Process for preparing 6-methylene steroids

US4322349A · kind A · utility

Assignee

• SCHERING CORPORATION · US

Inventors

• Klaus Annen · Berlin, DE
• Henry Laurent
• Helmut Hofmeister · Berlin, DE
• Rudolf Wiechert · Berlin, DE

Key dates

• Filing date: Feb 17, 1981
• Grant date: Mar 30, 1982
• Expiry date: Feb 17, 2001

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07J71/0031
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

A process for preparing a 6-methylene-.DELTA..sup.4 -3-keto steroid of the formula ##STR1## wherein R is hydrogen, alkoxy of up to 6 carbon atoms or acyloxy of up to 6 carbon atoms wherein the acyl group is that of a carboxylic acid, and PA1 R' is the CD-ring system of a steroid of the androstane or pregnane series, PA1 comprising reacting the corresponding .DELTA..sup.4 -3-keto steroid of the formula ##STR2## with a formaldehyde derivative of the formula EQU X(CH.sub.2 O).sub.n Y wherein PA1 n is 1, 3 or an integer on the order of 100-1000, and PA1 X is C.sub.1-5 alkoxy and Y is C.sub.1-5 alkyl when n is 1, PA1 X and Y represent a single bond between the terminal C atom and the terminal O atom when n is 3, and PA1 X is hydroxy and Y is hydrogen when n is an integer on the order of 100-1000, PA1 in an inert solvent in the presence of a condensation agent which is a strong acid a strongly acidic cation exchanger or a phosphoric acid derivative.