Acetidine derivatives

Abstract

A new azetidine derivative of the formula: ##EQU1## wherein R.sub.1 represents a penicillin- or cephalosporin-amido group, R.sub.2 represents one of the groups of the following formulae: ##EQU2## wherein R.sub.4, R.sub.5 and R.sub.6 are the same or different and each represents a hydrogen atom or a lower alkyl or alkenyl group, n represents 2 or 3 and - in case formula IIB represents a phenyl group - this group may carry one to four further substituents selected from the group consisting of halogen atoms and lower alkyl, lower alkenyl and phenyl groups, R.sub.3 represents an amino group of the formula ##EQU3## wherein R.sub.7 represents a hydrogen atom or a lower alkyl group and R.sub.8 represents a lower alkyl group, or R.sub.3 represents a N,N'-disubstituted hydrazino group wherein the substituents are lower alkyl groups, e.g. the N,N'-diisopropylhydrazino group, or R.sub.3 represents the group --OR.sub.9, wherein R.sub.9 represents a hydrogen atom, a lower alkyl group, which group may be substituted by 1 to 3 halogen atoms or by 1 or 2 phenyl groups, werein the phenyl groups may be substituted by a methoxy or a nitro group, or R.sub.9 represents a phenacyl group or a salt-forming cation, And corresponding azetidine derivatives of formula I wherein the double bond in the propenyl side chain has been shifted from the 2- to the 1-position, which are versatile intermediates in the process of preparing cephalosporanic and penicillanic derivative.