| 摘要 |
<p>Compounds of general formula (I> <IMAGE> (wherein R represents a hydrogen atom or a carbamoyl protecting group, Z is S or -SO- and the dotted line indicates that the compound is a ceph-2-em or ceph-3-em compound) are prepared by reacting a compound of formula (II> <IMAGE> (wherein R, Z and the dotted line are as defined above) with a methylating agent serving to introduce an etherifying methyl group.</p> |
