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

On the basis of the reaction of β-styrylmalonates with furfural derivatives in the presence of GaCl3 that occurs with opening of the furan ring, an efficient diastereoselective method for the synthesis of trisubstituted cyclopentenones containing a 1,4-diketone moiety was developed. The regularities of the reaction were studied, and a number of chemical reactions of the resulting substrates were carried out. A mechanism for the formation of substituted (4-oxo-2-arylcyclopent-2-enyl)­malonates was suggested.

A new type of dimerization of dimethyl (β-styryl)malonates in the presence of TiCl4 accompanied by elimination of a methanol molecule was discovered. Selective methods for the synthesis of substituted trimethyl 4-hydroxy-[1,1′-biaryl]-3,3,5(2H)-tricarboxylates and trimethyl 7-hydroxy-9,10-dihydro-5,9-methanobenzo[8]annulene-6,8,8(5H)-tricarboxylates were developed. The regularities of the occurring processes were determined and a similar reaction of β-styrylmalonate with benzylidenemalonate in the presence of TiCl4 was performed in the scope of the suggested mechanism.