A convenient cyclization of dimethyl esters of C6–C9α,α′-dibromoalkanedioic acids to the corresponding dimethyl cycloalk-1-ene-1,2-dicarboxylates

Abstract

Several dimethyl α,α′-dibromoalkanedicarboxylates when treated with sodium hydride in dimethylformamide yield the corresponding dimethyl cycloalk-1-ene-1,2-dicarboxylates: evidence is presented supporting the existence of dimethyl cycloprop-1-ene-1,2-dicarboxylate as an intermediate in the reaction of dimethyl α,α′-dibromoglutarate with potassium t-butoxide.