Process for the preparation of cephem-and isooxacephem derivatives and certain such compounds

摘要

The invention is concerned with a new process for the preparation of compounds of formula wherein R<1> is trityl, acetyl, tetrahydropyranyl or cyclopentyl; R<2> is hydrogen, hydroxy, lower alkyl, cycloalkyl, lower alkoxy, lower alkenyl, lower alkynyl, aryl, aryloxy, aryl-lower alkyl, aryl-lower alkoxy or heterocyclyl or heterocyclyl-lower alkyl; the lower alkyl, cycloalkyl, lower alkoxy, lower alkenyl, cycloalkenyl, lower alkynyl, aryl-lower alkyl, aryl, aryloxy, aryl-lower alkoxy, the heterocyclyl moieties being unsubstituted or substituted with at least one group selected from carboxy, amino, nitro, cyano, lower alkyl, lower alkoxy, hydroxy, halogen, -CONR<21>R<22>, -N(R<22>)COOR<23>, R<22>CO-, R<22>OCO- or R<22>COO-, wherein R<21> is hydrogen, lower alkyl, or cycloalkyl; R<22> is hydrogen or lower alkyl; R<23> is lower alkyl, lower alkenyl or a carboxylic acid protecting group; Y is -S- and Z is -CH2- or Y is -CH2- and Z is -O-, by acylation of a compound of formula with an activated carboxylic acid derivative of formula wherein R<3> is lower alkyl, and R<1>, R<2>, X, Y, Z have the significance given above; and it is further concerned with compounds of formula III.