Patent ID: 6369218
Filing Date: 2002-04-09
Classification: C07J

Abstract:
An isomerisation process of 6&bgr;-fluoro derivatives into the corresponding 6&agr;-fluoro derivatives of pregnane compounds of formula (I), comprising the reaction of 6&bgr;-fluorosteroids, or 6&agr;/6&bgr; isomeric mixtures, with an organic base, to obtain a 6&agr;-enriched 6&agr;/6&bgr; mixture with a 6&agr;/6&bgr; ratio higher than 95:5 where R is H or an acyl group containing 1 to 5 carbon atoms in the alkyl chain; Râ€² is OH or an acyloxy group containing 1 to 5 carbon atoms in the alkyl chain; Râ€² is H or a methyl group; or Râ€² and Râ€³, taken together, form a group, in which A and B, identical or different from each other, are H or an alkyl group containing 1 to 4 carbon atoms; X is H, Y is OH or a carbonyl group; X and Y, taken together, are an epoxy group,and where a double bond may be present between positions 1 and 2; is said isomerisation process being characterised by the fact that the said organic base contains a diazoimino group and the reaction is carried out in an aprotic polar organic solvent.