A method has been developed for the synthesis of substituted β-styrylmalonates by conversion of 2-arylcyclopropane-1,1-dicarboxylates (ACDCs) in the presence of gallium trichloride into the corresponding 1,2-zwitterionic intermediates or (2-arylethylidene)malonates, followed by treatment with pyridine at room temperature leading to an isomerization of the emerging double bond. This method allows one to expand these reactions to include ACDCs with acceptor substituents at the aromatic ring.
Key words
donor-acceptor cyclopropanes - (2-arylethylidene)malonates - β-styrylmalonates - gallium trichloride - isomerization