Stereoselective access to hydroxy oxetanes and tetrahydrooxepines through isomerization of oxiranyl ethers

Full text of DOI:10.1021/jo0005924

J . Org. Chem. 2001, 66, 3201-3205
3201
Sch em e 1
Ster eoselective Access to Hyd r oxy
Oxeta n es a n d Tetr a h yd r ooxep in es th r ou gh
Isom er iza tion of Oxir a n yl Eth er s
Alessandro Mordini,* Simona Bindi,
Antonella Capperucci, Daniele Nistri,
Gianna Reginato, and Michela Valacchi
Centro CNR Composti Eterociclici, Dipartimento di Chimica
Organica “U. Schiff”, via G. Capponi 9,
I-50121 Firenze, Italy
Sch em e 2
mordini@chimorg.unifi.it
Received April 18, 2000
We have shown in the past few years1-3 that allyl,
benzyl, and propargyl 2,3-epoxy ethers (1a , 1b, and 1c,
respectively, Scheme 1) can be regio- and stereoselectively
converted into 2-vinyl-, 2-phenyl-, or 2-alkynyl-3-(R-
hydroxyalkyl)oxetanes (2a , 2b, and 2c, respectively) by
treatment with the Schlosser’s base4 (butyllithium/potas-
sium tert-butoxide) or other superbasic mixtures5,6 such
as lithium diisopropylamide/potassium tert-butoxide
(LIDAKOR7).
Sch em e 3
The formation of oxetanes (a) is favored over the
alternative five-membered ring cyclization (b) for the
benzyl and propargyl oxiranyl ethers 1b and 1c and over
the 5- (b), 6- (c) and 7-membered (d) ring formation for
the allyl oxiranyl ethers 1a (Scheme 2).8
Sch em e 4
Monosubstituted oxiranes derived from allyl vinyl
carbinols (1, R ) H, R′ ) alkyl) are a more intriguing
case because the absence of any substituent on one ring
carbon may favor to a certain extent the formation of a
5-membered ring (b) with benzyl- or propargyl-substi-
tuted substrates (1b and 1c, R ) H, R′ ) alkyl) and a 5-
(b) or 7-membered ring (d) with allyl derivatives (1a , R
) H, R′ ) alkyl).
Previous reports on this matter9,10 have shown indeed
that allyl glycidyl ether 3 is converted into a mixture of
trans-3-(hydroxymethyl)-2-vinyloxetane 4 and 3-hydroxy-
tetrahydrooxepine 5 upon treatment with sec-butyl-
lithium in THF/HMPT at -70 °C (Scheme 3).9 When
alkyl substituents are present on different positions of
the allyl glycidyl ether, similar reaction conditions10
afford usually the tetrahydrooxepine derivative as the
major product albeit in less than 50% yield.
via epoxidation of the corresponding allylic alcohols
(Scheme 4, Table 1).
Compounds 6g-j have been clearly converted into
2-phenyl- and 2-alkynyl-substituted oxetanes 7g-j in
good yields by treatment with the superbase LIDAKOR.
The relative stereochemistry of substituents in positions
3 and 4 of the oxetane ring is due to the configuration of
the starting epoxy ether, while the cis or trans relation-
ship between substituents in position 2 and 3 arises
during the cyclization step. The selectivity is the one
expected according to our previous findings,3 the trans-
isomers being always preferred. Compounds 7h and 7j
are particularly interesting in view of an application to
the synthesis of the oxetane containing nucleoside oxe-
tanocin, which has received a great deal of attention in
recent years11-17 due to its potent activity as an antiviral,
antibiotic, and antitumor16 agent.
Owing to our previous experience, we have decided to
investigate the mixed metal base promoted isomerization
of terminal oxiranyl ethers of type 6, readily prepared
(1) Mordini, A.; Valacchi, M.; Nardi, C.; Bindi, S.; Poli, G.; Reginato,
G. J . Org. Chem. 1997, 62, 8557.
(2) Mordini, A.; Bindi, S.; Pecchi, S.; Capperucci, A.; Degl’Innocenti,
A.; Reginato, G. J . Org. Chem. 1996, 61, 4466.
(3) Mordini, A.; Bindi, S.; Pecchi, S.; Degl’Innocenti, A.; Reginato,
G.; Serci, A. J . Org. Chem. 1996, 61, 4374.
(4) Schlosser, M. J . Organomet. Chem. 1967, 8, 9.
(5) Mordini, A. In Advances in Carbanion Chemistry; Snieckus, V.,
Ed.; J AI Press: Greenwich CT, 1992; Vol. 1, p 1.
(6) Mordini, A. In Comprehensive Organometallic Chemistry II; M.
A. v., Ed.; Pergamon Press: Oxford, 1995; Vol. 11, p 93.
(7) Margot, C.; Schlosser, M. Tetrahedron Lett. 1985, 26, 1035.
(8) Still, W. C. Tetrahedron Lett. 1976, 25, 2115.
(9) Ichikawa, Y.; Niitsuma, S.; Kuniki, K.; Takita, T. J . Chem. Soc.,
Chem. Commun. 1988, 625.
(11) Hambalek, R.; J ust, G. Tetrahedron Lett. 1990, 31, 5445.
(12) Niitsuma, S.; Ichikawa, Y.; Kato, K.; Takita, T. Tetrahedron
Lett. 1987, 28, 4713.
(13) Niitsuma, S.; Ichikawa, Y.; Kato, K.; Takita, T. Tetrahedron
Lett. 1987, 28, 3967.
(14) Nishiyama, S.; Yamamura, S.; Kato, K.; Takita, T. Tetrahedron
Lett. 1988, 29, 4743.
(15) Nishiyama, S.; Yamamura, S.; Kato, K.; Takita, T. Tetrahedron
Lett. 1988, 29, 4739.
(10) Bird, C. W.; Hormozi, N. Tetrahedron Lett. 1990, 31, 3501.
10.1021/jo0005924 CCC: $20.00 © 2001 American Chemical Society
Published on Web 04/11/2001

3202 J . Org. Chem., Vol. 66, No. 9, 2001
Notes
Ta ble 1. Regio- a n d Ster eoselective Ou tcom e in th e
Cycliza tion of Ep oxy Eth er s 6
Sch em e 5
7 (cis:trans):
8 (cis:trans)
R
Y
yielda (%)
6d
6e
6f
6g
6h
6i
H
C5H11
CH2OSiMe2tBu
C5H11
CH2OSiMe2tBu
C5H11
CH2dCH
CH2dCH
CH2dCH
C6H5
C6H5
CHtC
CHtC
2:98 (98:2)
2:98 (98:2)
2:98 (98:2)
98 (5:95):2
98 (2:98):2
98 (20:80):2
98 (15:85):2
90 (45)
94 (65)
68 (53)
70 (53)
89 (55)
95 (55)
83 (50)
6j
CH2OSiMe2tBu
a
Calculated by 1H NMR analysis; the yields of isolated products
are given in parentheses.
Allyl oxiranyl ethers 6d -f have shown a remarkably
selective behavior in their treatment with the Schlosser’s
base. Only the cyclization to 7-membered rings is fol-
lowed, leading to the cis-tetrahydrooxepines 8d -f in
reasonable yields. It is worth noting that previous similar
experiments9,10 conducted with organolithium reagents
have led to mixtures of 7- and 4-membered-ring products.
It is reasonable to assume that the preference for oxepine
formation found in this case is ascribed to the higher
preference of the allylpotassium species compared with
the lithium analogues, to react at their terminal posi-
tion.18
Exp er im en ta l Section
Gen er a l P r oced u r es. Air- and moisture-sensitive com-
pounds were stored in Schlenk tubes or in Schlenk burets. They
were protected by and handled under an atmosphere of 99.99%
pure nitrogen. Ethereal extracts were dried with sodium sulfate.
The temperature of dry ice-ethanol baths is consistently
indicated as -78 °C, that of ice baths as 0 °C, and “room
temperature” as 25 °C. Purifications by flash column chroma-
tography23 were performed using glass columns (10-50 mm
wide); silica gel 230-400 mesh was chosen as stationary phase
(15 cm high), with an elution rate of 5 cm/min. Nuclear magnetic
resonance spectra of hydrogen nuclei were recorded at 200 or
500 MHz. Chemical shifts were determined relative to the
residual solvent peak (CHCl3: 7.26 ppm). Coupling constants (J )
are measured in Hz. Coupling patterns are described by ab-
breviations: s (singlet), d (doublet), t (triplet), q (quartet), quint
(quintet), dd (doublet of a doublet), m (multiplet), bs (broad
singlet). Nuclear magnetic resonance spectra of carbon-13 nuclei
were recorded at 50.3 or 75.5 MHz. Chemical shifts were
determined relative to the residual solvent peak (CHCl3: 77.0
The tetrahydrooxepines 8d -f are all obtained as pure
cis isomers which are the ones expected for a carbanionic
attack on an erythro oxirane, without any loss of stereo-
chemical integrity. Interestingly, the oxepines are not
configurationally stable and undergo an isomerization to
a 50:50 cis:trans mixture in CDCl3.
To assess the steric and/or electronic influence of a
trialkylsilyl group on the cyclization process, we have
decided to investigate the isomerization of trialkysilyl
substituted oxiranes 9k ,l, which are readily prepared
from the commercially available trialkylsilyl acetylene
via lithiation and reaction with hexanal followed by
reduction of the triple bond, Sharpless epoxidation,19 and
allylation of the epoxy alcohol (Scheme 5).
ppm). Mass spectra were obtained at
potential.
a 70 eV ionization
Ma ter ia ls. Starting materials were commercially available
unless otherwise stated. All commercial reagents were used
without further purification except diisopropylamine, which was
distilled over calcium hydride. Anhydrous tetrahydrofuran was
distilled from sodium diphenylketyl. Dimethylformamide was
distilled over calcium hydride and then stored over 4 Å molecular
sieves. Methylene chloride was dried over calcium chloride and
stored over 4 Å molecular sieves. Petroleum ether, unless
specified, was the 40-70 °C boiling fraction.
1. P r ep a r a tion of Oxir a n yl Eth er s 6e,g,i. 1-Octen-3-ol
(1.92 g, 15 mmol) and vanadyl acetylacetonate (0.07 g, 0.25
mmol) were dissolved in CH2Cl2 (45 mL) under N2 and cooled
to 0 °C. Then t-BuOOH (5.4 mL of 5.5 M solution in decane,
dried over molecular sieves, 30 mmol) was slowly added. The
mixture was stirred at room temperature for 16 h, washed with
saturated aqueous Na2S2O3 and brine, and dried. After evapora-
tion of the solvent, the residue was purified by column chroma-
tography (petroleum ether/ethyl acetate, 2:1), affording 1.41 g
(65%) of a 80:20 mixture of erythro- and threo-1,2-epoxyoctan-
3-ol.24 Erythro: 1H NMR (CDCl3, 200 MHz) (erythro): δ 3.9-
3.8 (1H, m); 3.02 (1H, ddd, J ) 5.8, 3.8, 2.8 Hz); 2.81 (1H, dd, J
) 4.8, 2.8 Hz); 2.73 (1H, dd, J ) 4.8, 3.8 Hz); 2.0-1.7 (1H, bs);
1.6-1.2 (8H, m); 0.89 (3H, t, J ) 6.6 Hz). The epoxy alcohol (1.41
g, 9.7 mmol) was dissolved in DMF (10 mL), and after cooling
to -5 °C, a suspension of NaH (0.40 g, 10 mmol) in DMF (10
mL) was added during 30 min. After an additional 30 min, a
solution of the suitable halide (10 mmol; e: CH2dCHCH2Br, g:
C6H5CH2Br, i: CHtCCH2Br) in DMF (10 mL) was added, and
the mixture warmed to 25 °C, and then stirred for 15 h, before
The trimethylsilyl-substituted compound 9k gives,
upon treatment with Schlosser’s base, the tetrahydro-
oxepine 11k as the only product while the more hindered
triisopropyl derivative 9l leads to a mixture of 4-mem-
bered and 7-membered ring products in a 72:28 ratio.
Thus, the trialkylsilyl substituent exerts both steric and
electronic effects on the mode of cyclization (alkyl-
substituted oxiranes give only oxetanes in the same
reaction conditions).
In conclusion, we have demonstrated that the super-
base-promoted isomerization of oxiranyl ethers is a useful
process selectively leading to trisubstituted oxetanes20,21
or to disubstituted tetrahydrooxepines,22 both classes of
compounds being of high synthetic potential.
(16) Norbeck, D. W.; Kramer, J . B. J . Am. Chem. Soc. 1988, 110,
7217.
(17) Wilson, F. X.; Fleet, G. W. J .; Vogt, K.; Wang, Y.; Witty, D. R.;
Choi, S.; Storer, R.; Myers, P. L.; Wallis, C. J . Tetrahedron Lett. 1990,
31, 6931.
(18) Schlosser, M.; Desponds, O.; Lehmann, R.; Moret, E.; Rauch-
schwalbe, G. Tetrahedron 1993, 49, 10175.
(19) Okamoto, S.; Shimazaki, T.; Kobayashi, Y.; Sato, F. Tetrahedron
Lett. 1987, 28, 2033.
(20) Linderman, R. J . In Comprehensive Heterocyclic Chemistry II;
Padwa, A., Ed.; Pergamon: Oxford, 1996; Vol. 1B, pp 755-771.
(21) Linderman, R. J . In Comprehensive Heterocyclic Chemistry II;
Padwa, A., Ed.; Pergamon: Oxford, 1996; Vol. 1B, pp 721-753.
(22) Hoberg, J . O. Tetrahedron 1988, 54, 12631.
(23) Still, W. C.; Kahn, M.; Mitra, A. J . Org. Chem. 1978, 43, 2923.
(24) Kitano, Y.; Matsumoto, T.; Sato, F. Tetrahedron 1988, 44, 4073.

Notes
J . Org. Chem., Vol. 66, No. 9, 2001 3203
it was treated with H2O (7 mL) and extracted with ether. The
organic phase was washed with H2O and saturated NaCl and
dried. After evaporation of the solvent, the oxiranyl ethers
(6e,g,i) were purified by chromatography; only the erythro
isomer was fully characterized and further used.
L-(+)-diisopropyltartrate (5.34 g, 23 mmol) were mixed under
N2 and cooled to -23 °C. 1-[(tert-Butyldimethylsilyl)oxy]-3-buten-
2-ol (3.84 g, 19 mmol) was then added and the mixture
maintained at -23 °C for 30 min before t-BuOOH (2.72 mL of a
5.5 M solution in decane, dried over molecular sieves, 15 mmol)
was slowly added. After 3 days, the cold reaction mixture was
poured into a precooled (-20 °C) solution consisting of 130 mL
of reagent-grade acetone containing 5.5 mL of water. The
resulting mixture was stirred and allowed to warm to 25 °C.
Stirring was continued until the formation of an opaque solution
that was filtered. After evaporation of the solvent, the residue
was diluted with 130 mL of ether, and then, after cooling to 0
°C, 52 mL of 1 N sodium hydroxide solution was added. This
two-phase mixture was stirred at 0 °C for 0.5 h, and then the
ether phase was washed with brine and dried (Na2SO4). After
evaporation of the solvent, 2.52 g of a 60:40 mixture of (2R)-1-
[(tert-butyldimethylsilyl)oxy]-3-buten-2-ol and anti-(2S,3R)-1-
[(tert-butyldimethylsilyl)oxy]-3,4-epoxy-2-butanol was obtained,
and the compounds were separated by chromatography (petro-
leum ether/ethyl acetate 4:1) to afford 1.14 g of pure R-allylic
alcohol and 0.70 g (42%) of pure epoxy alcohol. 1H NMR (CDCl3,
200 MHz) δ: 3.76 (2H, AB system); 3.55 (1H, app q, J ) 5.0
Hz); 3.04 (1H, ddd, J ) 5.4, 4.0, 2.6 Hz); 2.81 (1H, dd, J ) 5.2,
4.0 Hz); 2.76 (1H, dd, J ) 5.2, 2.6 Hz); 2.44 (1H, bs); 0.91 (9H,
s); 0.09 (6H, s).
3-(2-P r op en oxy)-1,2-ep oxyocta n e 6e. Purification: eluent
petroleum ether/ethyl acetate 15:1; yield 56%; erythro:threo 78:
22. 1H NMR (CDCl3, 200 MHz): erythro: 5.90 (1H, ddt, J ) 17.2,
10.2, 5.6 Hz); 5.25 (1H, app dq, J ) 17.2, 1.8 Hz); 5.16 (1H, dq,
J ) 10.2, 1.8 Hz); 4.04 (2H, AB system); 3.2-3.1 (1H, m); 2.89
(1H, ddd, J ) 5.4, 4.0, 2.6 Hz); 2.79 (1H, dd, J ) 5.4, 4.0 Hz);
2.72 (1H, dd, J ) 5.4, 2.6 Hz); 1.6-1.2 (8H, m); 0.89 (3H, t, J )
6.6 Hz). 13C NMR (CDCl3, 75.45 MHz) δ: 135.1; 116.8; 78.1; 71.2;
53.4; 45.6; 32.8; 31.8; 24.8; 22.5; 14.0. MS (m/z): 183 (0.01, M+
- 1); 141 (37, M+ - C3H7); 99 (57); 81 (49); 71 (82); 69 (28); 68
(21); 67 (33); 57 (71); 55 (100). Anal. Calcd for C11H20O2: C, 71.70;
H, 10.94. Found: C, 71.42; H, 10.77.
3-Ben zyloxy-1,2-ep oxyocta n e 6g.25 Purification: eluent
petroleum ether/ ethyl acetate 15:1; yield 55%; erythro:threo 80:
1
20. H NMR (CDCl3, 200 MHz): erythro: 7.4-7.2 (5H, m); 4.58
(2H, AB system); 3.3-3.2 (1H, m); 2.93 (1H, ddd, J ) 5.6, 3.8,
2.6); 2.78 (1H, dd, J ) 5.4, 3.8); 2.72 (1H, dd, J ) 5.4, 2.6); 1.7-
1.2 (8H, m); 0.89 (3H, t, J ) 7.0). 13C NMR (CDCl3, 75.45 MHz)
δ: 138.6; 128.4; 127.7; 127.6; 78.1; 72.3; 53.6; 45.6; 32.8; 31.8;
24.8; 22.5; 14.0. MS (m/z): 234 (0.75, M+); 127 (2.2, M+
-
OCH2C6H5); 107 (61); 91 (100, C7H7+); 65 (26); 43 (25); 41 (27).
3-(2-P r op yn oxy)-1,2-ep oxyocta n e 6i.26 Purification: eluent
petroleum ether/ ethyl acetate 10:1; yield: 54%. erythro:threo
80:20. 1H NMR (CDCl3, 200 MHz) (erythro): 4.22 (2H, AB of
ABX); 3.4-3.3 (1H, m); 2.90 (1H, ddd, J ) 5.0, 3.2, 2.6); 2.8-2.7
(2H, m); 2.41 (1H, app t, J ) 2.6); 1.6-1.2 (8H, m); 0.89 (3H, t,
J ) 6.6). 13C NMR (CDCl3, 75.45 MHz) δ: 80.0; 77.4; 74.2; 57.3;
53.1; 45.4; 32.6; 31.8; 24.6; 22.5; 14.0. MS (m/z): 139 (100, M+
- C3H7); 111 (69, M+ - C5H11); 99 (40); 83 (38); 82 (28); 81 (58);
71 (72); 69 (43); 68 (32); 67 (56); 57 (44); 56 (34); 55 (100); 54
(68), 53 (98).
2. P r ep a r a tion of Oxir a n yl Eth er s 6f,h ,j. 3-Bu ten e-1,2-
d iol.27 A mixture of 2-butene-1,4-diol (25 g, 0.28 mol), water (10
mL), concentrated sulfuric acid (0.14 mL), and mercuric sulfate
(0.10 g) was heated under reflux. After 1.5 h, the reaction
mixture was cooled to 0 °C, neutralized with 10% sodium
hydroxide to pH 7, and then distilled. The first fraction, distilled
between 50 and 55 °C/15 mmHg, contained water, the second
fraction collected between 110 and 115 °C/15 mmHg, contained
3-buten-1,2-diol (13 g, 52%) as a colorless liquid, and the third
fraction, collected between 125 and 130 °C/15 mmHg, had traces
of unreacted starting material. 3-Butene-1,2-diol. 1H NMR
(CDCl3, 200 MHz) δ: 5.86 (1H, ddd, J ) 17.6, 10.6, 5.8); 5.37
(1H, app dt, J ) 17.6, 1.4); 5.24 (1H, app dt, J ) 10.6, 1.6); 4.3-
4.2 (1H, m); 3.69 (1H, dd, J ) 11.4, 3.6); 3.51 (1H, dd, J ) 11.4,
7.2), 2.13 (2H, s).
1-[(ter t-Bu t yld im et h ylsilyl)oxy]-3-b u t en -2-ol.28 The 3-
butene-1,2-diol (2.64 g, 30 mmol) was dissolved in THF (48 mL),
and after the solution was cooled to -78 °C, BuLi (18.7 mL of
1.6 M solution in hexane, 30 mmol) was slowly added. After an
additional 15 min, tert-butyldimethylsilyl chloride (4.53 g, 30
mmol) was added, and the mixture was warmed to 25 °C and
then stirred for 15 h. After evaporation of the solvent, the residue
was purified by chromatography, eluent petroleum ether/ethyl
acetate 7:1 affording 3.84 g (63%) of monoprotected diol. 1H NMR
(CDCl3, 200 MHz) δ: 5.81 (1H, ddd, J ) 17.6, 10.6, 5.8); 5.34
(1H, app dt, J ) 17.4, 1.4); 5.19 (1H, app dt, J ) 10.6, 1.4); 4.2-
4.1 (1H, m); 3.66 (1H, dd, J ) 10.0, 3.6); 3.44 (1H, dd, J ) 10.0,
7.8); 2.3-2.1 (1H, bs); 0.90 (9H, s); 0.08 (6H, s).
P r ep a r a tion of Oxir a n yl Eth er s. Gen er a l P r oced u r e.
Meth od A. NaH (0.08 g, 3.2 mmol) suspended in THF (5 mL)
was added to a precooled (-5 °C) solution of anti-(2S,3R)-1-[(tert-
butyldimethylsilyl)oxy]-3,4-epoxy-2-butanol (0.70 g, 3.2 mmol)
in THF (5 mL). After 30 min at -5 °C, cat. Bu4NI and then the
suitable halide (3.2 mmol) were added, and the mixture was
stirred for 3 h at 25 °C before it was treated with water-ice
and extracted with ether. The organic phase was washed with
brine and dried.
Meth od B. A suspension of epoxide (0.70 g, 3.2 mmol),
benzyltriethylammonium chloride (0.51 g, 2.24 mmol), and the
suitable halide (7.0 mmol) in benzene (7 mL) and 70% aq NaOH
(7 mL) was stirred vigorously at 25 °C for 14 h. The mixture
was extracted with ether, and the organic phase was washed
with water and brine and dried.
a n t i-(2S ,3R )-2-(2-P r op e n oxy)-1-[(t er t -b u t yld im e t h yl-
silyl)oxy]-3,4-ep oxybu ta n e 6f. Compound 6f was prepared
according to procedure A, giving 0.69 g of crude which was then
purified by column chromatography (petroleum ether/ethyl
acetate 7:1), affording 0.58 g of 6f (70%) as an anti:syn (70:30)
mixture. An ti: 1H NMR (CDCl3, 200 MHz) δ: 5.90 (1H, ddt,
J ) 17.2, 10.2, 5.6 Hz); 5.58 (1H, app dq, J ) 17.2, 1.8 Hz); 5.37
(1H, app dq, J ) 10.2, 1.8 Hz); 4.10 (2H, AB system); 3.75 (2H,
app d, J ) 5.6 Hz); 3.35 (1H, m); 3.1-3.0 (1H, m); 2.77 (2H, app
d, J ) 3.4 Hz); 0.90 (9H, s); 0.07 (6H, s). Anal. Calcd for C13H26O3-
Si: C, 60.42; H, 10.14. Found: C, 60.32; H, 10.27. Syn : 1H NMR
(CDCl3, 200 MHz) δ: 6.0-5.8 (1H, m); 5.4-5.1 (2H, m); 4.02
(2H, AB system); 3.9-3.7 (1H, m); 3.52 (1H,app s); 3.49 (1H,
AB system); 3.1-3.0 (1H, m); 2.7-2.6 (2H, m); 0.87 (9H, s); 0.07
(6H, s). Only the anti isomer was further used.
a n ti-(2S,3R)-2-Ben zyloxy-1-[(ter t-b u t yld im et h ylsilyl)-
oxy]-3,4-ep oxybu ta n e 6h . Compound 6h was prepared accord-
ing to procedure A, giving 0.80 g of crude which was then
purified by column chromatography (petroleum ether/ethyl
acetate 10:1), affording 0.59 g of 6h (60%) as an anti:syn (71:
1
29) mixture. An ti: H NMR (CDCl3, 200 MHz) δ: 7.4-7.2 (5H,
m); 4.65 (2H, AB system); 3.78 (2H, app d, J ) 5.0 Hz); 3.41
(1H, app q, J ) 4.9 Hz); 3.08 (1H, ddd, J ) 6.6, 3.6, 2.4 Hz);
2.8-2.7 (2H, m); 0.90 (9H, s); 0.06 (6H, s). Anal. Calcd for
C
17H28O3Si: C, 66.19; H, 9.15. Found: C, 66.32; H, 9.27. Syn :
a n ti-(2S,3R)-1-[(ter t-bu tyld im eth ylsilyl)oxy]-3,4-ep oxy-
1H NMR (CDCl3, 200 MHz) δ: 7.4-7.2 (5H, m); 4.57 (2H, AB
system); 3.9-3.8 (1H, m); 3.54 (2H, app d, J ) 5.0 Hz); 3.1-3.0
(1H, m); 2.8-2.7 (2H, m); 0.87 (9H, m); 0.05 (6H, m).
2-bu ta n ol.29 Ti(i-OPr)4 (5.40 g, 19 mmol), CH2Cl2 (65 mL), and
Only the anti isomer was further used.
(25) Sato, F.; Kobayashi, Y.; Takahashi, O.; Osamu, C.; Tsunehisa,
T.; Takeda, Y.; Kusakabe, M. J . Chem. Soc., Chem. Commun. 1985,
1636.
(26) Maiti, G.; Roy, S. C. J . Chem. Soc., Perkin Trans. 1 1996, 403.
(27) Rama Rao, A. V.; Gurjar, M. K.; Bose, D. S.; Devi, R. R. J . Org.
Chem. 1991, 56, 1320.
(28) Crilley, M. M. L.; Golding, B. T.; Pierpoint, C. J . Chem. Soc.,
Perkin Trans. 1 1988, 2061.
(29) Gurjar, M. K.; Devi, N. R. Tetrahedron: Asymmetry 1994, 5,
755.
a n t i-(2S ,3R )-2-(2-P r op yn oxy)-1-[(t er t -b u t yld im e t h yl-
silyl)oxy]-3,4-ep oxybu ta n e 6j. Compound 6j was prepared
according to procedure B, giving 0.17 g of crude which was then
purified by column chromatography (petroleum ether/ethyl
acetate 7:1), affording 0.15 g of 6j (70%) as an anti:syn (71:29)
mixture. An ti: 1H NMR (CDCl3, 200 MHz) δ: 4.29 (2H, d, J )
2.2 Hz); 3.8-3.7 (2H, m); 3.52 (1H, m); 3.05 (1H, ddd, J ) 6.6,
5.2, 3.4 Hz); 2.80 (1H, app d, J ) 2.8 Hz); 2.71 (1H, app d, J )

3204 J . Org. Chem., Vol. 66, No. 9, 2001
Notes
3.4 Hz); 2.41 (1H, app t, J ) 2.2 Hz); 0.90 (9H, s); 0.08 (6H, s).
Anal. Calcd for C13H24O3Si: C, 60.89; H, 9.43. Found: C, 60.72;
H, 9.37. Syn : 1H NMR (CDCl3, 200 MHz) δ: 4.19 (2H, d, J )
2.6 Hz); 3.8-3.7 (1H, m); 3.6-3.5 (2H, m); 3.1-3.0 (1H, m); 2.8-
2.7 (2H, m); 2.43 (1H, app t, J ) 2.6 Hz); 0.88 (9H, s); 0.05 (6H,
s). Only the anti isomer was further used.
3. Isom er iza tion of Oxir a n es. Rea ction w ith LIDAKOR
or LICKOR. Hexane was stripped off from a solution of BuLi
(0.74 mL of a 1.5 M solution, 1.10 mmol for LIDAKOR; 0.37 mL
of a 1.5 M solution, 0.55 mmol for LICKOR), and precooled THF
(1.0 mL) was added at -78 °C under N2, followed by diisopropyl-
amine (112 mg, 1.10 mmol for LIDAKOR) and potassium tert-
butoxide (124 mg, 1.10 mmol for LIDAKOR; 62 mg, 0.55 mmol
for LICKOR). The mixture was stirred at -78 °C for 45 min,
after which time the oxirane (0.50 mmol) was added and allowed
to react for 15 h at -50 °C; the reaction was then quenched with
H2O (2.0 mL) and extracted twice with Et2O, after warming to
25 °C. The organic layers were combined, washed with brine,
and dried. After evaporation of the solvent the residue was
purified.
tate 3:1), giving 84 mg (55%) of pure trans,trans-7h . 1H NMR
(CDCl3, 200 MHz) δ: 7.5-7.2 (5H, m); 5.46 (1H, d, J ) 7.0);
4.7-4.6 (1H, m); 3.9-3.8 (4H, m); 2.97 (1H, quint, J ) 7.0); 1.8-
1.7 (1H, bs); 0.90 (9H, s); 0.09 (6H, s).13C NMR (CDCl3, 75.45
MHz) δ: 142.2; 128.4; 127.9; 125.6; 81.5; 80.6; 65.6; 62.6; 48.7;
25.9; 18.3; -5.5. MS (m/z): 283 (2); 145 (18); 129 (12); 117 (100).
Anal. Calcd for C17H28O3Si: C, 66.19; H, 9.15. Found: C, 65.84;
H, 8.99.
(2,3-tr a n s-3,4-tr a n s)-2-Eth yn yl-3-(h ydr oxym eth yl)-4-pen -
tyloxeta n e (tr a n s,tr a n s-7i). The procedure with 2 equiv of
LIDAKOR was used on epoxide 6i, obtaining 87 mg (95%) of a
20:80 mixture of cis,trans-7i and trans,trans-7i, which was then
purified by column chromatography (petroleum ether/ethyl
acetate 3:1), giving 50 mg (55%) of pure trans,trans-7i. 1H NMR
(CDCl3, 200 MHz) δ: 5.00 (1H, dd, J ) 6.6, 1.8 Hz); 4.47 (1H,
app q, J ) 6.4 Hz); 3.83 (2H, d, J ) 5.8 Hz); 2.9-2.7 (1H, m);
2.73 (1H, d, J ) 1.8 Hz); 2.0-1.2 (9H, m); 0.89 (3H, t, J ) 6.2
Hz).13C NMR (CDCl3, 75.45 MHz) δ: 83.1; 82.0; 76.3; 67.6; 62.0;
50.0; 37.2; 31.5; 23.6; 22.5; 14.0. MS (m/z): 182 (0.2, M+); 151
(4, M+ - CH2OH); 95 (20); 83 (45); 82 (71); 81 (83); 72 (22); 71
(38); 68 (36); 67 (31); 65 (20); 57 (44); 55 (100); 54 (92); 53 (91).
Anal. Calcd for C11H18O2: C, 72.49; H, 9.95. Found: C, 72.11;
H, 9.76.
(2,3-tr a n s-3,4-tr a n s)-2-Eth yn yl-3-(h ydr oxym eth yl)-4-(ter t-
bu tyld im eth ylsilyloxym eth yl)oxeta n e (tr a n s,tr a n s-7j). The
procedure with 2 equiv of LIDAKOR was used on epoxide 6j,
obtaining 106 mg (83%) of a 15:85 mixture of cis,trans-7j and
7j which was then purified by column cromatography (petroleum
ether/ethyl acetate 3:1), giving 64 mg (50%) of pure trans,trans-
7j. 1H NMR (CDCl3, 200 MHz) δ: 5.03 (1H, dd, J ) 7.0, 2.2 Hz);
4.6-4.4 (1H, m); 3.83 (2H, d, J ) 6.2 Hz); 3.79 (2H, d, J ) 5.0);
3.07 (1H, app quint, J ) 6.2 Hz); 2.72 (1H, d, J ) 2.2 Hz); 2.0-
1.7 (1H, bs); 0.91 (9H, s); 0.10 (3H, s); 0.08 (3H, s). Anal. Calcd
for C13H24O3Si: C, 60.89; H, 9.43. Found: C, 61.05; H, 9.60.
(2,3-tr a n s-3,4-tr a n s)-2-Eth yn yl-3-(h yd r oxym eth yl)-4-h y-
d r oxym eth yl-oxeta n e. 13C NMR (CDCl3, 75.45 MHz) δ: 81.6;
77.3; 68.0; 64.0; 61.4; 44.8; 40.3.
P r ep a r a tion of Silyl Oxir a n yl Eth er s. 1-Tr ia lk ylsilyloct-
1-yn -3-ol.24 Trialkylsilyl acetylene (10 mmol) was added drop-
wise to a 1.5 M solution of BuLi in hexane (10 mmol) at 0 °C.
The resulting solution was stirred for 1 h at 25 °C. Then hexanal
(1.00 g, 10 mmol) was added dropwise at -30 °C. The mixture
was warmed to 25 °C and stirred for 1.5 h, then was poured
into ice-cooled saturated NH4Cl and extracted with hexane, and
the combined organic layers were dried (Na2SO4) to afford the
crude (1.59 g, 80% for alkyl ) CH3 and 1.98 g, 70% for alkyl )
[(CH3)2CH]3).
3-Hyd r oxy-2,3,4,5-t et r a h yd r oxep in e 8d .9 The procedure
with LICKOR was used on epoxide 6d , obtaining 51 mg (90%)
of a crude product which was then purified by column chroma-
tography (petroleum ether/ethyl acetate 3:2), giving 26 mg (45%)
of 8d . 1H NMR (CDCl3, 200 MHz) δ: 6.30 (1H, dt, J 6.2, 2.1);
4.79 (1 H, app. q, J ) 6.4); 4.02 (1H, dd, J ) 11.7, 2.5); 3.9-3.8
(1H, m); 3.87 (1H, dd, J ) 11.7, 4.2); 2.6-2.4 (1H, m); 2.3-2.1
(1H, m); 2.0-1.8 (2H, m); 1.8 (1H, m).
cis-2-P en tyl-3-h yd r oxy-2,3,4,5-tetr a h yd r oxep in e 8e. The
procedure with LICKOR was used on epoxide 8e, obtaining 87
mg (94%) of a crude product which was then purified by column
chromatography (petroleum ether/ethyl acetate 5:1), giving 60
mg (65%) of cis-8e. 1H NMR (CDCl3, 200 MHz) δ: 6.30 (1H, ddd,
J ) 6.4, 2.2, 0.8 Hz); 4.75 (1H, app tdd, J ) 7.0, 3.2, 0.8 Hz);
3.9-3.8 (1H, m); 3.72 (1H, app td, J ) 8.4, 2.6); 2.5-2.3 (1H,
m); 2.3-2.0 (1H, m); 2.0-1.8 (1H, m); 1.8-1.2 (10H, m); 0.89
(3H, t, J ) 6.2 Hz). 13C NMR (CDCl3, 75.45 MHz) δ: 148.0; 110.0;
85.5; 73.6; 33.9; 33.0; 31.7; 25.5; 22.6; 20.1; 14.0. MS (m/z %):
184 (14, M+); 166 (6, M+ - H2O); 113 (19, M+ - C5H11), 109
(21); 99 (25); 95 (45); 85 (25); 84 (71); 83 (73); 82 (33); 81 (78); 79
(21); 71 (69); 70 (56); 69 (38); 68 (30); 67 (46); 59 (20); 58 (46); 57
(100); 56 (25); 55 (80). Anal. Calcd for C11H20O2: C, 71.70; H,
10.94. Found: C, 71.52; H, 10.87.
cis-2-(t er t -Bu t yld im e t h ylsilyl)oxym e t h yl-3-h yd r oxy-
2,3,4,5-tetr a h yd r oxep in e 8f. The procedure with LICKOR was
used on epoxide 6f, obtaining 88 mg (68%) of a 98:2 mixture of
cis-8f and trans-8f, which was then purified by Florisil (petro-
leum ether/ethyl acetate 7:1), giving 68 mg (53%) of cis-8f. 1H
NMR (CDCl3, 200 MHz) δ: 6.34 (1H, ddd, J ) 6.4, 1.8, 1.0 Hz);
4.78 (1H, app tdd, J ) 6.6, 3.2, 1.04 Hz); 4.0-3.4 (4H, m); 2.6-
2.3 (1H, m); 2.2-2.0 (1H, m); 2.0-1.8 (1H, m); 1.8-1.6 (1H, m);
1.0 (1H, m); 0.88 (9H, s); 0.058 (3H, s); 0.054 (3H, s). 13C NMR
(CDCl3, 75.45 MHz) δ: 147.8; 110.5; 86.5; 70.5; 63.7; 34.4; 25.7;
20.0; 17.8; -4.3; -4.9. MS (m/z): 201 (3, M+ - C4H9); 145 (13,
CH2OSi[(CH3)2C(CH3)3); 101 (13, OSiC(CH3)3); 81 (25); 75 (100);
73 (22); 57 (30). Anal. Calcd for C13H26O3Si: C, 60.42; H, 10.14.
Found: C, 60.42; H, 10.37.
(2,3-tr a n s-3,4-tr a n s)-2-P h en yl-3-(1-h yd r oxym et h yl)-4-
p en tyloxeta n e (tr a n s,tr a n s-7g). The procedure with LIDA-
KOR was used on epoxide 6g, obtaining 82 mg (70%) of a 5:95
mixture of cis,trans-7g and trans,trans-7g which was then
purified by column cromatography (petroleum ether/ethyl ace-
tate 3:1), giving 62 mg (53%) of trans,trans-7g. 1H NMR (CDCl3,
200 MHz) δ: 7.5-7.2 (5H, m); 5.44 (1H, d, J ) 7.0 Hz); 4.56
(1H, app q, J ) 6.8 Hz); 3.84 (2H, d, J ) 6.2 Hz); 2.61 (1H, app
quint, J ) 6.6 Hz); 2.3-2.0 (1H, bs); 2.0-1.6 (2H, m); 1.5-1.2
(6H, m); 0.89 (3H, t, J ) 6.2 Hz). 13C NMR (CDCl3, 75.45 MHz)
δ: 142.8; 128.4; 127.6; 125.3; 81.2; 80.8; 62.8; 52.0; 37.2; 31.6;
23.8; 22.5; 13.9. MS (m/z): 233 (0.4, M+ - 1); 128 (7, M+ - C7H6-
CO); 117 (38); 107 (81); 81 (36); 79 (63); 77 (37); 68 (31); 67 (35);
57 (100); 55 (40); 54 (34). Anal. Calcd for C15H22O2: C, 76.88; H,
9.46. Found: C, 77.01; H, 9.12.
1-Tr ia lk ylsilyloct-1-en -3-ol.24 1-Trialkylsilyloct-1-yn-3-ol (7
mmol) in THF (6.6 mL) was added to Na[AlH2(OCH2CH2OCH3)2]
(3.5 mL of 3.4 M solution in toluene, 12 mmol) in Et2O (11 mL)
at 0 °C. The mixture was then warmed to 25 °C and stirred for
16 h. After cooling to 0 °C, water (8 mL) and 3 N HCl (8 mL)
were slowly added. The organic solution was separated and the
aqueous solution extracted with hexanes-Et2O 1:1. The com-
bined organic layers were washed with aqueous NaHCO3 and
brine and dried.
1-Tr im eth ylsilyloct-1-en -3-ol.31 After the solvent was evapo-
rated, 1.15 g (82%) of crude was obtained and purified by column
chromatography (eluent petroleum ether/ethyl acetate 7:1),
affording 0.63 g (45%) of product. 1H NMR (CDCl3, 200 MHz) δ:
6.04 (1H, dd, J ) 18.6, 5.0 Hz); 5.83 (1H, dd, J ) 18.6, 1.0 Hz);
4.2-4.0 (1H, m); 1.5-1.2 (8H, m); 0.88 (3H, t, J ) 6.6 Hz); 0.06
(9H, s).
1-Tr iisop r op ylsilyloct -1-en -3-ol. After the solvent was
evaporated, 1.73 g (87%) of crude was obtained and purified by
column chromatography (eluent petroleum ether/ ethyl acetate
8:1), affording 0.80 g (40%) of product. 1H NMR (CDCl3, 200
MHz) δ: 6.10 (1H, dd, J ) 19.2, 5.4 Hz); 5.71 (1H, dd, J ) 19.2,
1.6 Hz); 4.2-4.0 (1H, m); 1.5-1.2 (8H, m); 1.05 (18H, m); 1.1-
1.0 (3H, m,); 0.88 (3H, t, J ) 6.2 Hz).
(E)-1-Tr ia lk ylsilyl-1,2-ep oxy-3-octa n ol. L-(+)-Diisopropyl-
tartrate (0.84 g, 3.6 mmol) was added to Ti(i-OPr)4 (0.85 g, 3
mmol), in CH2Cl2 (26 mL), at -20 °C. After 10 min, 1-trialkyl-
(2,3-tr a n s-3,4-tr a n s)-2-P h en yl-3-(1-h yd r oxym et h yl)-4-
(ter t-bu t yld im et h ylsilyloxym et h yl)oxet a n e (tr a n s,tr a n s-
7h ).30 The procedure with LIDAKOR was used on epoxide 6h ,
obtaining 137 mg (89%) of trans,trans-7h which was then
purified by column cromatography (petroleum ether/ethyl ace-
(30) J ung, M. E.; Nichols, C. J . Tetrahedron Lett. 1996, 37, 7667.
(31) Falck-Pedersen, M. L.; Benneche, T.; Undheim, K. Acta Chem.
Scand. 1989, 43, 251.

Notes
J . Org. Chem., Vol. 66, No. 9, 2001 3205
silyloct-1-en-3-ol (3 mmol) was added, and the resulting solution
was stirred for an additional 10 min. t-BuOOH (0.82 mL of a
5.5 M solution in decane, dried over molecular sieves, 4.5 mmol)
was slowly added. After 12 h, Me2S (0.66 mL, 9 mmol) was slowly
added, and the mixture was stirred for 30 min at -20 °C. Then
10% citric acid (2 mL), Et2O (26 mL), NaF (2.1 g), and Celite
(1.2 g) were added sequentially. The resulting mixture was
stirred for 30 min at 25 °C, filtered through a pad of Celite, and
washed with Et2O.
(CDCl3, 200 MHz) δ: 5.90 (1H, ddt, J ) 17.2, 10.2, 5.6 Hz); 5.24
(1H, dq, J ) 17.2, 1.4 Hz); 5.15 (1H, dq, J ) 10.2, 1.4 Hz); 4.05
(2H, AB system); 3.2-3.0 (1H, m); 2.89 (1H, dd, J ) 5.4, 3.2
Hz); 2.37 (1H, d, J ) 3.2 Hz); 1.7-1.2 (11H, m); 1.10 (18H, s);
0.89 (3H, t, J ) 6.6 Hz). 13C NMR (CDCl3, 75.45 MHz): 135.1;
116.8; 80.1; 71.3; 57.0; 48.0; 33.3; 31.9; 25.0; 22.5; 18.5; 14.0;
10.4. MS (m/z): 297 (1, M+ - (CH3)3CH); 255 (11); 131 (22); 129
(80); 127 (25); 115 (57); 113 (20); 103 (51); 101 (100); 99 (75); 87
(55); 85 (41); 75 (76); 73 (50); 71 (46); 61 (58); 59 (91); 55 (27).
Anal. Calcd for C20H40O2Si: C, 70.52; H, 11.84. Found: C, 70.41;
H, 11.96.
(E)-(1S,2S,3S)-1-Tr im eth ylsilyl-1,2-ep oxy-3-octa n ol.19 Af-
ter the solvent was evaporated, the residue was purified by
column chromatography with triethylamine deactivated silica
gel (eluent: petroleum ether/ethyl acetate 7:1) to afford 0.30 g
of pure epoxide. 1H NMR (CDCl3, 200 MHz): 3.9-3.8 (1H, m);
2.87 (1H, app t, J ) 3.6 Hz); 2.36 (1H, d, J ) 3.6 Hz); 1.82 (1H,
app d, J ) 1.8 Hz); 1.6-1.2 (8H, m); 0.89 (3H, t, J ) 6.6 Hz);
0.07 (9H, s).
(E )-(1S ,2S ,3S )-1-Tr iisop r op ylsilyl-1,2-e p oxy-3-oct a n -
ol.24 After the solvent was evaporated, we obtained 0.79 g of
crude which we used directly in the following reaction. 1H NMR
(CDCl3, 200 MHz): 3.9-3.8 (1H, m); 3.04 (1H, app t, J ) 3.6
Hz); 2.47 (1H, d, J ) 3.6 Hz); 1.6-1.2 (12H, m); 1.25 (18H, d, J
) 5.0 Hz), 0.89 (3H, t, J ) 6.6 Hz).
(E)-(1S,2S,3S)-1-Tr ia lk ylsilyl-3-(2-p r op en oxy)-1,2-ep oxy-
octa n e. The epoxy alcohol (1.4 mmol) was dissolved in DMF
(1.6 mL) and, after cooling to -5 °C, a suspension of NaH (0.06
g, 1.46 mmol) in DMF (1.6 mL) was added during 30 min. After
an additional 30 min, a solution of CH2dCHCH2Br (0.25 g, 2.1
mmol) in DMF (1.6 mL) was added. The mixture warmed to 25
°C and then stirred for 5 h before it was treated with H2O (1.6
mL) and extracted with ether. The organic phase was washed
with H2O and saturated NaCl and dried.
(E)-(1S,2S,3S)-1-Tr im et h ylsilyl-3-(2-p r op en oxy)-1,2-ep -
oxyocta n e. After evaporation of the solvent, the residue was
purified by column chromatography (eluent: petroleum ether/
dichloromethane 3:1) to afford 0.26 g (71%) of 9k . 1H NMR
(CDCl3, 200 MHz): 5.89 (1H, ddt, J ) 17.2, 10.2, 5.6 Hz); 5.25
(1H, dq, J ) 17.2, 1.6 Hz); 5.15 (1H, dq, J ) 10.2, 1.6 Hz); 4.03
(2H, AB system); 3.2-3.0 (1H, m); 2.71 (1H, dd, J ) 5.8, 3.4
Hz); 2.25 (1H, app d, J ) 3.4); 1.7-1.2 (8H, m); 0.89 (3H, t, J )
6.6 Hz); 0.08 (9H, s). 13C NMR (CDCl3, 75.45 MHz): 135.1; 116.6;
79.8; 70.9; 57.0; 50.4; 33.4; 31.8; 24.8; 22.5; 14.0; -3.80. MS (m/
z): 199 (1, M+-C4H7); 155 (14); 143 (35); 129 (70); 115 (37); 99
(36); 85 (29); 81 (23); 75 (90); 74 (23); 73 (100, (CH3)3Si)); 71 (29);
59 (69); 55 (44). Anal. Calcd for C14H28O2Si: C, 65.57; H, 11.00.
Found: C, 65.41; H, 10.86.
cis-(2S,3R)-2-P en tyl-3-(tr im eth ylsilyloxy)-2,3,4,5-tetr ah y-
d r oxep in e 11k . The general procedure with LICKOR was used
obtaining 124 mg (97%) of a crude product which was then
purified by column chromatography (petroleum ether/ethyl
acetate 7:1), giving 92 mg (72%) of 11k . 1H NMR (CDCl3, 200
MHz): 6.22 (1H, dt, J ) 6.2, 2.2 Hz); 4.76 (1H, app td, J ) 6.2,
4.0 Hz); 3.8-3.6 (2H, m); 2.7-2.5 (1H, m); 2.0-1.6 (2H, m); 1.6-
1.0 (9H, m); 0.89 (3H, t, J ) 6.6 Hz); 0.06 (9H, s).13C NMR
(CDCl3, 75.45 MHz): 148.1; 109.6; 85.8; 75.5; 38.1; 35.9; 33.4;
31.8; 25.4; 22.6; 14.0; -1.27. Anal. Calcd for C14H28O2Si: C,
65.57; H, 11.00. Found: C, 65.61; H, 11.16.
cis-(2S,3R)-2-P en tyl-3-(tr iisop r op ylsilyloxy)-2,3,4,5-tet-
r a h yd r oxep in e 11l a n d (2,3-tr a n s-3,4-tr a n s)-2-Vin yl-3-[(1-
h yd r oxy-1-tr iisop r op ylsilyl)m eth yl]-4-p en tyloxeta n e 10l.
The general procedure with LICKOR was used obtaining 155
mg (91%) of a crude product as a mixture 11l:10l 28:72 which
was then purified by column chromatography (petroleum ether/
ethyl acetate 8:1), giving 32 mg of (11l) and 98 mg of (10l) (total
yield 76%).
11l. 1H NMR (CDCl3, 200 MHz) δ: 6.27 (1H, app d, J ) 6.4
Hz); 4.91 (1H, app q, J ) 5.8 Hz); 3.80 (1H, app q, J ) 6.6 Hz);
3.58 (1H, ddd, J ) 8.6, 7.6, 2.8 Hz); 2.5-2.3 (1H, m); 2.2-2.0
(1H, m); 1.8-1.2 (10H, m); 1.2-1.0 (21H, m); 0.89 (3H, t, J )
6.6 Hz). MS (m/z): 297 (43); 197 (13); 159 (23); 157 (41); 131
(46); 129 (23); 115 (49); 103 (58); 101 (20); 87 (40); 81 (25); 75
(60); 73 (55); 71 (25); 68 (23); 67 (49); 61 (32); 59 (100).
10l. 1H NMR (CDCl3, 200 MHz) δ: 5.96 (1H, ddd, J ) 16.8,
10.2, 6.6 Hz); 5.22 (1H, app dt, J ) 10.2, 1.4 Hz); 5.11 (1H, app
dt, J ) 10.2, 1.4 Hz); 4.51 (1H, app t, J ) 6.8 Hz); 4.02 (1H, app
t, J ) 7.2 Hz); 3.6-3.4 (1H, m); 1.6-1.2 (10H, m); 1.2-1.0 (21H,
s); 0.88 (3H, t, J ) 7.4 Hz). 13C NMR (CDCl3, 75.45 MHz): 140.1;
115.1; 83.8; 80.3; 79.7; 37.9; 33.1; 32.0; 25.8; 22.5; 18.9; 14.0;
11.5. MS (m/z): 297 (6, M+ - (CH3)2CH); 197 (20); 131 (83); 115
(29); 103 (100); 89 (22); 87 (33); 83 (25); 75 (97); 73 (47); 71 (23);
61 (58); 59 (74); 55 (24). Anal. Calcd for C20H40O2Si: C, 70.52;
H, 11.84. Found: C, 70.61; H, 11.90.
(E)-(1S,2S,3S)-1-Tr iisop r op ylsilyl-3-(2-p r op en oxy)-1,2-
ep oxyocta n e. After evaporation of the solvent, the residue was
purified by column chromatography (eluent: petroleum ether/
dichloromethane 3:1) to afford 0.31 g (65%) of 9l. 1H NMR
J O0005924