| abstract |
Processes for production of stable, crystalline cephalosporin intermediates with the formula: <IMAGE> and <IMAGE> in which X is HJ or HCl, and Nu and Nu+ are certain nitrogenous, heterocyclic rings which are attached via a sulphur atom or a ring nitrogen atom, and which are essentially free of δ2 isomers; processes for intermediates in the production of the aforesaid compounds; and processes for production of broad-spectrum cephalosporin antibiotics. |