摘要 |
<p>A 2-substituted or unsubstituted-6-(2-oxo-1, 3-dioxolan-4-yl)-2-penem-3-carboxylic acid derivative represented by the following formula (Ia) and: <IMAGE> (Ia) wherein R is hydrogen, a light metal or a carboxy-protecting group, R1 is an alkyl group, R2 is hydrogen, methyl or a substituted methyl group. The compounds have antibacterial activity.</p> |