New .beta.-lactam acetic acid derivatives I ##STR1## wherein R represents alkyl, alkyl substituted with amino, protected amino, mono- or di-alkylamino, hydroxy, protected hydroxy or alkoxy, and alkenyl, and their salts are useful as intermediates for preparing 1-azabicyclo [3.2.0]hept-2-ene antibiotics II ##STR2## The process for preparing the .beta.-lactam acetic acid derivatives I as well as the overall process which starting from the acids I leads to the antibiotics II are also claimed.
新的.beta.-内酰胺
乙酸衍
生物I ##STR1## 其中R代表烷基,
氨基取代的烷基,保护的
氨基,单烷基或双烷基
氨基,羟基,保护的羟基或烷氧基,以及烯基,它们的盐在制备1-
氮杂双环[3.2.0]庚-2-烯类抗生素II ##STR2## 的中间体中是有用的。制备.beta.-内酰胺
乙酸衍
生物I的过程以及从I酸开始导致抗生素II的整个过程也被要求。