Photochemistry of some allenic counterparts of cyclohexenones and 2,5-cyclohexadienones

The photochemical rearrangement of a variety of selected ketone analogs with a simple dimethylallenyl moiety is investigated. The systems used in the study are the allenic analogs of 4,4-diphenylcyclohexenone and a similar counterpart of 4,4-diphenyl-2,5-cyclohexadienone. Results show that the photochemical rearrangement of the allenic systems analogs of cyclohexenones and cyclohexadienones exhbit phenyl migration rather than the type A rearrangement.