| 摘要 |
There is described a process for the preparation of compounds of general formula (I) <CHEM> (wherein R<1> represents an amino or protected amino group, R<2> is hydrogen or a carboxyl blocking group, B is S or S -> O and the dotted line indicates that the compound is a ceph-2-em or ceph-3-em compound) or a corresponding compound having at the 4-position a group of formula -COOR<3> (where R<3> is a carboxyl blocking group) and having an associated anion A<(-)>, and salts and esters thereof which comprises reacting a compound of formula (II) |
