Substitution effects on regioselective cyclizations of 1,5- and 2,4-diphenyl-1,5-hexadiene cation radicals generated by the electron-transfer photosensitizations

Article abstract of DOI:10.1016/S0040-4039(00)77604-0

The 9,10-dicyanoanthracene (DCA)-sensitized electron-transfer photoreactions of E- and Z-1,5-diphenyl-1,5-hexadienes (E-2 and Z-2) gave a mixture of endo- and exo-1,5-diphenylbicyclo [2.1.1]hexanes (endo-3 and exo-3) while 2,4-diphenyl-1,5-hexadiene (1) underwent the Cope rearrangements to E-2, showing significant substitution effects on cyclization of 1,5-hexadiene cation radicals.