| abstract |
Novel cephalosporin derivatives of the formula <IMAGE> wherein R<1> is hydrogen or a conventional amino-protecting group, and R<2> is a straight or branched alkyl group containing from 1 to 4 carbon atoms, allyl, 2- butenyl or 3-butenyl, or is a group <IMAGE> wherein R<3> and R<4> each are independently hydrogen, methyl or ethyl, or R<3> and R<4>, taken together with the carbon atom to which they are attached, may be a cycloalkylidene ring containing from 3 to 5 carbon atoms, and nontoxic pharmaceutically acceptable salts, physiologically hydrolyzable esters and solvates thereof exhibit potent antibacterial activity and can be incorporated into pharmaceutical compositions. |