Synthesis of cephalosporin derivatives utilizing the cephem triflate. 1. Introduction of 3-position substituents via a cycloaddition-fragmentation route

Article abstract of DOI:10.1016/0040-4039(96)01714-5

An efficient synthetic route for cephalosporin derivatives with various substituents at the 3-position has been developed. It involves cycloaddition with silyl enol ethers or silylketene acetals followed by fragmentation utilizing the 3-cephem triflate 1 as a starting material.