.beta.-Lactam antibiotics having an .alpha.-formamido substituent on the carbon atom adjacent to the carbonyl group of the .beta.-lactam ring and in particular bicyclic compounds having the partial structure: ##STR1## Intermediates and processes for the preparation of the compounds are further disclosed.
具有β-内酰胺环上与羰基相邻的碳原子上的α-甲酰
氨基取代基的β-内酰胺类抗生素,特别是具有部分结构的
双环化合物:##STR1## 进一步揭示了制备这些化合物的中间体和过程。