| 摘要 |
<p>TITLE OF INVENTION New 1-oxadethiacephalosporin derivatives and the production thereof New antibacterial 1-oxadethiacephalosporin derivatives of the genaral formula wherein R is a heterocyclic group or a group -S-Het where Het denotes a heterocyclic group, Y is a hydrogen atom or a methoxy group; x and y are each an integer of 1 to 3 is produced by a process comprising condensing a l-oxacephem compound of the formula wherein R, Y, y are as defined above; R' is a hydrogen atom or a carboxyl-protecting group; and Z is a halo group, with a sulfur-containing amino acid of the formula wherein x is as defined above,in a solvent and removing, if necessary, the residual protective group from the resultant condensation product. The new l-oxadethiacephalo-sporin derivatives and the pharmaceutically acceptable salts and esters thereof exhibit high and broad "in vitro" and "in vivo" antibacterial activity, particularly against .beta.-lactamase-producing strains of gram-negative bacteria.</p> |
