| abstract |
This invention relates to a novel process for the preparation of 3-cyclic-ether-substituted cephalosporins of formula (I): wherein the group CO2-R1 is a carboxylic acid or a carboxylate salt and R2 has the formula (a): wherein A1 is selected form the group consisting of C¿6-10?aryl, C1-10heteroaryl and C1-10heterocyclyl; A?2¿ is selected from the group consisting of hydrogen, C¿1-6?alkyl, C3-10cycloalkyl, C6-10aryl C1-6alkyl(CO)(C1-6)alkyl-O-, HO(CO)(C1-6)alkyl, mono-(C6-10aryl)(C1-6alkyl), di-(C6-10aryl)(C1-6alkyl) and tri-(C6-10aryl)(C1-6alkyl); from a zwitterionic compound of formula (II), or from a compound of formula (V): wherein R?2¿ is as defined above and R3 is para-nitrobenzyl or allyl. The invention also relates to the preparation of the above compounds of formula (II) and (V). |