| abstract |
Compounds of formula (I) are antibacterial agents wherein: R3 and R4, taken together with the carbon atoms to which they are respectively attached, form an optionally substituted saturated carbocyclic or heterocyclic ring of 5 to 16 atoms, which may be benz-fused or fused to a second optionally substituted saturated carbocyclic or heterocyclic ring of 5 to 16 atoms; and R1 and R2 are as defined in the specification. |