CHEM01200604012 Dibakar Goswami - Homi Bhabha National ...

organic layer was separated and the aqueous layer extracted with EtOAc (20 mL). The
combined organic extracts were washed successively with H 2 O and brine, and dried.
Removal of solvent under reduced pressure and column chromatography (silica gel, 0-5%
EtOAc/hexane) of the residue afforded pure 181. Yield: 0.760 g (71.8%); colourless oil; [
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α] D +17.2 (c 1.64, CHCl3 ); IR: 1720 cm -1 ; 1 H NMR: δ 0.74 (t, J = 7.6 Hz, 3H), 1.01 (d, J
= 6.8 Hz, 3H), 1.09 (s, 9H), 1.44-1.62 (m, 2H), 1.62-1.88 (m, 3H), 4.23-4.30 (m, 2H),
4.35-4.42 (m, 1H), 5.29-5.45 (m, 2H), 7.33-7.48 (m, 9H), 7.66-7.71 (m, 4H), 8.00-8.05 (m,
2H); 13 C NMR: δ 13.7, 14.2, 19.2, 20.9, 26.8, 31.1, 37.0, 63.2, 72.4, 127.1, 127.3, 128.1,
128.3, 128.9, 129.2, 129.3, 130.3, 132.6, 132.8, 134.1, 135.7, 135.8, 166.4. Anal. Calcd.
for C 32 H 40 O 3 Si: C, 76.75; H, 8.05%. Found: C, 76.98; H, 7.86%.
(3S,4S)- 3-Methyl-4-O-tert-butyldiphenylsilyl-octan-1,4-diol 183. A mixture of 181
(0.70 g, 1.40 mmol) and 10% Pd-C (0.03 g) in EtOH (10mL) was magnetically stirred
under a positive pressure of H 2 gas. After stirring for ~8 h, the mixture was diluted with
Et 2 O (15 ml), and the supernatant was passed through a 5 cm pad of silica gel. Removal of
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solvent under reduced pressure afforded crude 182 in almost quantitative yield. [α] D +
12.6 (c 1.2, CHCl3); colourless oil; IR: 1722 cm -1 ; 1 H NMR: δ 0.71 (t, J = 6.6 Hz, 3H),
1.05 (s merged with d, 12H), 1.10-1.14 (m, 2H), 1.25-1.35 (m, 2H), 1.37-1.40 (m, 1H),
1.79-1.92 (m, 4H), 3.56-3.63 (m, 1H), 4.17-4.31 (m, 2H), 7.32-7.44 (m, 9H), 7.63-7.94 (m,
4H), 7.95-7.98 (m, 2H); 13 C NMR: δ 13.7, 15.2, 19.4, 22.4, 26.9, 27.8, 30.6, 32.3, 34.6,
63.4, 76.8, 127.1, 127.2, 128.1, 129.2, 129.3, 130.2, 132.6, 134.5, 135.8, 166.4.
Hydrolysis of 182 (0.60 g, 1.19 mmol) with K 2 CO 3 (0.42 g, 2.98 mmol) in MeOH
(5 mL), usual work up and column chromatography (silica gel, 0-10% EtOAc/hexane)
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