Transformations of cyclopropanol intermediates. 5. Preparation and reactions of 1-hydroxy-1,5.alpha.-cyclocholestan-7-one

Abstract

Cholest-5-ene-1,7-dione, a new polyfunctional steroid, gave l-hydroxy-l,5«-cyclocholestan-7-one (6) on dissolving metal reduction. Acidand base-catalyzed isomerizations of 6 were studied and the results compared with corresponding reactions of the parent cyclopropanol la. The chief rearrangement products from 6 were the cis and trans 1,7-diketo steroids 10 and 11 and the ring-A spiro epimers 12 and 13. Surprisingly, no B-norsteroid products were obtained despite the isolation of an isomer of 6, 7-hydroxy-5,7d-cyclocholestan-l-one ( 14), from the base-induced reaction of 6. Ring-cleavage reactions of reduced derivatives of 6 and 14 were also examined.

Steroids: reactions and partial syntheses

“…On treatment of (183) with a very mild base, the primary product is the 5~,7~-cyclo-compound (1 87), which is converted, with strong base, into (184) and (186). 223 Reduction of 6-nitrocholesteryl acetate with lithium dimethylcopper gives the E-oxime of 3a,5a-cyclocholestan-6-one, from which the ketone is obtained by treatment with sodium bisulphite. *'j Mild reagents for the conversion of a 6-oxo-3~-tosyloxy-5c-steroid into the 3a75a-cyclo-6-one are tetramethylguanidine at 60 "C for 5 minutes or benzyltrimethylammonium hydroxide in pyridine at 60 "C for 10 minutes.…”