Enones with Strained Double Bonds. 9. The 2-Phenylbicyclonon-1-en-3-one System

Article abstract of DOI:10.1021/jo00158a015

Reaction of the bromo ketone 2 with Et3N formed the phenyl-substituted bicyclo<3.3.1>nonenone 1c that was stable when protected from oxygen, water, or other nucleophiles.The enone 1c added MeOH to form the methoxy ketone 4 and reacted slowly with Et3N at 100 deg C to form the reduced ketone 3.The enone 1c reacted slowly with butadiene at 100 deg C to form a mixture of the cycloadducts 13, 15, and 16.Reaction of the enone 1c with oxygen formed a solid mixture of peroxides (presumably 9 and 11).These peroxides reacted with Et3N to form the diol 5 and underwent thermalrearrangement at 50 deg C to form the triketone 6.The reactions with O2 and with butadiene suggest that the enone 1c tends to react as a diradical species.