Selective conversion of 20-methylpregna3,5,20 (21) -triene-3,21-diol diacetate to 3-oxo-20-methylpregna-4,20 (21) diene-21ylacetat

摘要

The present invention relates to the selective conversion of 20-methylpregna-3,5,20(21)-triene-3,21-diol-diacetate to 3-oxo-20-methylpregna-4,20(21)- diene-21-yl-acetate by the use of a halogenated solvent and a halogenated acid. This process provides improved recovery of 3-oxo-20-methylpregna-4,20(21)- diene-21-yl acetate which is a useful intermediate in the preparation of progesterone.