2,5-cyclohexadien-1-one photochemistry. Reversible type B oxyallyl zwitterion formation from photorearrangements of bicyclo[3.1.0]hex-3-en-2-ones

Article abstract of DOI:10.1021/ja00039a017

Irradiation of 4-cyano-4-[3′-(2-furyl)propyl]-2,5-cyclohexadien-1-one (9a) gave the type B zwitterion-furan cycloadduct 10. Shorter periods of irradiation of 9a enabled isolation of an intermediate, 6-cyano-6-[3′-(2-furyl)propyl]bicyclo[3.1.0)-hex-3-en-2-