Control of photoreactions of eight membered ring di- and trienones in a crystalline inclusion complex with optically active 1,6-DI(o-Chlorophenyl)-1,6-diphenylhexa-2,4-diyne-1,6-diol

By complexing with the title host compound, flipping equilibrium of cycloocta-2,4,6-trien-1-one was frozen in one optical conformer as a 2:1 complex, which upon irradiation gave optically active bicyclo [4.2.0] octa-4,7-dien-2-one. Irradiation of a 1:2 complex of cycloocta-2,4-dien-1-one and the same host compound gave an optically active dimer, anti-tricyclo [8.6.0.0^2,9] hexadeca-7, 11-diene-3, 16-dione.