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β-内酰胺
乙酸衍
生物I,其中R代表烷基,烷基取代
氨基,保护
氨基,单或双烷基
氨基,羟基,保护羟基或烷氧基,以及烯基,它们的盐可用作制备1-
氮杂双环[3.2.0]庚-2-烯类抗生素II的中间体。制备β-内酰胺
乙酸衍
生物I的方法以及从I酸开始导致II抗生素的整体过程也被要求。