Recueil des Travaux Chimiques des Pays-Bas, 10714, April 1988 ... Photochemical reactivity of a-phenyl P,y-enones. Singlet 1,3-acyl shift, triplet aromatic di-n-methane (DPM) rearrangement and triplet aryl-carbonyl bridging? ... Margareth JCM Koppes, Peter CJ Beentjes and Hans Cerfontain* ... Laboratory of Organic Chemistry, University of Amsterdam, Nieuwe Achtergracht 129, 1018 WS Amsterdam, The Netherlands (Received September 16th. 1987)