Intermediate products for the preparation of Z-cephalosporins
申请人:Bayer Aktiengesellschaft
公开号:US04500716A1
公开(公告)日:1985-02-19
Highly active substantially pure Z-isomers of cephalosporins are produced by the following synthesis: ##STR1## in which R.sup.1, R.sup.4 and R.sup.5 ae various organic radicals, R.sup.2 is alkoxycarbonyl, Y is Cl, Br or --O--SO.sub.2 --R.sup.5, and X is a conventional cephalosporin substituent. Many of the intermediates are new, especially in pure Z-form.