6-(substituted methylene)penems and intermediates

摘要

PCT No. PCT/EP93/02894 Sec. 371 Date Apr. 28, 1995 Sec. 102(e) Date Apr. 28, 1995 PCT Filed Oct. 20, 1993 PCT Pub. No. WO94/10178 PCT Pub. Date May 11, 1994 <IMAGE> (I) <IMAGE> (a) Compounds of formula (I) in which: R1 is hydrogen or an organic substituent group; R2 is a fused bicyclic heterocyclic ring system of general formula (a) wherein R4 and R5 are independently hydrogen or one or more substituents replacing hydrogen atoms in the ring system shown; m is 2 or 3; p is 0, 1 or 2; and R3 is hydrogen, a salt-forming cation or an ester-forming group; and the symbol =/= indicates that the double bond may be in either the E or Z configuration.