PROCESS FOR THE PREPARATION OF 6-METHYLENE STEROIDS

摘要

The present invention provides a process for the preparation of a 6-methylene-.DELTA.4-3-keto steroid of general Partial Formula I (I), wherein R is hydrogen or an acyloxy or alkoxy group of up to 6 carbon atoms and R' is the CD-ring skeleton of a steroid of the androstane or pregnane series, which comprises treating a .DELTA.4-3-keto steroid of general Partial Formula II (II), wherein R and R' have the meanings given above, in an inert solvent, with a condensation agent at a temperature from 0-80.degree.C together with a formaldehyde derivative of the formula X(CH2O)nY wherein X is alkoxy and Y is alkyl of up to 5 carbon atoms when n is 1, or X and Y represent a C-O single bond, when n is 3, or X is hydroxy and Y is hydrogen when n is an integer of about 100-1000.