abstract |
PURPOSE: 3,7-Di-substd. -3-cephem-4-carboxylic acid derivs. I[R 1 is II, III or IV (X is S, O, imino or acylimino);R 2 is H or lower alkyl;R 3 is acyloxy or (lower alkyl-substd.)heterocyclic thio] and their salts, e.g. 7-[2-(2,3-dihydro-1,4oxathine-6-yl)-2-methoxyiminoacetamido] cephalosporanic acid (syn isomer). n COPYRIGHT: (C)1978,JPO&Japio |