d, 1H, J ) 7.9 Hz), 6.33 (s, 1H),
7.26-7.45 (m, 5H); IR (KBr) 3250, 2950, 1600, 1450, 1360,
1250, 1170, 1060, 1010, 960, 850, 740, 700 cm-1; EIMS m/z
[R]21 -18.8 (c 1.30 in Et2O) for (S)-isomer (84% ee); 1H NMR
D
δ 0.88-1.78 (m, 11H), 1.88 (d, 1H, J ) 1.9 Hz), 2.45 (d, 1H, J
) 1.9 Hz), 4.30-4.41 (br, 1H); IR (neat) 3400, 3350, 2950, 1040,
650 cm-1. MTPA ester of (R)-5c: 1H NMR δ 0.78-1.85 (m,
11H), 2.53 (d, 1H, J ) 2.3 Hz), 3.60 (s, 3H), 5.54 (dt, 1H, J )
2.3, 6.5 Hz), 7.31-7.60 (m, 5H).
(23) Voila, A.; Dudding, G. F.; Proverb, R. J . J . Am. Chem. Soc. 1977,
99, 7390-7392.

Elimination Reaction of Vinyl Sulfoxides
J . Org. Chem., Vol. 67, No. 3, 2002 647
(S)-1-Octyn -3-ol [(S)-5c]. [R]22 -19.2 (c 1.50 in Et2O).
(d, 1H, J ) 7.1 Hz), 5.47 (d, 1H, J ) 7.1 Hz), 7.31-7.61 (m,
5H); IR (neat) 3300, 2950, 2160, 1490, 1450, 1250, 1040, 980,
840, 760, 700 cm-1. Anal. Calcd for C12H16OSi: C, 62.02; H,
10.41. Found: C, 62.21; H, 10.34. MTPA ester of (S)-8a : 1H
NMR δ 0.18 (s, 9H), 3.47 (s, 3H), 6.64 (s, 1H), 7.30-7.58 (m,
10H).
D
MTPA ester of (S)-5c: 1H NMR δ 0.80-1.90 (m, 11H), 2.47
(d, 1H, J ) 2.7 Hz), 3.54 (s, 3H), 5.50 (dt, 1H, J ) 2.2, 6.7 Hz),
7.32-7.56 (m, 5H).
(SS,S)-1-P h en yl-2-(p-tolylsu lfin yl)-2-p r op en -1-ol [(S)-
6a ]. mp 129-130 °C; [R]21D +104.7 (c 0.48 in acetone); 1H NMR
δ 2.45 (s, 3H), 3.78 (d, 1H, J ) 2.7 Hz), 5.30 (d, 1H, J ) 2.7
Hz), 5.49 (s, 1H), 6.07 (s, 1H), 7.08-7.58 (m, 9H); IR (KBr)
3350, 2920, 2850, 1620, 1590, 1490, 1450, 1280, 1080, 1060,
1020, 920, 900, 840, 910, 760, 700 cm-1; EIMS m/z (rel
intensity) 272 (M+, 1), 140 (95), 133 (100), 92 (58). Found: C,
70.48; H, 6.00. Calcd for C16H16O2S: C, 70.56; H, 5.92%.
(SS,R)-1-P h en yl-2-(p-tolylsu lfin yl)-2-p r op en -1-ol [(R)-
(R)-1-P h en yl-3-t r im et h ylsilyl-2-p r op yn -1-ol [(R)-8a ].
[R]21D +21.0 (c 1.11 in CHCl3). MTPA ester of (R)-8a : 1H NMR
δ 0.20 (s, 9H), 3.60 (s, 3H), 6.66 (s, 1H), 7.28-7.52 (m, 10H).
(S)-4-Tr im eth ylsilyl-3-bu tyn -2-ol [(S)-8b]. [R]22 -23.9
D
(c 0.64 in CHCl3) lit.24 [R]22D -25.9 (c 3.12 in CHCl3); 1H NMR
δ 0.18 (s, 9H), 1.46 (d, 3H, J ) 6.7 Hz), 1.87 (d, 1H, J ) 5.2
Hz), 4.53 (dq, 1H, J ) 5.2, 6.7 Hz); IR (neat) 3320, 2960, 2170,
1420, 1370, 1320, 1250, 1120, 1080, 1040, 940, 860, 840, 760
cm-1. MTPA ester of (S)-8b: 1H NMR δ 0.15 (s, 9H), 1.57 (d,
3H, J ) 6.8 Hz), 3.56 (s, 3H), 5.63 (q, 1H, J ) 6.8 Hz), 7.38-
7.50 (m, 5H).
6a ]. [R]24 +205.7 (c 0.60 in acetone); 1H NMR δ 2.43 (s, 3H),
D
3.12 (d, 1H, J ) 5.0 Hz), 5.17 (d, 1H, J ) 5.0 Hz), 5.40 (s, 1H),
6.04 (s, 1H), 7.17-7.30 (m, 7H), 7.58 (d, 2H, J ) 6.5 Hz); IR
(KBr) 3400, 2900, 1890, 1630, 1590, 1490, 1450, 1360, 1310,
1280, 1240, 1200, 1180, 1140, 1080, 1030, 1020, 950, 910, 840,
820, 770, 700 cm-1; EIMS m/z (rel intensity) 272 (M+, 15), 133
(100). Found: C, 70.58; H, 6.13. Calcd for C16H16O2S: C, 70.56;
H, 5.92%.
(R)-4-Tr im eth ylsilyl-3-bu tyn -2-ol [(R)-8b]. [R]22 +24.7
D
(c 0.34 in CHCl3). MTPA ester of (R)-8b: 1H NMR δ 0.15 (s,
9H), 1.57 (d, 3H, J ) 6.8 Hz), 3.56 (s, 3H), 5.63 (q, 1H, J ) 6.8
Hz), 7.38-7.50 (m, 5H).
(SS,S)-2-(p-Tolylsu lfin yl)-1-octen -3-ol [(S)-6c]. 1H NMR
δ 0.78-1.74 (m, 11H), 1.80-2.10 (br, 1H), 2.40 (s, 3H), 4.15
(t, 1H, J ) 6.2 Hz), 5.84 (s, 1H), 6.06 (s, 1H), 7.29 (d, 2H, J )
8.2 Hz), 7.56 (d, 2H, J ) 8.2 Hz); IR (neat) 3350, 2950, 1080,
(S)-1-Tr im eth ylsilyl-1-octyn -3-ol [(S)-8c]. [R]21D -14.3 (c
1
0.95 in CHCl3); H NMR δ 0.16 (s, 9H), 0.88 (t, 3H, J ) 6.6
Hz), 1.20-1.75 (m, 8H), 1.76 (d, 1H, J ) 5.6 Hz), 4.34 (dt, 1H,
J ) 5.6, 6.5 Hz); IR (neat) 3300, 2950, 2200, 1450, 1250, 1120,
1030, 840, 760 cm-1; EIMS m/z (rel intensity) 183 (M+-CH3,
38), 125 (57), 73 (100). Anal. Calcd for C11H22OSi: C, 66.60;
H, 11.18. Found: C, 66.49; H, 11.06. MTPA ester of (S)-8c:
1H NMR δ 0.15 (s, 9H), 0.82-1.80 (m, 11H), 3.56 (s, 3H), 5.50
(t, 1H, J ) 6.8 Hz), 7.35-7.60 (m, 5H).
1040, 780 cm-1
.
(SS,R)-2-(p -Tolylsu lfin yl)-1-oct en -3-ol [(R)-6c]. [R]21
D
+134.9 (c 0.17 in acetone); 1H NMR δ 0.80-1.65 (m, 11H), 2.39
(s, 3H), 2.86 (d, 1H, J ) 3.4 Hz), 4.08-4.20 (m, 1H), 5.84 (s,
1H), 6.03 (s, 1H), 7.29 (d, 2H, J ) 7.8 Hz), 7.56 (d, 2H, J ) 7.8
Hz); IR (neat) 3400, 2950, 1080, 1040, 940, 780 cm-1; EIMS
m/z (rel intensity) 266 (M+, 16), 249 (28), 140 (100). Anal. Calcd
for C15H22O2S: C, 67.63; H, 8.32. Found: C, 67.75; H, 8.52.
(SS,R)-2-(ter t-Bu tylsu lfin yl)-1-octen -3-ol [(R)-6j]. 1H NMR
δ 0.65-1.80 (m, 11H), 1.24 (s, 9H), 3.30 (d, 1H, J ) 3.8 Hz),
4.40-4.50 (m, 1H), 5.63 (d, 1H, J ) 1.1 Hz), 5.87 (d, 1H, J )
1.1 Hz); IR (neat) 3400, 3000, 1470, 1380, 1180, 1030, 940,
740 cm-1; EIMS m/z (rel intensity) 176 (M+-C4H8, 38), 158 (40),
57 (100). Anal. Calcd for C12H24O2S: C, 62.02; H, 10.41.
Found: C, 62.21; H, 10.34.
(R)-1-Tr im eth ylsilyl-1-octyn -3-ol [(R)-8c]. [R]21 +13.6
D
(c 1.10 in CHCl3). MTPA ester of (R)-8c: 1H NMR δ 0.14 (s,
9H), 0.80-1.80 (m, 11H), 3.59 (s, 3H), 5.53 (t, 1H, J ) 6.7 Hz),
7.35-7.60 (m, 5H).
Su p p or tin g In for m a tion Ava ila ble: Calculation results
of 9 and 10. The NPA and the NBO analyses of the stabilizing
effects of the silicon in transition states. This material is
available free of charge via the Internet at http://pubs.acs.org.
J O0157223
(S)-1-P h en yl-3-t r im et h ylsilyl-2-p r op yn -1-ol [(S)-8a ].
[R]21 -20.4 (c 1.05 in CHCl3) lit.3b [R]25 +10.3 (c 3.39 in
D
D
(24) Burgess, K.; J ennings, L. D. J . Am. Chem. Soc. 1991, 113, 3,
6129-6139.
1
CHCl3) for (R)-isomer (21% ee); H NMR δ 0.21 (s, 9H), 2.18