| 摘要 |
Isoclavulanic acid and derivatives of it are disclosed which have .beta.-lactamase inhibitory and antibacterial properties, the preferred compounds being of the formula (I) wherein R is hydrogen or wherein n is 0 or an integer from 1 to 6; R1 is a hydrogen or a phenol or phenoxy group and R2 is a hydrogen or halogen atom or a C1-4 alkyl, C1-4 alkoxy, -CO2R3 group where R3 is a hydrocarbon group of 1-8 carbon atoms or ; or pharmaceutically acceptable salts thereof of the group of sodium, potassium, calcium, magnesium and aluminum; or pharmaceutically acceptable esters thereof of the formula . wherein A is a hydrocarbon group of 1 to 9 carbon atoms or a hydrocarbon group of 1 to 9 carbon atoms substituted by one or more halogen, lower alkyl, lower acyl, lower etherified or acylated hydroxy groups. These compounds are prepared by isomerization of clavulanic acid or derivatives, for example in the presence of a transition metal catalyst and hydrogen, or by ultra-violet irradiation. |
