The electrochemical oxidation of cholesteryl acetate dibromide

Cholesteryl Acetate Dibromide was dissolved in carbon tetrachloride, suspended with mixing in 4.5 molar solution of sulfuric acid and electrolyzed at a lead dioxide anode. The anodically prepared film of lead dioxide, when maintained at potentials (relative to a calomel electrode) above 1.5 volts, was a catalyst for the oxidation. A new and mild oxidation took place at the catalytic electrode surface that resulted in attack on the tertiary hydrogen atom at the 25 carbon. The mildness of the oxidation prevented the decomposition of the unconverted raw material and permitted the recovery of up to 96% of the cholesteryl acetate dibromide and derivatives. Conversion of starting material ranged from 30 to 55%. The products recovered after debromination were 25-Hydroxy cholesteryl acetate and 24-Dehydrocholesteryl acetate mixed with 25-Dehydrocholesteryl acetate. The molar yield of products ranged from 85 to 93%. This work is a contribution to the technique of degrading cholesterol in a manner that makes available a method of synthesis of more valuable steroids in high yield