Steroids and Walden inversion. Part LXVII. Substitution reactions of the 19-nor-5α-cholestan-2-ols

Abstract

19-Nor-5α-cholestan-2α-ol and phosphorus pentachloride give with inversion of configuration 2β-chloro-19-nor-5α-cholestane (90%) together with 2α-chloro-19-nor-5α-cholestane (<10%). 19-Nor-5α-cholestan-2β-ol and phosphorus pentachloride give with inversion of configuration 2α-chloro-19-nor-5α-cholestane (70%) and considerable amounts of olefin(s)(30%). The results obtained by use of thionyl chloride at 20° show predominant retention for the 19-nor-2α-ol, but predominant inversion for the 19-nor-2β-ol.