Photocycloaddition of cyclohex-2-enones to alkylidenemalononitriles (1,1-dicyanoalkenes).

5,5-Dimethylcyclohex-2-enone (1a) photocycloadds to ethylidenemalononitrile (2a) to give 5-oxobicyclo[4.2.0]octane-7,7-dicarbonitriles with slight preference, in analogy to results already described for light induced reactions between cyclohexenones and acrylonitrile (AN).