| 摘要 |
<p>This invention relates to the preparation of 3-heterothiomethyl cephalosporanic acid esters of the formula <IMAGE> by treating a 3-methylene cephalosporin of the formula <IMAGE> with a compound of the formula HETERO-S-S-hetero or X-S-hetero IN THE PRESENCE OF A BASE WHEREIN R is a readily removable ester group, R1 is in the alpha -configuration and is hydrogen or methoxy, and X is a leaving group. The resulting 3-heterothio cephalosporin esters are treated according to known methods to remove the ester protecting group and yield the corresponding free acids which have antibacterial activity.</p> |
