Synthesis of Calicoferol E

Abstract

A concise linear synthesis of 9,10 secosteroid Calicoferol E 6 has been completed. Key features of the process include: (i) the preparation of hitherto unknown 9α-hydroxycholest-1, 4-diene-3-one 5 from commercially available 5α-cholestan-3β-ol using conventional chemistry; (ii) the acid catalyzed rearrangement of 5 to give 6.