Abstract
By irradiation, both di(9-anthryl)dimethylsilane and germane afforded a new type of [4 + 2] intramolecular addition product that underwent quantitative cycloreversion by thermolysis. The photoproduct from the former was converted to a novel naphthotriptycene derivative. A phosphorus analogue, di(9-anthryl)phenylphosphine, however did not undergo the reaction. Photochemical reactions of benzyltrimethylsilane and acyloxymetyl(benzyl)dimethylsilanes (RC(O)OCH2SiMe2CH2Ph: R = CH3 and R = t - Bu) are also reported for the first time. The mechanisms of these new photochemical reactions are discussed.