Ring-opening reactions of α,β-epoxy silanes with organocopper reagents: Reaction at carbon or silicon?

Full text of DOI:10.1021/jo9613186

J . Org. Chem. 1996, 61, 8655-8658
8655
The reasons for the preference for R opening of the R,â-
epoxy silanes are not completely obvious. The R-position
is frequently the more hindered, and ring opening at the
â-position (under electrophilic conditions) might be ex-
pected to produce a highly stabilized â-silyl cation.19
However, as we first pointed out in 1976, the lack of
â-opening, although remarkable, is perhaps less surpris-
ing in view of the relative orientation of the C-Si bond
and the â-C-O bond which greatly deviates from the
parallel alignment that is favorable for stabilization of a
developing positive â-charge by the silicon.12a The high
reactivity of Me3SiCH2X toward nucleophilic displace-
ments has also been noted.20 Both the reactivity of
Me3SiCH2X20c and the R-opening of R,â-epoxy si-
lanes6ad,8a,12bc,13c,21 have been rationalized by assuming
Rin g-Op en in g Rea ction s of r,â-Ep oxy
Sila n es w ith Or ga n ocop p er Rea gen ts:
Rea ction a t Ca r bon or Silicon ?
Paul F. Hudrlik,* Da Ma, Rama S. Bhamidipati, and
Anne M. Hudrlik
Department of Chemistry, Howard University,
Washington, D.C. 20059
Received J uly 12, 1996
R,â-Epoxy silanes react with a wide variety of reagents
via ring opening R to silicon.1 These reactions have been
found to have a variety of uses in organic synthesis.1 A
number of years ago, we introduced a stereospecific
synthesis of olefins2a and heteroatom-substituted olefins2bc
based on these ring opening reactions coupled with
stereospecific3,4 â-elimination reactions of the resulting
â-hydroxy silanes. R,â-Epoxy silanes also have potential
uses for the preparation of homochiral building blocks
in asymmetric synthesis due to the effect of silicon on
the stereochemistry of epoxidation reactions, particularly
the Sharpless asymmetric epoxidation.5
(8) (a) Eisch, J . J .; Galle, J . E. J . Org. Chem. 1976, 41, 2615-2621.
(b) Eisch, J . J .; Galle, J . E. J . Organomet. Chem. 1988, 341, 293-313.
(c) Eisch, J . J .; Liu, Z.-R.; Singh, M. J . Org. Chem. 1992, 57, 1618-
1621.
(9) (a) Yamamoto, K.; Kimura, T.; Tomo, Y. Tetrahedron Lett. 1984,
25, 2155-2158. (b) Nativi, C.; Ravida`, N.; Ricci, A.; Seconi, G.; Taddei,
M. J . Org. Chem. 1991, 56, 1951-1955.
(10) (a) Schaumann, E.; Kirschning, A. J . Chem. Soc., Perkin Trans.
1 1990, 419-421. (b) J ankowski, P.; Raubo, P.; Wicha, J . Synlett 1994,
985-992 and references cited therein.
R-Ring opening of R,â-epoxy silanes has been observed
under both nucleophilic and electrophilic conditions. The
6
reaction was first observed in 1963 using LiAlH4 and
(11) Okamoto, S.; Shimazaki, T.; Kobayashi, Y.; Sato, F. Tetrahedron
Lett. 1987, 28, 2033-2036.
then in 1975, in a paper that introduced the olefin
synthesis,2a using organocopper reagents. Additional
examples of R-ring opening of R,â-epoxy silanes have been
reported with organocopper reagents,7 as well as with a
variety of other reagents including other hydride reagents
(e.g., i-Bu2AlH,8 AlH36e,9), stabilized organolithium rea-
gents,7h,10 R3SnLi,11 magnesium halides,12 hydrogen
halides,13 SiF4,14 RCO2H,2b,4b,15 ROH/acid,16 CH3CN/
acid,2b amines,2c azides,17 KSCN,6d and organosulfur
reagents.18
(12) (a) Hudrlik, P. F.; Misra, R. N.; Withers, G. P.; Hudrlik, A. M.;
Rona, R. J .; Arcoleo, J . P. Tetrahedron Lett. 1976, 1453-1456. (b)
Obayashi, M.; Utimoto, K.; Nozaki, H. Tetrahedron Lett. 1978, 1383-
1386. (c) Obayashi, M.; Utimoto, K.; Nozaki, H. Bull. Chem. Soc. J pn.
1979, 52, 2646-2652. (d) Okamoto, S.; Shimazaki, T.; Kobayashi, Y.;
Sato, F. Tetrahedron Lett. 1987, 28, 2033-2036.
(13) Many examples including refs 2b, 6b, 6d, 7g, 12b, 12c, and the
following: (a) Hudrlik, P. F.; Arcoleo, J . P.; Schwartz, R. H.; Misra, R.
N.; Rona, R. J . Tetrahedron Lett. 1977, 591-594. (b) Obayashi, M.;
Utimoto, K.; Nozaki, H. Bull. Chem. Soc. J pn. 1979, 52, 1760-1764.
(c) Berti, G.; Canedoli, S.; Crotti, P.; Macchia, F. J . Chem. Soc., Perkin
Trans. 1 1984, 1183-1188. (d) Burke, S. D.; Piscopio, A. D.; Kort, M.
E.; Matulenko, M. A.; Parker, M. H.; Armistead, D. M.; Shankaran,
K. J . Org. Chem. 1994, 59, 332-347.
(14) Shimizu, M.; Yoshioka, H. Tetrahedron Lett. 1989, 30, 967-
970.
(15) Burford, C.; Cooke, F.; Roy, G.; Magnus, P. Tetrahedron 1983,
39, 867-876.
(16) Many examples including refs 2b, 4b, 6b, 6d, 13a, and the
following: (a) Ishikawa, M.; Nakagawa, K.; Katayama, S.; Kumada,
M. J . Am. Chem. Soc. 1981, 103, 4170-4174. (b) Hudrlik, P. F.;
Hudrlik, A. M.; Kulkarni, A. K. J . Am. Chem. Soc. 1982, 104, 6809-
6811. (c) Hudrlik, P. F.; Holmes, P. E.; Hudrlik, A. M. Tetrahedron
Lett. 1988, 29, 6395-6398.
(1) Review: Hudrlik, P. F.; Hudrlik, A. M. In Advances in Silicon
Chemistry; Larson, G. L., Ed.; J AI Press: Greenwich, CT, 1993; Vol.
2, pp 1-89.
(2) (a) Hudrlik, P. F.; Peterson, D.; Rona, R. J . J . Org. Chem. 1975,
40, 2263-2264. (b) Hudrlik, P. F.; Hudrlik, A. M.; Rona, R. J .; Misra,
R. N.; Withers, G. P. J . Am. Chem. Soc. 1977, 99, 1993-1996. (c)
Hudrlik, P. F.; Hudrlik, A. M.; Kulkarni, A. K. Tetrahedron Lett. 1985,
26, 139-142.
(3) Hudrlik, P. F.; Peterson, D. J . Am. Chem. Soc. 1975, 97, 1464-
1468.
(4) Syn-elimination with basic conditions;2a,3 anti-elimination with
acid conditions;2a,3 anti-elimination by conversion of the hydroxyl to a
good leaving group and treatment with fluoride, e.g., see: (a) Luo, F.-
T.; Negishi, E. J . Org. Chem. 1983, 48, 5144-5146. See also: (b)
Croudace, M. C.; Schore, N. E. J . Org. Chem. 1981, 46, 5357-5363.
(5) Kitano, Y.; Matsumoto, T.; Sato, F. Tetrahedron 1988, 44, 4073-
4086. Carlier, P. R.; Mungall, W. S.; Schro¨der, G.; Sharpless, K. B. J .
Am. Chem. Soc. 1988, 110, 2978-2979. This topic is reviewed in ref 1.
(6) (a) Eisch, J . J .; Trainor, J . T. J . Org. Chem. 1963, 28, 2870-
2876. Many other examples including (b) Robbins, C. M.; Whitham,
G. H. J . Chem. Soc. D 1976, 697-698. (c) Fristad, W. E.; Bailey, T. R.;
Paquette, L. A. J . Org. Chem. 1980, 45, 3028-3037. (d) Davis, A. P.;
Hughes, G. J .; Lowndes, P. R.; Robbins, C. M.; Thomas, E. J .; Whitham,
G. H. J . Chem. Soc., Perkin Trans. 1 1981, 1934-1941. (e) Takeda,
Y.; Matsumoto, T.; Sato, F. J . Org. Chem. 1986, 51, 4728-4731. (f)
Hudrlik, P. F.; Agwaramgbo, E. L. O.; Hudrlik, A. M. J . Org. Chem.
1989, 54, 5613-5618.
(7) (a) Shimizu, N.; Shibata, F.; Tsuno, Y. Chem. Lett. 1985, 1593-
1594. (b) Kitano, Y.; Matsumoto, T; Sato, F. J . Chem. Soc., Chem.
Commun. 1986, 1323-1325. (c) Tamao, K.; Najako, E.; Ito, Y. J . Org.
Chem. 1987, 52, 4412-4414. (d) Alexakis, A.; J achiet, D. Tetrahedron
Lett. 1988, 29, 217-218. (e) Alexakis, A.; Mangeney, P.; Ghribi, A.;
J achiet, D.; Normant, J . F. Philos. Trans. R. Soc. London, Ser. A 1988,
326, 557-564. (f) Alexakis, A.; J achiet, D. Tetrahedron 1989, 45, 381-
389. (g) Chou, S.-S. P.; Kuo, H.-L.; Wang, C.-J .; Tsai, C.-Y.; Sun, C.-
M. J . Org. Chem. 1989, 54, 868-872. (h) Zhang, Y.; Miller, J . A.;
Negishi, E. J . Org. Chem. 1989, 54, 2043-2044. (i) Soderquist, J . A.;
Santiago, B. Tetrahedron Lett. 1989, 30, 5693-5696. (j) Shimizu, N.;
Imazu, S.; Shibata, F.; Tsuno, Y. Bull. Chem. Soc. J pn. 1991, 64, 1122-
1128. (k) Chauret, D. C.; Chong, J . M. Tetrahedron Lett. 1993, 34,
3695-3698.
(17) (a) Tomoda, S.; Matsumoto, Y.; Takeuchi, Y.; Nomura, Y. Bull.
Chem. Soc. J pn. 1986, 59, 3283-3284. (b) Tomoda, S.; Matsumoto,
Y.; Takeuchi, Y.; Nomura, Y. Chem. Lett. 1986, 1193-1196. (c)
Chakraborty, T. K.; Reddy, G. V. Tetrahedron Lett. 1990, 31, 1335-
1338. (d) Chakraborty, T. K.; Reddy, G. V. Tetrahedron Lett. 1991, 32,
679-682.
(18) (a) Hudrlik, P. F.; Kulkarni, A. K., unpublished work. (b)
Okamoto, S.; Yoshino, T.; Tsujiyama, H.; Sato, F. Tetrahedron Lett.
1991, 32, 5793-5796. (c) Raubo, P.; Wicha, J . Synlett 1993, 25-26.
(19) â-Opening has been observed in some cases, particularly where
steric factors have been important: refs 1, 7k, 8c, 18c and (a)
J ankowski, P.; Wicha, J . J . Chem. Soc. D 1992, 802-803. (b) Eisch, J .
J .; Chiu, C. S. Heteroat. Chem. 1994, 5, 265-274. (c) Lipshutz, B. H.;
Lindsley, C.; Susfalk, R.; Gross, T. Tetrahedron Lett. 1994, 35, 8999-
9002. (d) Horiuchi, Y.; Taniguchi, M.; Oshima, K.; Utimoto, K.
Tetrahedron Lett. 1995, 36, 5353-5356. (e) Adiwidjaja, G.; Flo¨rke, H.;
Kirschning, A.; Schaumann, E. Tetrahedron Lett. 1995, 36, 8771-8774.
(20) (a) Whitmore, F. C.; Sommer, L. H. J . Am. Chem. Soc. 1946,
68, 481-484. (b) Cooper, G. D.; Prober, M. J . Am. Chem. Soc. 1954,
76, 3943-3945. (c) Eaborn, C.; J effrey, J . C. J . Chem. Soc. 1954, 4266-
4268. (d) Miller, V. B.; Neiman, M. B.; Savitskii, A. V.; Mironov, V. F.
Dokl. Akad. Nauk SSSR 1955, 101, 495-497; Chem. Abstr. 1956, 50,
3217b. (e) Eaborn, C.; J effrey, J . C. J . Chem. Soc. 1957, 137-144. (f)
Huang, C.-T.; Wang, P.-J . Hua Hsueh Hsueh Pao 1959, 25, 330-340;
Chem. Abstr. 1960, 54, 16375d. See also: (g) Stang, P. J .; Ladika, M.;
Apeloig, Y.; Stanger, A.; Schiavelli, M. D.; Hughey, M. R. J . Am. Chem.
Soc. 1982, 104, 6852-6854.
(21) (a) Richer, J .-C.; Poirier, M.-A.; Maroni, Y.; Manuel, G. Can. J .
Chem. 1978, 56, 2049-2052. (b) Crotti, P.; Macchia, F.; Pizzabiocca,
A.; Renzi, G.; Speranza, M. J . Chem. Soc., Chem. Commun. 1986, 485-
487.
S0022-3263(96)01318-7 CCC: $12.00 © 1996 American Chemical Society

8656 J . Org. Chem., Vol. 61, No. 24, 1996
Notes
Sch em e 1
Sch em e 2
initial coordination of the nucleophile with both silicon
and carbon. Coordination of the nucleophile with silicon
followed by 1,2-rearrangement to the R-carbon6d,12b,21b,22
has also been suggested for the R-opening reactions.23,24
We report here a test of the latter suggestion (coordi-
nation followed by 1,2-rearrangement) for the reactions
of R,â-epoxy silanes with organocopper reagents.25 We
have studied the reactions of the PhMe2Si and Ph2MeSi
epoxy silanes 1 and 5 with methylcopper reagents (MeLi/
CuI 2:1) (see Scheme 1).26 If pentacoordinated interme-
diates 2 and 6 were involved, R-phenyl-â-hydroxy silanes
3 and 7 should be formed rather than R-methyl-â-hydroxy
silanes 4 and 8, since phenyl is a better migrating group
than methyl.28 The R-phenyl-â-hydroxy silanes 3 and 7
might be expected to undergo â-elimination or desilyla-
tion reactions more rapidly than the R-methyl-â-hydroxy
silanes 4 and 8; therefore, 1-phenyl-1-octene (9) and
1-phenyl-2-octanol (10) might also be formed.
(Z)-1-(Trimethylsilyl)-1,2-epoxyoctane (13), used as a
control and as a starting material for the preparation of
comparison samples, and the corresponding phenyldi-
methylsilyl (1) and diphenylmethylsilyl (5) epoxides were
prepared as shown in Scheme 2.
Our first attempts to prepare comparison samples of
R-phenyl-â-hydroxy silanes 3 and 7 by ring opening of
epoxy silanes 13 and 1 with copper reagents derived from
PhLi were unsuccessful. Treatment of epoxy silanes 13
and 1 with PhLi/CuI (2:1) and with PhLi/CuCN (2:1) led
to no detectable â-hydroxy silanes (3 and 7, respectively).
In all of the cases, small amounts of 1-phenyl-1-octene
(9) as well as considerable amounts of biphenyl were
present in the products. In the case of the PhMe2Si
epoxide 1, diphenyldimethylsilane was also observed in
the product mixtures.
Early attempts to open R,â-epoxy silanes with alkenyl
organocopper reagents were reported to be unsuc-
cessful.7df,29 Alexakis and co-workers have found that
such reactions can be carried out with the assistance of
BF3‚Et2O.7d-f We were able to prepare 3 and 7 using the
Alexakis procedure. Treatment of epoxy silane 13 with
PhLi/CuI (2:1) in the presence of BF3‚Et2O produced the
â-hydroxy silane 3 in 86% yield. Treatment of epoxy
silane 1 with PhLi/CuI (2:1) in the presence of BF3‚Et2O
produced the â-hydroxy silane 7 in 58% yield. Compari-
son samples of the olefins 9z and 9e were prepared by
(22) Eisch, J . J .; Chiu, C. S. J . Organomet. Chem. 1988, 358, C1-
C5.
(23) Lowering the transition state energy of an SN2 reaction at the
carbon R to silicon has been compared to stabilization of an “anion” at
the R-carbon. Overlap involving the empty, antibonding orbitals of the
Me-Si bond (in the case of a Me3Si group) with the filled orbitals of
the carbon-metal bond has been invoked: Fleming, I. In Comprehen-
sive Organic Chemistry; Barton, D., Ollis, W. D., Eds.; Pergamon
Press: Oxford, 1979; Vol. 3, pp 541-686 (especially pp 545-546).
(24) Rearrangements of R-substituted organosilicon compounds with
migration of an organic group from silicon to carbon are well-known:
(a) Hudrlik, P. F.; Abdallah, Y. M.; Kulkarni, A. K.; Hudrlik, A. M. J .
Org. Chem. 1992, 57, 6552-6556 and references cited therein. (b)
Hudrlik, P. F.; Abdallah, Y. M.; Hudrlik, A. M. Tetrahedron Lett. 1992,
33, 6743-6746. (c) A precedent for 1,2-rearrangement from silicon to
the R-carbon of an epoxy silane is the reactions of some â-substituted
epoxy (phenyldimethyl)silanes with EtAlCl2, Me2AlCl, Et2AlCl, or Me3-
Al which resulted in modest yields of phenyl-substituted olefins:
Fleming, I.; Newton, T. W. J . Chem. Soc., Perkin Trans. 1 1984, 119-
123. (In contrast, reaction of triphenylsilylethylene oxide with MeAlCl2
resulted in the chlorohydrin from â-opening of the epoxide (ref 19b)).
(25) The mechanism of substitution reactions of organocopper
reagents is discussed in the following: Lipshutz, B. H.; Sengupta, S.
Org. React. 1992, 41, 135-631.
(26) When this work was begun, the only example of reaction of a
Ph-Si epoxy silane with an organocopper reagent was in the disserta-
tion of one of the authors.27 Two additional examples have since been
reported.7k In these cases, the isolated product was from direct epoxide
opening; the possibility of rearrangement was not addressed.
(27) Bhamidipati, R. S. Ph.D. Thesis, Howard University, Wash-
ington, DC, 1991.
(28) For example, see ref 24.
(29) Paquette, L. A.; Yan, T.-H.; Wells, G. J . J . Org. Chem. 1984,
49, 3610-3617.

Notes
J . Org. Chem., Vol. 61, No. 24, 1996 8657
Sch em e 3
â-elimination reactions of the â-hydroxy silanes 3 and 7.
A â-elimination reaction of 3 either with KH/THF or with
KH/ether gave (Z)-1-phenyl-1-octene (9z)30 accompanied
by an unidentified byproduct. A â-elimination reaction
of 7 with BF3‚Et2O/CH2Cl2 gave (E)-1-phenyl-1-octene
(9e)31 in 95% yield (see Scheme 3). A sample of (E)-1-
phenyl-1-octene (9e) was also prepared from 1-phenyl-
1-octanol by treatment with CuSO4 (78% yield).32
Epoxy silanes 13, 1, and 5 were each treated with
MeLi/CuI (2:1) in ether. The product from epoxy silane
13 was 2-(trimethylsilyl)-3-nonanol (18), as expected (76%
yield). The product from epoxy silane 1 was shown to
be 2-(phenyldimethylsilyl)-3-nonanol (4), and the product
from epoxy silane 5 was shown to be 2-(diphenylmeth-
ylsilyl)-3-nonanol (8).
1H NMR spectrum showed predominantly peaks due to
the â-hydroxy silane 8, with a very small multiplet at
about δ 1.5 and two very small singlets about 2.6-2.7.
No signals from the comparison compounds 7, 9e, 9z, or
10 were visible. The GC trace showed predominantly one
peak, with the maximum amount of comparison com-
pounds 7, 9z, and 9e at 2%, <1%, and 4%, respectively.
Diphenyldimethylsilane, which was present in the
product mixture from the reaction of the PhMe2Si epoxide
1 with PhLi/CuI, was not observed in the reaction
mixture from epoxide 5 with MeLi/CuI. The formation
of diphenyldimethylsilane from the reactions of epoxide
1 with PhLi/CuI and PhLi/CuCN suggests the possibility
that pentacoordinated intermediates such as 6 under
some conditions are more likely to undergo C-Si bond
breaking rather than rearrangement.
These results indicate that the ring-opening reactions
of epoxy silanes 1 and 5 with MeLi/CuI give the R-methyl-
â-hydroxy silanes 4 and 8, respectively, with no detect-
able R-phenyl-â-hydroxy silanes 3 or 7 or derived â-
elimination or desilylation products. Consequently,
whether or not pentacoordinate intermediates 2 and 6
are formed in these reactions, they do not appear to be
part of the product-determining pathway (to products 4
and 8). Initial coordination of the nucleophile with both
carbon and silicon remains a possibility.
2-(Phenyldimethylsilyl)-3-nonanol (4) was isolated af-
ter chromatography in 67% yield from the reaction with
epoxide 1. 2-(Diphenylmethylsilyl)-3-nonanol (8) was
isolated after chromatography in 57% yield from the
reaction with epoxide 5. Compounds 4 and 8 were
Exp er im en ta l Section
1
identified from their IR, H NMR, 13C NMR, and mass
1
Gen er a l. All of the reactions were carried out under nitro-
gen, and liquid transfers were carried out with nitrogen-flushed
syringes. The verb “concentrated” refers to removal of solvent
on the rotary evaporator. Column chromatography was per-
formed on Florisil (60-100 mesh, Fisher) or on silica gel (60 Å,
200-425 mesh, Fisher). GC analyses were performed with a
10% OV-101 silicone column on 80/100 mesh Gas-chrom Q, 2.6
m × 2.5 mm glass column (column S-3) or a Supelco SPB-1 30
m × 0.25 mm capillary column, film thickness 1.0 µm (column
C-4); the retention time of a hydrocarbon is sometimes included.
NMR spectra (1H at 300 MHz and 13C at 75 MHz) were obtained
in CDCl3; chemical shifts are reported in δ relative to TMS (δ
0.00) for 1H NMR measurements unless otherwise specified and
to CDCl3 (δ 77.000) for 13C NMR measurements. Assignments
in the 13C NMR spectra were made by DEPT 45, 90, and 135.
High-resolution mass spectra (HRMS) were determined by the
Midwest Center for Mass Spectrometry, University of Nebraska.
Anhydrous ether and THF were distilled from sodium and
benzophenone. CuI (Aldrich) was 99.999%. m-CPBA (Aldrich,
55-65%) was assumed to be 60%. Methyllithium (low halide)
in diethyl ether was obtained from Aldrich. (1-Octynyl)trimeth-
ylsilane (11)33 and (1-octynyl)phenyldimethylsilane (14)34 were
prepared from 1-octyne by treatment with methyllithium fol-
lowed by trimethylchlorosilane and phenyldimethylchlorosilane,
respectively. (Z)-(1-Octenyl)trimethylsilane (12)33,35 and (Z)-(1-
octenyl)phenyldimethylsilane (15)36 were prepared from octyn-
spectra. In particular, the H NMR of 4 showed a three-
proton doublet at δ 1.037 (J ) 7 Hz), and the 13C NMR
(with DEPT) showed four CH3 groups at δ -3.890,
1
-3.802, 7.903, and 13.972; the H NMR of 8 showed a
doublet at δ 1.111 (J ) 7.5 Hz), and the 13C NMR (with
DEPT) showed three CH3 groups at δ -5.080, 8.041, and
14.012.
The crude products from the reactions of epoxy silanes
1
1 and 5 with MeLi/CuI were compared by GC and by H
NMR with (E)- and (Z)-1-phenyl-1-octene (9e and 9z),
with 1-phenyl-2-octanol (10), and with the R-phenyl-â-
hydroxy silanes (3 in the case of epoxy silane 1, and 7 in
the case of epoxy silane 5). In the case of the crude
product from epoxy silane 1, the 1H NMR spectrum
showed predominantly peaks due to the â-hydroxy silane
4, with only a few additional singlets around δ 0.0. No
signals from the comparison compounds 3, 9e, 9z, or 10
were visible. The GC trace showed predominantly one
peak, with the maximum amount of comparison com-
pounds 3, 9z, and 9e at 2%, <1%, and <1%, respectively.
In the case of the crude product from epoxy silane 5, the
(30) Kauffmann, T.; Rauch, E.; Schulz, J . Chem. Ber. 1973, 106,
1612-1617.
(31) Yamane, T.; Kikukawa, K.; Takagi, M.; Matsuda, T. Tetrahe-
dron 1973, 29, 955-962. Mixer, R. Y.; Young, W. G. J . Am. Chem.
Soc. 1956, 78, 3379-3384.
(33) Uchida, K.; Utimoto, K.; Nozaki, H. J . Org. Chem. 1976, 41,
2215-2217.
(34) Hayami, H.; Oshima, K.; Nozaki, H. Tetrahedron Lett. 1984,
25, 4433-4436. Oda, H.; Sato, M.; Morizawa, Y.; Oshima, K.; Nozaki,
H. Tetrahedron 1985, 41, 3257-3268.
(32) Tanis, S. P.; Abdallah, Y. M. Synth. Commun. 1986, 16, 251-
259.

8658 J . Org. Chem., Vol. 61, No. 24, 1996
Notes
ylsilanes 11 and 14, respectively, by treatment with i-Bu2AlH.
(Z)-1-(Trimethylsilyl)-1,2-epoxyoctane (13)2b,37 was prepared
from vinylsilane 12 by treatment with m-CPBA. 1-Phenyl-2-
octanol (10)38 was prepared from heptanal by treatment with
benzylmagnesium chloride and from 1,2-epoxyoctane by treat-
ment with PhLi/CuCN (2:1).
rity?), 25.869 (CH2), 29.098 (CH2), 31.748 (CH2), 36.919 (CH2),
44.612 (CH), 72.644 (CH), 125.291 (CH), 127.705 (CH), 128.236
(CH), 129.002 (CH), 129.578 (CH), 134.039 (CH), 134.163 (small,
impurity?), 138.276 (C), 140.344 (C); GC/MS m/ z (tentative
assignment, relative intensity) 340 (M+, not visible), 188 (M+
-
HOSiMe2Ph, 28), 135 (PhMe2Si+, 52), 117 (Ph-CHdCH-CH2
,
+
60), 104 (Ph-CHdCH2+, 100), 91 (C7H7+, 20). GC analysis
(column S-3) [150 °C (0 min), 10 °C/min to 270 °C (8 min), C18H38
at 9.2 min] showed one major peak at 15.35 min (92%) and a
minor peak at 12.05 min (4.7%); under these conditions epoxy
silane 1 had a retention time of 10.2 min (none was visible).
To a solution of 0.10 g (0.39 mmol) of 1-phenyl-1-(phenyldi-
methylsilyl)-2-octanol (7) in 10 mL of CH2Cl2 was added 1.8 mL
(14.6 mmol) of BF3‚Et2O, and the resulting reaction mixture was
stirred at rt for 1 h. Then 25 mL of saturated NaHCO3 was
added, and the resulting mixture was stirred at rt for 10 min.
The layers were separated, the aqueous layer was extracted
twice with ether, and then the combined organic layers were
dried (MgSO4) and concentrated. Flash chromatography on 50
g of silica gel using petroleum ether/ether (9:1) gave 0.07 g (95%
yield) of (E)-1-phenyl-1-octene (9e).31
(Z)-1-P h en yld im eth ylsilyl-1,2-ep oxyocta n e (1). To a mix-
ture of 2.11 g (7.34 mmol) of m-CPBA and 1.02 g (7.19 mmol) of
Na2HPO4 in 40 mL of dichloromethane was added a solution of
1.24 g (5.03 mmol) of vinylsilane 15 in 2 mL of dichloromethane.
The resulting reaction mixture was stirred at rt for 26 h, and
then 15 mL of 20% aqueous NaHSO3 was added. The resulting
mixture was stirred for 1 h. Then the aqueous layer was
separated, 12 mL of 20% NaOH solution was added to the
organic layer, and the resulting mixture was stirred for 0.5 h.
Water was added, and the organic layer was washed with
saturated NaHCO3 followed by water, dried (MgSO4), and
concentrated. Chromatography on 75 g of Florisil using petro-
leum ether/ether (95:5) gave 1.21 g (92% yield) of the epoxy
silane 1 as a colorless liquid: 1H NMR δ 0.388 (3 H, s), 0.408 (3
H, s), 0.869 (3 H, t, J ) 7 Hz), 1.2-1.5 (10 H, m), 2.402 (1 H, d,
J ) 5 Hz), 3.120 (1 H, crude q), 7.375 (3 H, m), 7.563 (2 H, m);
13C NMR δ -3.289 (CH3), -2.791 (CH3), 13.967 (CH3), 22.495
(CH2), 26.908 (CH2), 29.079 (CH2), 31.373 (CH2), 31.685 (CH2),
50.139 (CH), 57.804 (CH), 127.884 (CH), 129.341 (CH), 133.831
(CH), 137.180 (C); GC/MS m/ z (tentative assignment, relative
Rea ction of Ep oxid e 1 w ith MeLi/Cu I: 2-(P h en yld im eth -
ylsilyl)-3-n on a n ol (4). To a mixture of 1.18 g (6.20 mmol) of
CuI in 10 mL of anhydrous ether at -45 °C was added 12.4 mL
(12.4 mmol) of methyllithium (1.0 M) dropwise. The resulting
reaction mixture was stirred for 1 h at -45 °C. Then a solution
of 0.40 g (1.52 mmol) of epoxy silane 1 in 4 mL of anhydrous
ether was added dropwise, and the resulting mixture was stirred
[2 h at -45 °C, 23 h (-45 °C f rt)]. Then 50 mL of saturated
NaHCO3 was poured into the reaction mixture, the layers were
separated, the aqueous layer was extracted three times with
ether, and then the combined organic layers were washed with
saturated NaHCO3 followed by water, dried (MgSO4), and
concentrated. Chromatography on 20 g of Florisil using petro-
leum ether/ether (95:5) gave 0.28 g (67% yield) of the â-hydroxy
silane 4 as a colorless liquid: 1H NMR (CH2Cl2 standard) δ 0.385
(3 H, s), 0.394 (3 H, s), 0.926 (3 H, t, J ) 7 Hz), 1.037 (3 H, d, J
) 7 Hz), 1.134 (1 H, m), 1.2-1.6 (11 H including OH, m), 3.798
(1 H, m), 7.4 (3 H, m), 7.6 (2 H, m); 13C NMR δ -3.890 (CH3),
-3.802 (CH3), 7.903 (CH3), 13.972 (CH3), 22.540 (CH2), 26.023
(CH), 26.211 (CH2), 29.219 (CH2), 31.777 (CH2), 36.270 (CH2),
72.847 (CH), 127.705 (CH), 128.799 (CH), 133.871 (CH), 136.831
(C); GC/MS m/ z (tentative assignment, relative intensity) 278
(M+, not visible), 260 (M+ - H2O, <1), 193 (M+ - Hex, 1), 152
(PhMe2SiOH+, 12), 137 (PhMeSiOH+, 100), 135 (PhMe2Si+, 100),
126 (Hex-CHdCH-Me+, 8), 115 (25), 105 (C6H5Si+, 15), 75 (30).
GC analysis (column S-3) [150 °C (1 min), 10 °C/min to 270 °C
(10 min), C18H38 at 11.0 min] showed one major peak at 12.48
min (100%).
intensity) 262 (M+, not visible), 247 (M+ - Me, 4), 233 (M+
-
Et, 2), 191 (M+ - Pent, 17), 137 (PhMeSiOH+, 36), 135 (PhMe2-
Si+, 100), 121 (PhMeSiH+, 10), 117 (10), 105 (10), 75 (10); calcd
mass for C15H23OSi (M+ - Me) 247.1518, HRMS (m/ z) 247.1517.
GC analysis (column S-3) [100 °C (1 min), 10 °C/min to 250 °C
(10 min), C18H38 at 15.2 min] showed one major peak at 15.3
min (98%); under these conditions vinylsilane 15 had a retention
time of 13.3 min (none was visible).
1-P h en yl-1-(p h en yld im eth ylsilyl)-2-octa n ol (7) a n d (E)-
1-P h en yl-1-octen e (9e). To a mixture of 0.63 g (3.31 mmol) of
CuI in 10 mL of anhydrous ether at -70 °C was added 8.3 mL
(6.6 mmol) of phenyllithium (0.8 M in ether) dropwise, and the
resulting reaction mixture was stirred at -55 °C for 1 h. Then
the mixture was recooled to -78 °C, a solution of 0.26 g (0.99
mmol) of epoxy silane 1 in 4 mL of ether was added, and the
resulting mixture was stirred for 0.5 h. Then 0.15 mL (1.22
mmol) of BF3‚Et2O in 30 mL of anhydrous ether was added
slowly (the temperature was kept below -70 °C), and the
resulting mixture was stirred for 1.5 h at -78 °C. Then a
mixture of 50 mL of saturated NH4Cl and 15 mL of ammonium
hydroxide was added, and the resulting mixture was stirred at
rt for 1 h. The layers were separated, the aqueous layer was
extracted twice with ether, and the combined organic layers were
dried (MgSO4) and concentrated to give 0.47 g of crude product.
Chromatography of a portion (0.24 g) of the crude product on
50 g of Florisil using petroleum ether/ether (9:1) gave 0.10 g (58%
yield39) of â-hydroxy silane 7 (Rf ) 0.3) as a colorless liquid: 1H
NMR δ 0.177 (3 H, s), 0.342 (3 H, s), 0.832 (3 H, crude t, J ) 7
Hz), 1.1-1.6 (16 H, including OH), 2.393 (1 H, d, J ) 7 Hz),
4.031 (1 H, m), 7.1-7.5 (10 H, m); 13C NMR δ -3.772 (CH3),
-2.379 (CH3), 13.984 (CH3), 22.531 (CH2), 22.630 (small, impu-
In a similar experiment, 0.26 g of epoxy silane 1 in 4 mL of
anhydrous ether was treated with MeLi/CuI (from 0.59 g of CuI,
10 mL of ether, and 4.4 mL of methyllithium) [2 h at -45 °C,
18 h (-45 °C f rt)] giving 0.26 g (93% crude yield) of 4 as a crude
product for comparison with compounds 3, 9e, 9z, and 10 as
discussed in the text.
Ack n ow led gm en t. Financial support from the Na-
tional Science Foundation (CHE-9505465 and CHE-
9007879) is gratefully acknowledged.
(35) Utimoto, K.; Kitai, M.; Nozaki, H. Tetrahedron Lett. 1975,
2825-2828. Zweifel, G.; Miller, J . A. Org. React. 1984, 32, 375-517.
(36) Ichinose, Y.; Nozaki, K.; Wakamatsu, K.; Oshima, K.; Utimoto,
K. Tetrahedron Lett. 1987, 28, 3709-3712. Nozaki, K.; Ichinose, Y.;
Wakamatsu, K.; Oshima, K.; Utimoto, K. Bull. Chem. Soc. J pn. 1990,
63, 2268-2272.
(37) Eisch, J . J .; Galle, J . E. J . Organomet. Chem. 1976, 121, C10-
C14.
(38) Siegel, S.; Boyer, W. M.; J ay, R. R. J . Am. Chem. Soc. 1951,
73, 3237-3240.
(39) Yield calculated as if purifying all of the crude product would
have resulted in the same percentage of pure product.
Su p p or tin g In for m a tion Ava ila ble: IR data for 1, 4, and
7, experimental details for preparation and/or characterization
of 3, 5, 8, 9z, 16, 17, 18, and 13C NMR spectra of 1, 3, 4, 5, 7,
8, 16, 17, and 18 (7 pages). This material is contained in
libraries on microfiche, immediately follows this article in the
microfilm version of the journal, and can be ordered from the
ACS; see any current masthead page for ordering information.
J O9613186