process for the preparation of 17 monoesters from 17 alpha -, 20 -, 21 - dihydroxy keto steroids and formed the pregnaan series, pharmaceutical preparation with ontstekingswerende properties.

摘要

This invention relates to an improved process for the preparation of 17-monoesters of 17 alpha , 21-dihydroxy-20-keto-steroids which consists in carrying out the hydrolysis of corresponding 17,21-cyclic orthoesters in a buffered aqueous-organic medium at a pH from about 4 to about 6. This invention also relates to new 17-esters of 17 alpha , 21-dihydroxy-steroids having an epoxy group at the 9 beta , 11 beta -position, useful as intermediates for the preparation of therapeutically active 17-esters.