Novel approach for the conversion of natural Delta(3) cephalosporin derivatives into corresponding Delta(2) cephalosporin derivatives

摘要

A simple one pot synthetic method for the isomerization of cephem double bond from the natural 3-position to 2-cephem positions is affected by silylation. Thus cephalosporin acids are treated with N-trimethylsilylacetamide (MSA) or N,O-bis(trimethylsilyl)acetamide (BSA) and the resulting silyl esters are treated with triethylamine at ambient temperature in the same pot to afford Delta(2)-cephalosporins, which are potentially related compounds in cephalosporin antibacterial compounds.