Regio- and stereochemical control in the photodimerization of methyl 3-(2-furyl)acrylate

The photochemical dimerization of methyl 3-(2-furyl)acrylate in acetonitrile in the presence of benzophenone as triplet sensitizer was reinvestigated in order to understand regio-and stereochemical control. Hplc purification of the dimers and H-1-nmr data allow to correct a wrong structural assignment for a dimer found in the reaction. Regiochemical control can be understood on the of frontier orbitals interaction. Stereochemical control depends on the stability of the dimers. All these data were obtained by the use of the AM1 semiempirical method.