| abstract |
Cephalosporin intermediates of the formulas <IMAGE> and <IMAGE> wherein R is lower alkyl, 2,2,2-trichloroethyl, diphenylmethyl, p-methoxybenzyl, or p-nitrobenzyl; R1 is lower alkyl or phenyl; R2 is hydrogen or acetoxy; R4 is methyl or ethyl; and R5 is hydrogen, methyl, or methoxy; are disclosed. Methods of reacting these intermediates to prepare antibacterially active cephalosporins are disclosed. |