Process for the preparation of penem derivatives

摘要

The compounds correspond to the formula: <IMAGE> in which R<1> denotes an amino or substituted amino group, R<2> denotes a carboxy or protected carboxy group, R<3> denotes a lower alkyl group and Y denotes the radical of an amine or the azido radical. They are prepared from compounds of the formula <IMAGE> in which Z denotes a group which can be removed with the formation of HZ, by reaction with HN3 or a salt thereof or with an amine with simultaneous ring contraction. The compounds can then be converted further; they are antibacterially active.