A stirred solution of 0.60 g of (E)-17β-hydroxyiminomethyl-5β-androstane-3β,14β-diol (prepared following the procedure described in DE 4,227,605 for similar compounds) in 6 ml of methanol was acidified to pH 3 with 1N HCl. 0.30 g of NaBH3CN were added and 0.1N HCl was continuously added, by means of a pH-stat, to maintain pH 2.8+3.0. After 6 hr, 0.15 g of NaBH3CN were added and the reaction was left on stirring overnight. The solution was basified to pH 10 with 2.5N NaOH and methanol was evaporated under reduced pressure. The mixture was extracted with ethyl acetate; the organic layer was dried over anhydrous sodium sulfate and evaporated to dryness under reduced pressure. The residue was purified by flash-chromatography (SiO2) using cyclohexane/ethyl acetate 20/80 as the eluant; the fractions containing the title compound were collected and evaporated to dryness under reduced pressure. The residue was dissolved with diethyl ether/ethyl acetate and the solution was added with the stoichiometric amount of oxalic acid to give 0.45 g of the title compound (I-ah), as a white solid, oxalate.
