The construction of 6β,7β-methylene in steroids has received considerable attention. A facile approach to the 6β,7β-methylene unit was reported and the target compound 6β,7β-methylene androsta- 3β,5β,17-triol was conveniently synthesized from 4,6-androstodiene-3,17-dione by reduction with sodium borohydride, epoxidation with meta-chloroperbenzoic acid, reductive ring cleavage with lithium-aluminum hydride, and Simmons-Smith addi-tion in series. The reductive ring cleavage of the 4β,5β-epoxy ring in steroid came out to be C-4-O cleavage to give cis product 6-androstene-3β,5β,17β-triol in the yield of 93.0%, resisting to C-5-O cleavage, which is the key mechanism to afford the needed unit 5β-hydroxyl-6-ene for highly β-stereoselective Simmons-Smith addition to produce the target unit 6β,7β-methylene. The chemical structures of intermediates and target product were characterized by IR, ¹H NMR, MS techniques, and elemental analysis.

Key words: cyclopropanation, 6β,7β-methylen-steroid, epoxide cleavage, Simmons-Smith addition, Li-AlH₄ reduction