Synthesis of 7-acylamidodesacetoxycephalosporanic acids and corresponding pivaloyloxymethyl esters. Chemical and microbiological properties.

A series of 7-acylamidodesacetoxycephalosporanic acids and analogous pivaloyloxymethyl esters have been prepared and tested in vitro for antibacterial activity. Those acids which exhibited a significant in vitro activity, were also studied in vivo and compared with the corresponding esters. Experiments performed on laboratory animals showed that, after oral administration, the esters were absorbed more efficiently than the corresponding acids.