17,20-EPOXIDE DERIVATIVES OF PREGNANE, THEIR PREPARATION ANDTHEIR APPLICATION TO THE PREPARATION OF CORTISONE DERIVATIVES AND INTERMEDIATES

摘要

The invention relates to compounds (I): IMG (I) R = oxo or .beta.-OH and A and B represent a free or protected 3-keto .DELTA.4 or.DELTA.1,4 residue, their preparation, their application to the preparation of the compounds (A): IMG (A) R3 is a protecting group for the hydroxy radical, as well as intermediates.