Lithium aluminium hydride-aluminium chloride reduction of steroidal cyclic acetals

Abstract

Lithium aluminium hydride-aluminium chloride (1 : 1, AlH₂Cl) reduction of 3,3-ethylenedioxycholest-5-ene (5), 3,3-ethylenedioxy-5α-oholestane (7), 6,6-ethyl-enedioxy-5α-cholestane (7), and 3,3-(1?- methylethylenedioxy)cholest-5-en (8a), gave the glycol ethers (9), (17), (21a), and (24), respectively. The structures of the ethers (9), (17), (21a), and (24) have been established by their spectral properties and chemical transformations. A mechanism of the hydrogenolysis is presented.