| abstract |
This invention provides novel cephalosporanic acids and esters thereof having the general formula <IMAGE> wherein R2 is hydrogen, lower alkyl, lower alkenyl, lower alkynyl, cyclo(lower)alkyl or acyl, R3 is hydrogen, lower alkyl, lower alkoxy, lower alkanoyloxy, and R4 is hydrogen, pivaloyloxymethyl, acetoxymethyl, 1-acetoxyethyl, 5-methyl-2-oxo-1, 3-dioxolen-4-ylmethyl or 4-glycyloxybenzoyloxymethyl. These compounds, especially esters, are useful as broad spectrum antibiotics in the treatment and prevention of infectious diseases of mammals, and for other purposes known in the art.n[US4708955A] |