Triethylamine → 17-Acetylthiomethyl-1alpha,3beta-bis(tert-butyldimethylsilyloxy)androsta-5,7,16-triene

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Reaction Steps

To a solution of 1α,3β-bis(tert-butyldimethylsilyloxy)-17-(hydroxymethyl)androsta-5,7,16-triene (4.00 g, 7.34 mmol) in tetrahydrofuran (70 ml), was added triethylamine (4.10 ml, 29.4 mmol), followed by the dropwise addition of methanesulfonyl chloride (1.70 ml, 22.0 mmol) at −10° C. and stirring for 20 min. The reaction mixture was warmed to room temperature and a solution of potassium thioacetate (3.73 g, 29.4 mmol) in dimethylsulfoxide (70 ml) was added. After stirring for 30 min., the mixture was diluted with hexane, washed with water, the organic layer was dried over anhydrous magnesium sulfate and evaporated for removing the solvent. The thus obtained residue was purified by silica gel column chromatography (hexane:ethyl acetate=15:1) to give the titled compound (3.91 g, 88%) as a colorless oil.

Provenance & Evidence