STEROIDS CONTAINING A KETO GROUP AT POSITION 23, THEIR PREPARATION, THEIR USE IN THE PREPARATION OF COMPOUNDS OF THE 20-KETO-PREGNANE ,SERIES, AND INTERMEDIATES OF THIS USE

摘要

Compounds (I): …IMAGE… in which:… R1 is hydrogen or methyl,… R2 is methyl or ethyl,… the nuclei A, B, C and D carry optionally one or more double bonds and are optionally substituted by one or more functional groups or by one or more atoms or radicals,… R is halogen, hydroxyl, alkoxy, aralkoxy, alkylthio, arylthio, aralkylthio or …IMAGE…