PROCESS FOR PRODUCING CEPHEME-CARBOXYLIC ACID DERIVATIVES AND PHARMACEUTICAL COMPOSITIONS CONTAINING THEM

摘要

Compounds of formula (I> wherein R<1> and R<2>, which may be the same or different, each represents a hydrogen atom or a carboxyl blocking group; R<3> represents a hydrogen atom or an amino protecting group; R<4> and R<5> each represents a hydroxy or substrtuted hydroxy group or R<4> and R<5> together represent a cyclic protected diol group; Z is -S- or -SO- ( alpha - or beta -) and the dotted line bridging the 2-, 3-, and 4-positions indicates that the compound is a ceph- 2-em or ceph-3-em compound; and salts and solvates thereof.