PROCESS FOR THE PREPARATION OF 1-SULFO-2-OXOAZETIDINE DERIVATIVES

摘要

1. A process for the manufacture of carboxylic acids of the general formula see diagramm : EP0096297,P23,F1 in which Het signifies an optionally amino-substituted 5- or 6-membered aromatic heterocycle containing 1 or 2 nitrogen atoms and optionally also an oxygen or sulphur atom and R signifies C1-3 -alkyl, and the group =NOCH2 COOC(R)3 is present at least partially in the syn-form, characterized by cleaving off catalytically the allyl group R**5 in an ester of the general formula see diagramm : EP0096297,P23,F2 in which Het and R have the significance given above and R**5 represents allyl, and the group =NOCH2 COOC(R)3 is present at least partially in the syn-form, with the aid of a palladium compound in the presence of triphenylphosphine or a tri(lower alkyl)phosphite and in addition in the presence of an alkali metal alkanoate or an organic base.