Electrochemical transformation of malonate and alkylidenemalonates into 3-substituted cyclopropane-1,1,2,2-tetracarboxylates

Electrolysis of malonate and alkylidenemalonates in an undivided cell in methanol in the presence of sodium bromide or sodium iodide as mediators leads to substituted 1,1,2,2-cyclopropanetetracarboxylates in 80-95% substance and 60-75% current yield.