Semisynthetic cephalosporins. III₁₎ synthesis and structure activity relationships of novel orally active 7-[4-hydroxy-3-(substituted methyl)phenyl]-acetamido-3-cephem-4-carboxylic acids

A family of novel optically active α-amino-3-substituted-methyl-4-hydroxy benzene acetic acids (3) have been prepared. A number of these amino acids were converted to a group of cephalosporins (12). Compound 12A showed the most interesting activity in vitro and in vivo, primarily against Gram-positive organisms and was shown to be well absorbed orally.