Synthesis and Photochemical Behaviour of 2‐Amino‐1,3‐Cyclohexadienes

The reaction of the 4,4‐dialkylated 2‐cyclohexenones 1 or 2 with a twofold excess of a secondary amine 3 affords the 2‐amino‐1,3‐cyclohexadienes 4 and 5 , respectively. Irradiation (λ ≧ 300 nm) of the morpholino derivative 4a yields a mixture of the isomeric 3‐morpholino‐6‐methyl‐1,3,5‐heptatrienes 6 and 7 , while 5 gives only one corresponding product 8 . The reaction of enone 1 with an equimolar amount of pyrrolidine ( 3c ) affords the bis ‐enamine 9 which is converted to the unsaturated diketone 10 by oxidative hydrolysis.