Cephem lactones of formula (1) ##STR1## wherein R.sup.1 is hydrogen or an organic substituent of the type appearing as the 6-substituent of penicillins or as the 7-substituent of cephalosporins are produced from corresponding 4,5-halohydrin precursors thereof by dehalogenation. Novel stereoisomers of formula (1) compounds as well as novel intermediates for cephem lactone syntheses are disclosed. The cephem lactones produced according to the invention are of utility as intermediates for cephem-type antibiotics and have antibiotic properties of their own.
公式(1)的头孢内酯##STR1##其中R.sup.1是氢或者类似于
青霉素的6-取代基或者
头孢菌素的7-取代基的有机取代基,通过脱卤生成相应的4,5-卤
水合物前体。公开了公式(1)化合物的新立体异构体以及用于头孢内酯合成的新中间体。根据本发明生产的头孢内酯可作为头孢类抗生素的中间体,并且具有自己的抗生素特性。