To a solution of alkene 182 (1.05 g, 3.23 mmol) in t-butyl alcohol (50 mL) were successively added water (10 mL), solid sodium bicarbonate (2.71 g, 32.3 mmol), sodium periodate (4.15 g, 19.38 mmol), and osmium tetroxide (8 mg, 0.032 mmol). The mixture turned light brown and a precipitate formed in large amount, making magnetic stirring impossible so the mixture was shaken by hand every 10 minutes for 3.5 hours and the brownish color almost disappeared. The reaction was quenched with a 10% aqueous solution of sodium thiosulfate. After 30 minutes, the white precipitate was filtered off and rinsed with diethyl ether. The filtrate was concentrated in vacuo. The residue was partitioned between diethyl ether and water. The aqueous layer was extracted (2×50 mL) with diethyl ether. The combined organic layers were washed successively with a 10% aqueous solution of sodium thiosulfate, water and brine, dried (MgSO4), and concentrated in vacuo, yielding the title compound 183 as a crude oil in 91% yield (1.05 g). 1H NMR: (300 MHz, CDCl3) δ: 9.73 (t, J=1.9 Hz, 1H), 7.83-7.78 (m, 3H), 7.69 (s, 1H), 7.49-7.43 (m, 3H), 4.80 (t, J=6.9 Hz, 1H), 2.39 (td, J=7.1, 1.6 Hz, 2H), 1.81-1.55 (m, 4H), 1.43-1.25 (m, 2H) 0.90 (s, 9H), 0.04 (s, 3H), −0.15 (s, 3H). MS (ESI) 225 (M+1-TBSO).
