Synthesis of cholestanes containing an oxygenated 14α-methyl group

Abstract

Hydrocyanation of 3β-acetoxy-5α-cholest-8(14)-en-7-one has been achieved by reaction with diethylaluminium cyanide. The resulting 14α-cyano-7-ketone was reduced with sodium borohydride to the 7α-hydroxy-compound, the methanesulphonate of which, when refluxed in collidine, gave 3β-acetoxy-5α-cholest-7-ene-14α-carbonitrile. Reduction of the cyano-group with di-isobutylaluminium hydride afforded 3β-hydroxy-5α-cholest-7-ene-14α-carbaldehyde, which was transformed with lithium aluminium hydride into 14α-hydroxymethyl-5α-cholest-7-en-3β-ol.