Chemical conversion of desacetylcephalothin lactone into desacetylcephalothin. The final link in a total synthesis of cephalosporanic acid derivatives

Desacetylcephalothin lactone was rapidly hydrolyzed to desacetylcephalothin in 10-20% yield in phosphate and borate buffers (pH 6-9, 100°), in borate and carbonate buffers (pH 9-10.8, 25°), and in 0.01 N KOH (25°). In addition, other uncharacterized products were formed. The dosacetylcephalothin formed was isolated as its cephalothin Me ester after esterification and acetylation. These findings establish the final link in the total synthesis of cephalosporins by the lactone route.