Intramolecular polar addition reactions of active methylene moieties to aryl-substituted alkenes via photoinduced electron transfer

The synthesis of cycloalkane derivatives with ring sizes of 5–7 was achieved in moderate yields by photoirradiation of aqueous acetonitrile solutions, containing compounds that consist of active methylene moieties tethered to aryl-substituted alkenes along with sodium hydroxide and 9-cyanophenanthrene. When the substrate contains ethyl cyanoacetate as an asymmetric active methylene moiety, the reaction proceeds in a highly diastereoselective manner.