3-Phosphonium and 3-phosphoranylidenecephems

3-Substituted-7-methoxy-7-amino-3-cephem-4-carboxylic acids

3-Substituted-7-substituted alkanamido-3-cephem-4-carboxylic aci

3-Vinylcephalosporin derivatives

4(Tetrazol-5-yl)-.DELTA..sup.3 -cephem compounds

4,4-disubstituted-1,4-dihydro-2H-3,1-benzoxazin-2-ones useful as

4,4-disubstituted-1,4-dihydro-2h-3,1-benzoxazin-2-ones...

4,5-Dichloro-imidazole-1-carboxylic acid aryl esters

4,5-disubstituted-2-aminopyrimidines

4-(4-Pyridinyl)isatoic anhydride

4-(Monoalkylamino)benzoic acid imidates

4-(Tetrazol-5-yl)-.DELTA..sup.3 -cephem compounds

4-(Tetrazol-5-yl)-.DELTA..sup.3 -cephem compounds

4-(Tetrazol-5-yl)-.DELTA..sup.3 -cephem compounds

4-(Tetrazol-5-yl)-.DELTA..sup.3 -cephem compounds

4-aminophenol derivatives

4-Hydroxy-3,4-dihydro-2(1H)-quinazolinethiones

4-Hydroxy-3-(3-isoxazolylcarbamoyl)-2H-1,2-benzothiazine 1,1-dio

4-monosubstituted and 4,6-disubstituted N-(.alpha.-phenylethyl)p

4-Oxo-1-pyridinyl cephalosporin derivatives