METHOD OF PREPARING PREGN-4-ENE DERIVATIVES

Novel DELTA 4-pregnenes of the formula I wherein X1 is selected from the group consisting of =O and Y is selected from the group consisting of hydrogen and halogen, R1 is selected from the group consisting of hydrogen and acyl of an organic carboxylic acid of 1 to 18 carbon atoms, X2 is selected from the group consisting of hydrogen and -OH, R in the 16 alpha - or beta -position is selected from the group consisting of hydrogen, -OH and methyl, Z is selected from the group consisting of (1) -OH, (2) alkoxy of 1 to 12 carbon atoms, (3) cycloalkoxy of 3 to 12 carbon atoms, (4) acyloxy of an organic carboxylic acid of 1 to 18 carbon atoms, (5) wherein W is a hydrocarbon of 1 to 12 carbon atoms, (6) wherein R2 is hydrogen or alkyl of 1 to 12 carbon atoms, (7) wherein R3 is a hydrocarbon of 1 to 12 carbon atoms and (8) the dotted line in the A ring indicates the optional presence of a double bond in the 1(2)-position and A and B are both hydrogen or A is methyl, chlorine or fluorine while B is hydrogen or A and B may form a double bond in the 6(7)-position with the proviso that if the A ring has a 1(2) double bond, A is hydrogen or fluorine, B is hydrogen, Y is hydrogen or fluorine, X2 is hydrogen or -OH, R is methyl and Z is not -OH having a very marked antiallergic activity with a reduced anti-inflammatory activity and a process for their preparation.