PURPOSE: To obtain a novel compound useful as an intermediate for preparation of a cortisone derivative.
CONSTITUTION: This compound of formula I [wherein R is oxo or β-hydroxy; rings A and B are each formula II or III (wherein n is 2 or 3; and R1 is an ether or ester residue)], e.g. a cyclic 3,3-(1,2-ethanediyl)acetal of a 17,20-epoxy-20- cyano-21-hydroxypregna-5-ene-3,11-dione is obtained by protecting a ketone functional group at position 3 of formula IV (wherein the dotted lines indicate that secondary C-C-bonds may exist) and then treating it with an alkyl cyanacetate of the formula: N=C-CH2-CO2R2 (wherein R6 is 1-6C alkyl) to obtain a compound of formula V, subsequently treating this compound with an epoxidation agent (preferably hydrogen peroxide), then reducing an ester functional group of this product through a method such as treating it with a sodium borohydride in ethanol and furthermore, liberating a ketone functional group at position 3 of this product.
REMI SHIYOOBAN
MISHIERU BIBA
