Novel Photoreactions of Benzhydrylidenequadricyclane and Quadricyclanone: A New Route to Trimethylenemethane and Oxyallyl Derivatives

Article abstract of DOI:10.1021/jo00005a044

The irradiation of 3-benzhydrylidenequadricyclane (1) generated a trimethylenemethane (TMM) derivative, 3-benzhydrilenebicyclo<3.2.0>hept-6-ene-2,4-diyl (3), which dimerized and could be captured by molecular oxygen and acrylonitrile, but not by furan, methanol, or ethyl vinyl ether.The triplet nature of (3) was confirmed by EPR, emission, and absorption spectra.By contrast, the irradiation of quadricyclanone (2) generated the singlet oxyallyl (OA), 3-oxobicyclo<3.2.0>hept-6-ene-2,4-diyl (4), which could be captured by furan, methanol, and ethyl vinyl ether, but not by molecular oxygen or acrylonitrile, indicating the zwitterionic and electron-accepting nature of 4.