Steroids and Walden inversion. Part LX. Some reactions of the epimeric 5α-cholestan-1-ols and the solvolysis of their toluene-p-sulphonates

Abstract

5α-Cholestan-1a-ol with phosphorus pentachloride or thionyl chloride gives a mixture of 5α-cholest-1-ene, 1β-methyl-19-norcholest-5(10)-ene, and 1β-methyl-19-nor-5α-cholest-9-ene, whilst solvolysis of 5α-cholestan-1α-yl toluene-p-sulphonate in buffered aqueous acetone at 65° gives a similar mixture of the same three olefins and some 5α-cholestan-1α-ol. 5α-Cholestan-1β-ol with the same reagents gives a single crystalline olefin, 9aζ A-nor-B-homo-19-norcholest-5(10)-ene, whilst solvolysis of 5α-cholestan-1β-yl toluene-p-sulphonate yields mainly the non-crystalline 9a-methylene-A-nor-B-homo-19-nor-5α-cholestane, and some 5α-cholestan-1β-ol.