| abstract |
Processes for preparing stable crystalline cephalosporin intermediates corresponding to formulas (I) and (II), where X is HI or HCl, and Nu and Nu + are certain heterocyclic rings containing N linked via a sulfur atom or an atom cyclic nitrogen, respectively, which are essentially devoid of the DELTA2 isomer; process for obtaining intermediates in the preparation of the compounds described above; and methods of preparing broad spectrum cephalosporin antibiotics. |