ChemInform Abstract: Synthesis of 8,14‐Epoxides of 19‐Norsteroids.

Abstract

ChemInform Abstract 8α,14α-Epoxides can be synthesized by direct oxidation of the corresponding 8(14)-olefins. The preparation of 8β,14β-epoxides becomes possible by treatment of the 8(14)-olefins with NBS and subsequent cyclization of the bromohydrins thus obtained.

Steroids: reactions and partial syntheses

“…Prolonged reaction of pennogenin 3,17-diacetate (212) with boron trifluoride etherate is now found to give the diene (214) as well as the spiroketalorthoester (21 3). 134 Both of these products are probably formed via the common intermediate (215), which arises by neigh-bouring group participation of the 17a-acetoxyl group. The structures ( 213) and ( 214) are supported by detailed spectroscopic studies.…”