| 摘要 |
The invention provides the compound of the formula (I): <CHEM> wherein R is a hydrogen atom or a methyl, methoxyl, hydroxymethyl or nitrile group; R<1> is a hydrogen atom or a lower alkyl, aralkyl, phenyl or inertly substituted lower alkyl, aralkyl or phenyl group; R<2> is a hydrogen atom or a lower alkyl, aralkyl, phenyl or inertly substituted lower alkyl, aralkyl or phenyl group; and R<3> is lower alkyl, aralkyl, phenyl or inertly substituted lower alkyl, aralkyl or phenyl group; any of said groups R<1>, R<2> and R<3> being optionally interlinked to form a ring of 5-7 atoms. These compounds are useful as anti-bacterial agents, ss-lactamase inhibitors and chemical intermediates. Their preparation is described. |
