R. Angelaud, Y. Landais / Tetrahedron 56 (2000) 2025±2036
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Kugelrohr distillation (1458C, 0.1 mbar). 7a can also be
puri®ed using ¯ash chromatography over silica gel
(petroleum ether/NEt3 99:1). Following the one-pot pro-
cedure described above, 7a was obtained after puri®cation
m), 1.05±0.73 (4H, m), 20.06 (3H, s), 20.26 (3H, s). IR
(KBr) n 3350, 3090, 3000, 2960, 1600, 1580, 1470, 1245,
1020, 900, 840, 715, 700 cm21. MS m/z (%): 342 (M1z11,
1), 207 (100), 167 (12), 135 (40), 74 (6). Anal. Calcd for
C20H26OSSi: C 70.25, H 7.66, S 9.34. Found: C 70.19, H
7.77, S 9.27.
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through Kugelrohr distillation (11.5 g, 50%). H NMR d
7.40±7.00 (10H, m), 2.17 (2H, s), 1.00 (4H, m), 20.09
(6H, s). IR (KBr) n 3060, 3000, 2900, 1620, 1470, 1440,
1250, 900, 840, 730 cm21. MS m/z (%): 298 (M1z, 13), 207
(58), 167 (100), 151 (17), 135 (3), 121 (13), 105 (4), 91 (29).
Anal. Calcd for C18H22SSi: C 72.45, H 7.44, S 10.72, Si
9.38. Found: C 72.51, H 7.48, S 10.70, Si 9.34.
Allylsilane (8d). Following the general procedure described
above, alkylation of 7b (1 g, 4 mmol) with methyl iodide
(0.5 mL, 6 mmol) gave after ¯ash chromatography over
silica gel (petroleum ether/NEt3 99:1) the alkylated product
8d (0.95 g, 91%) (a/g ratio.95:5 measured from 1H NMR
of the crude alkylation mixture). 1H NMR d 7.40±7.09 (5H,
m), 5.95 (1H, ddd, J17.6, 10.5 and 7.2 Hz), 4.86 (2H, m),
1.91 (1H, tquint, J7.2 and 1.4 Hz), 1.11 (3H, d, J7.2 Hz),
1.05 (4H, m), 20.10 (3H, s), 20.11 (3H, s). IR (KBr) n
3100, 3000, 2950, 1640, 1600, 1490, 1260, 910, 845,
770 cm21. MS m/z (%): 248 (M1z111NH3, 4), 207 (37),
179 (3), 167 (100), 151 (13), 117 (7), 91 (11). Anal. Calcd
for C15H22SSi: C 68.67, H 8.46, S 12.20, Si 10.67. Found: C
68.75, H 8.43, S 12.22, Si 10.59.
General procedure for the alkylation of allyl- and benzyl-
silanes 7a±b
(8a). In a dry 50 mL three-necked ¯ask equipped with a
magnetic stirrer, an inlet for nitrogen, a thermometer and
a septum was placed a solution of benzylsilane 7a (0.2 g,
0.67 mmol) in dry THF (20 mL); then t-BuOK (0.11 g,
1 mmol) was added. A 1.5 M solution of n-BuLi in hexane
(0.7 mL, 1 mmol) was then added at 2808C. The mixture
was stirred for 0.75 h at 2808C, then methyl iodide (0.6 g,
2.6 mmol) was added at 2808C. The resulting mixture was
stirred for 5 min at 2808C, then quenched with a saturated
solution of NH4Cl, and the aqueous layer was extracted with
Et2O. The combined extracts were washed with a saturated
solution of NaCl, dried over MgSO4 and the solvents were
evaporated in vacuo. The residue was then puri®ed by ¯ash
chromatography over silica gel (petroleum ether/NEt3 99:1)
to give pure 8a (0.19 g, 91%). 1H NMR d 7.45±7.00 (10H,
m), 2.53 (1H, q, J7.5 Hz), 1.42 (3H, d, J7.5 Hz), 0.58
(4H, m), 20.1 (3H, s), 20.23 (3H, s). IR (KBr) n 3100,
3050, 3000, 2900, 1600, 1590, 1460, 1240, 900, 820, 780,
720, 700 cm21. MS m/z (%): 312 (M1z, 13), 224 (4), 207
(99), 167 (100), 151 (36), 135 (17), 105 (21), 91 (15). Anal.
Calcd for C19H24SSi: C 73.04, H 7.75, S 10.24, Si 8.96.
Found: C 73.12, H 7.67, S 10.18, Si 9.03.
Allyl- and vinylsilane (8e). Following the general pro-
cedure described above, alkylation of 7b (0.5 g, 2 mmol)
with 2-bromoethylbenzene (0.5 mL, 3.7 mmol) gave 8e
(0.62 g, 87%) as a 59:41 mixture of the a/g regioisomers
1
(measured from H NMR of the crude alkylation mixture),
after ¯ash chromatography over silica gel (petroleum ether/
1
NEt3 99:1). H NMR d 7.38±7.05 (20H, m), 6.06 (1H, dt,
J18.6 and 6.1 Hz), 5.72 (1H, ddd, J17, 10.3 and 9.1 Hz),
5.50 (1H, dt, J18.6 and 1.4 Hz), 4.94 (2H, m), 2.81±1.60
(11H, m), 1.05±0.93 (8H, m), 0.05 (6H, s, Si(CH3)2 g),
20.11 (3H, s, SiCH3 a), 20.13 (3H, s, SiCH3 a). MS m/z
(%): 353 (M1z11, 43), 224 (7), 207 (100), 167 (29), 151 (4),
116 (3), 74 (11).
Vinylsilane (8f). Following the general procedure described
above, alkylation of 7b (0.8 g, 3.2 mmol) with bromo-
methyldimethylphenylsilane (1.18 g, 5.2 mmol) gave the
pure ole®n 8f (0.64 g, 50%) after ¯ash chromatography
Allylsilane (8b). Following the general procedure described
above, allylation of 7a (1 g, 3.4 mmol) with allyl bromide
(0.65 g, 5.4 mmol) gave after ¯ash chromatography over
silica gel (petroleum ether/NEt3 99:1) the pure ole®n 8b
1
over silica gel (petroleum ether/NEt3 99:1). H NMR d
7.52±7.06 (10H, m), 6.11 (1H, dt, J18.5 and 5.7 Hz),
5.45 (1H, dt, J18.5 and 1.4 Hz), 2.06 (2H, m), 0.97 (4H,
m), 0.76 (2H, m), 0.28 (6H, s), 0.03 (6H, s). IR (KBr) n
3100, 3000, 2950, 1620, 1600, 1400, 1260, 1120, 840, 750,
710 cm21. MS m/z (%): 248 (M1z11, 100), 207 (84), 167
(26), 135 (44), 75 (8). Anal. Calcd for C23H32SSi2: C 69.67,
H 8.14, S 8.07, Si 14.12. Found: C 69.64, H 8.16, S 8.12, Si
14.03.
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(1.03 g, 90%). H NMR d 7.45±7.02 (10H, m), 5.64 (1H,
m), 4.99±4.82 (2H, m), 2.65±2.45 (3H, m), 1.00±0.73 (4H,
m), 20.06 (3H, s), 20.24 (3H, s). IR (KBr) n 3050, 3000,
2990, 1680, 1600, 1500, 1450, 1260, 920, 850, 820, 780,
720 cm21. MS m/z (%): 339 (M1z11, 100), 207 (65), 167
(33), 151 (6), 91 (7), 74 (16). Anal. Calcd for C21H26SSi: C
74.52, H 7.75, S 9.45, Si 8.27. Found: C 74.57, H 7.69, S
9.37, Si 8.23.
Vinylsilane (8g). Following the general procedure
described above, silylation of 7b (1 g, 4 mmol) with phenyl-
dimethylchlorosilane (1.3 mL, 6.5 mmol) gave the pure
ole®n 8g (1.5 g, 90%) after ¯ash chromatography over silica
Alcohol (8c). Following the general procedure described
above, 7a (0.4 g, 1.3 mmol) was alkylated with ethylene
glycol sulfate8 (0.33 g, 2.7 mmol). The crude product was
dissolved in Et2O (20 mL) and a 20% aqueous solution of
H2SO4 (20 mL) was added dropwise. After 1 h at rt, the
organic layer was decanted and the aqueous layer extracted
with Et2O. The combined extracts were then washed with
NaOH 10%. After drying and evaporation of the solvent in
vacuo, the crude alcohol was puri®ed by ¯ash chromato-
graphy over silica gel (petroleum ether/EtOAc 8:2) to afford
1
gel (petroleum ether/NEt3 99:1). H NMR d 7.53±7.10
(10H, m), 6.04 (1H, dt, J18.5 and 7.8 Hz), 5.30 (1H, dt,
J18.5 and 1.1 Hz), 1.86 (2H, dd, J8 and 1.1 Hz), 0.94
(4H, m), 0.29 (6H, s), 0.16 (6H, s). IR (KBr) n 3090, 3000,
2950, 1600, 1480, 1440, 1260, 1140, 920, 850, 720 cm21
.
MS m/z (%): 399 (M1z111NH3, 3), 343 (100), 233 (4), 193
(47), 167 (13), 150 (14), 117 (21), 91 (11), 74 (21). Anal.
Calcd for C22H30SSi2: C 69.08, H 7.91, S 8.37, Si 14.64.
Found: C 69.14, H 8.02, S 8.37, Si 14.75.
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the pure alcohol 8c (0.13 g, 65%). H NMR d 7.43±7.04
(10H, m), 3.60±3.35 (2H, m), 2.49 (1H, m), 2.13±2.05 (2H,