New azetidine derivatives of the formula: ##STR1## wherein R.sub.1 represents a penicillin- or cephalosporin-amido group, R.sub.2 represents one of the groups of the following formulae: ##STR2## 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 ##STR3## 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, wherein 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 cephalo-sporanic and penicillanic derivatives.
                            新的azetidine衍
生物的
化学式为:##STR1## 其中R.sub.1代表
青霉素或
头孢菌素酰胺基团,R.sub.2代表以下
化学式中的一种:##STR2## 其中R.sub.4、R.sub.5和R.sub.6相同或不同,每个代表氢原子或较低的烷基或烯基基团,n代表2或3,如果
化学式IIB代表苯基,则该基团可以携带来自卤素原子和较低的烷基、烯基和苯基组的1至4个进一步的取代基,R.sub.3代表以下
化学式的
氨基团:##STR3## 其中R.sub.7代表氢原子或较低的烷基基团,R.sub.8代表较低的烷基基团,或R.sub.3代表N,N'-二取代的
肼基团,其中取代基是较低的烷基,例如N,N'-
二异丙基肼基团,或R.sub.3代表--OR.sub.9基团,其中R.sub.9代表氢原子、较低的烷基基团,该基团可以被1至3个卤素原子或1或2个苯基取代,其中苯基可以被甲氧基或硝基取代,或R.sub.9代表
苯乙酰基团或盐形成阳离子,以及
化学式I中相应的azetidine衍
生物,其中
丙烯基侧链中的双键已从2位移动到1位,这些化合物是制备
头孢菌素和
青霉素衍
生物的多功能中间体。