反应详情

Compound (4) does not show the characteristic streaking of the epoxide (3) by thin layer chromatography, using 10% ethyl acetate/hexane as the solvent system, on silica gel plates, but rather provides a discrete band at an Rf of about 0.1-0.2. The compound treated with a protic acid (preferably 70% perchloric acid) for 2 hours to obtain the precursor (3β,5α)-3-(benzoyloxy)cholest-8(14)en-15-one (6). The precursor (6) is dissolved in a protic solvent, preferably methanol, and treated with potassium carbonate as hereinbefore described to provide the desired product (7). The alternate procedures of Scheme II for the debenzoylation may also be used.