HCID 14304771, compound → HCID 70300251, compound

Participants

Reaction Steps

Under an argon atmosphere, a solution of potassium t-butoxide (4.13 g, 36.8 mmol) in dry tetrahydrofuran (500 ml) was cooled to -78° C., and a solution of 1α,3β-bis(t-butyldimethylsilyloxy)-17-oxoandrosta-5,7-diene (13.0 g, 24.5 mmol) in tetrahydrofuran (40 ml) was added dropwise. After the mixture was stirred at the same temperature for 1 hour, a solution of 2-(phenylsulfonyl)-3-phenyloxazyldine (9.62 g, 36.8 mmol) in tetrahydrofuran (40 ml) was added dropwise and the mixture was further stirred at -78° C. for 1.5 hour. The reaction mixture was quenched with an aqueous saturated ammonium chloride solution, poured into water and extracted with ethyl acetate. The organic layer was washed with brine and dried over anhydrous magnesium sulfate. The mixture was concentrated under reduced pressure and the deposited solids were filtered, then the filtrate was concentrated again and the residue was purified by column chromatography on silica gel (hexane:ethyl acetate:chloroform=7:1:2) to give the title compound as a white solid (3.10 g, 23%).

Provenance & Evidence