New semisynthetic cephalosporins are described whose structures are characterized by having an .alpha.-oxyimino group in the 7-acetamido moiety and a sulfosubstituted tetrazolylthiomethyl group at position 3. The compounds are active antibacterial agents especially against Gram negative organisms.
The compounds of this invention are cephalosporins having various acyl substituents at the 7-position and an alkanesulfonamidoalkyl substituted tetrazolylthiomethyl group at the 3-position of the cephem nucleus and intermediates for the preparation thereof. The 7-acylated compounds have antibacterial activity.