3,3-(Ethylenedioxy)-4,4-dimethyl-6alpha-hydroxymethyl-17beta-tert-butyl-dimethylsilyloxyandrostan-7-one → 4,4-Dimethyl-6alpha-hydroxymethyl-7alpha,17beta-dihydroxyandrostan-3-one

Participants

Reaction Steps

To a stirred solution of 3,3-(ethylenedioxy)-4,4-dimethyl-6α-hydroxymethyl-17β-tert-butyldimethylsilyloxyandrostan-7-one (Preparation 9—Step 5, 1.0 g) in MeOH (40 ml) NaBH4 (140 mg) was added at 0° C. and the mixture was warmed to RT. After 1 h the mixture was quenched by addition of 5% NaH2PO4 and extracted with DCM. The combined organic extracts were washed with brine, dried over Na2SO4 and evaporated to dryness. The residue was dissolved in dioxane (20 ml) and 1N HCl (10 ml) was added. The resulting mixture was stirred at RT for 1 h and evaporated to dryness. The residue was purified by flash chromatography (SiO2, n-hexane/AcOEt 25/75) to give 4,4-dimethyl-6α-hydroxymethyl-7α,17β-dihydroxyandrostan-3-one in 76% yield.

Provenance & Evidence