NEW PROCESS FOR PRODUCING PENEM ESTERS

摘要

PCT No. PCT/EP91/00522 Sec. 371 Date Sep. 21, 1992 Sec. 102(e) Date Sep. 21, 1992 PCT Filed Mar. 18, 1991 PCT Pub. No. WO91/14691 PCT Pub. Date Oct. 3, 1991.A process for preparing penem esters by reacting (II) wherein R1 is a hydroxy protecting group and X is a C1-C10 alkyl or aryl group, with (III) wherein R2 is hydrogen or a C1-C6 alkyl group in the presence of an anhydrous organic solvent, condensing the product with -OCOOR3 group and then cyclizing.