still for framstellning of 17alfa - carboxylate or neutral 17alfa - phosphate - or - karbonatestrar of 17alfa21 - dihydroxy - 20 - oxo steroids

摘要

The specification describes a process for preparing 17 alpha -carboxylate or neutral phosphate or carbonate esters of 17 alpha -21-dihydroxy-20-oxo steroids wherein a 21-carboxylate or neutral phosphate or carbonate ester of a 17 alpha ,21-dihydroxy-20-oxo-steroid is treated with a non-hydroxylic base in an anhydrous aprotic medium to remove a proton selectively from the 17 alpha -hydroxyl grouping, and the reaction mixture neutralised or acidified whereby the intermediate product is protonated. The base used in the process can be for example a carbanionoid e.g. alkali metal alkyl, or metal amide, e.g. alkali metal amide, base. The process is applicable to the preparation of a wide variety of 17-esters of the above-mentioned type. The process can also be used to prepare certain enol-aldehydes corresponding to the above-described 17-ester, a particular class of these enol-aldehydes being described in the specification as novel compounds.