(0.66 g, 94%) as a clear oil. Rf 0.41 (EtOAc:hexanes 7:93); 1H-NMR (500 MHz, CDCl3) δ 0.02
(s, 3H), 0.04 (s, 3H), 0.91 (s, 9H), 0.98 (s, 3H), 1.02 (d, J = 6.5 Hz, 3H), 1.12-1.19 (m, 2H), 1.23-
1.30 (m, 2H), 1.36-1.43 (m, 3H), 1.56-1.65 (m, 1H), 1.67-1.73 (m, 1H), 1.76-1.86 (m, 2H), 1.94-
2.00 (m, 1H), 2.02-2.09 (m, 1H), 2.13-2.19 (m, 1H), 2.47 (dd, J = 15.7, 2.5 Hz, 1H), 4.01-4.04
(m, 1H), 9.70 (dd, J = 3.6, 1.4 Hz, 1H); 13C-NMR: (125 MHz, CDCl3) δ -5.2, -4.8, 13.7, 17.6,
18.0, 20.0, 23.0, 25.8 (3C), 27.6, 31.3, 34.3, 40.6, 42.3, 50.8, 53.0, 56.6, 69.3, 203.7; m/z
[훼]25
+
calculated for C20H41N2OSi 354 [M + NH4], found 354;
= + 27.0 (c 1.0 mM, CHCl3).
퐷
2.7 (R)-3-((1R,3aR,4S,7aR)-4-((tert-butyldimethylsilyl)oxy)-7a-methyloctahydro-1H-inden-1-
yl)butanoic acid (7)
Sodium phosphate monobasic monohydride (3.39 g, 24.55 mmol) was dissolved in water (32
mL). To this was added sodium chlorite (3.41 g, 37.65 mmol). The aqueous solution was then
added to a stirred solution of 6 (1.39 g, 4.09 mmol) in tert-butanol (77 mL) and 2-methyl-2-
butene (19 mL). The reaction was monitored for 1 hour until completion and then concentrated
under reduced pressure. The residue was dissolved in aqueous 0.1 M citric acid (20 mL) and
extracted with DCM (3 x 50 mL). The organic layers were washed with water (20 mL), dried over
MgSO4, and concentrated to yield pure 7 (3.2g, 99%) as a white powder. Rf 0.19
(EtOAc:hexanes 1:4); 1H-NMR (500MHz, CDCl3) δ 0.02 (s, 3H), 0.03 (s, 3H), 0.91 (s, 9H), 0.97
(s, 3H), 1.03 (d, J = 6.4 Hz, 3H), 1.08-1.19 (m, 2H), 1.25-1.42 (m, 6H), 1.55-1.65 (m, 1H), 1.66-
1.72 (m, 1H), 1.77-1.88 (m, 2H), 1.91-2.08 (m, 3H), 2.49 (d, J = 14.8, 3.2 Hz, 1H), 4.01-4.04 (m,
1H), 11.05 (bs, 1H); 13C-NMR: (125MHz, CDCl3) δ -5.2, -4.8, 13.7, 17.6, 18.0, 19.5, 23.0, 25.8
(3C), 27.3, 33.2, 34.4, 40.6, 41.2, 42.3, 53.0, 56.5, 69.4, 179.7; m/z calculated for C20H38O3Si
[훼]25
+
-
356 [M + H] , found 356; m/z calculated for C20H38O3Si 353 [M-H] , found 353;
= + 41.0 (c
퐷
1.0 mM, CHCl3).
2.8 (R)-methyl 3-((1R,3aR,4S,7aR)-4-((tert-butyldimethylsilyl)oxy)-7a-methyloctahydro-1H-
inden-1-yl)butanoate (8)
To a stirred solution of 7 (1.01 g, 2.86 mmol) in toluene (16.5 mL) and methanol (11 mL) was
added trimethylsilyl diazomethane (2.12 mL, 2 M in diethyl ether, 4.23 mmol). The reaction was
stirred for 1.5 hours at room temperature and then quenched with acetic acid. The mixture was
concentrated under reduced pressure and purified by column chromatography (EtOAc:hexanes
3:97) to yield 8 (1.05 g, quantitative) as a clear oil. Rf 0.28 (EtOAc:hexanes 3:97); 1H-NMR (500
MHz, CDCl3) δ 0.01 (s, 3H), 0.02 (s, 3H), 0.90 (s, 9H), 0.95-0.98 (m, 6H), 1.06-1.17 (m, 2H),
1.24-1.30 (m, 2H), 1.33-1.49 (m, 3H), 1.54-1.64 (m, 1H), 1.65-1.71 (m, 1H), 1.74-1.87 (m, 2H),
7