Synthesis of high-purity dialkyl 2-vinylcyclopropane-1,1- dicarboxylate

摘要

This invention relates to a two-step synthesis of high purity dialkyl 2-vinyl-cyclopropane-1,1-dicarboxylate in which a mixture of trans- and cis-1,4-dihalobutene-2 is first isomerized to essentially trans-1,4- dihalobutene-2 followed immediately by cyclocondensing the resultant trans-1,4-dihalobutene-2 with a malonic ester in the presence of an alcoholic solution of a metallic alkoxide.