GB966102A - Novel cyclopentanophenanthrene compounds and a process for the production thereof - Google Patents

Abstract

The invention comprises 6b , 19-oxido pregnanes and 6b , 19-lactones of the general formulae: <FORM:0966102/C1/1> in which Y represents keto, b -hydroxy or b -acyloxy; X represents b -hydroxy or b -acyloxy; R represents hydrogen or a hydrocarbon carboxylic acyl group containing less than 12 carbon atoms; R1 represents hydrogen, hydroxy or acyloxy; Z represents a double bond between C-1,2 and C-4,5 or a saturated linkage between C-1,2 and C-4,5. The compounds are prepared from 6b -hydroxy-tigogenin acetate by reaction with lead tetra-acetate, and degradation of the side chain of the resulting 6b , 19-oxido tigogenin acetate by conventional methods to give a 3b -acyloxy-6b , 19-oxido-D 16-5a -pregnen-20-one, which may then be converted to the 16a , 17a -epoxide with H2O2, the epoxide ring cleaved with HBr to give 6b , 19-oxido-16b -bromo-5a -pregnane-3b 17a -diol-20-one, and the latter subjected to reductive debromination to give 6b , 19-oxido-5a -pregnane-3b , 17a -diol-20-one. Subsequent transformations by standard procedures furnish the 6b , 19-oxido compounds of the invention. Oxidation of 6b , 19-oxido-pregnane-3b , 17a -diol-20-dione diacylate and 6b , 19-oxido-5a -pregnan-3b -ol-20-one acylate with chromic acid yield the corresponding 6, 19-lactones which are then saponified and converted into the corresponding 3-keto compounds with chromic acid. The invention is illustrated by fifteen detailed examples. 6b -Hydroxy-tigogenin acetate is prepared from diosgenin acetate by treatment with hypobromous acid, oxidation of the resulting 5a -bromo-6b -hydroxy derivative, elimination of the bromine atom from the 5a -bromo-6-keto compound, and then hydrogenation of the keto group to give the corresponding 6b -ol derivative. Specification 966,101 is referred to.