The predominant chemical process for excited cyclic ketones is the so- called a-cleavage, ie breaking of a CC band with formatian of an acyl - alkyldiradical. Subsequentintramolecularhydrogenatcmtransfergives either aketene or anunsaturated aldehyde (enal). ti the irradiation of the cycloalkanone is performed in an alccholic solvent, the ketene is trap- ped as a carboxylic acid ester and the unsaturated aldebyde affords an ace- tal due to traces of acid present. The ratio of these a-cleavage ...
