CYCLOADDUCTS OF NITROSOBENZENE WITH CYCLIC DIENONES AND DIENOLS

Nitrosobenzene adds regiospecifically to cyclohexadienones 3 and 4, the oxygen of the nitroso group being oriented toward the carbonyl group in the adduct. Addition to eucarvone, a cycloheptadienone, was slower but also regiospecific in the same sense. The hexamethylcyclohexadienone 5, however, gave both regioisomers in approximately equal amounts. Cyclohexadienols 13 and 14 add nitrosobenzene regiospecifically in two senses; the oxygen of the nitroso group is oriented toward the alcohol substituent, and the hydroxyl group is syn to the N-0 bridge. The N-O orientation in addition to dienones and dienols is in accord with expectation from qualitative frontier orbital considerations, and the hydroxyl orientation in the dienol adducts may reflect hydrogen bonding in the transition state. © 1979, American Chemical Society. All rights reserved.