Reaction of 1,1-dichloro-2-(chloromethyl)cyclopropane with some carbanions: a simple synthesis of 1,2-disubstituted methylenecyclopropanes

Abstract

The reaction of cyclopropane 1 with 2-substituted phenylacetonitriles 2a–f carried out in the presence of solid sodium hydroxide and benzyltriethylammonium chloride (TEBAC) as a catalyst in dimethyl sulfoxide, afforded 1,2-disubstituted methylenecyclopropanes 4a–f. The chloride 1 reacted with phenylacetonitrile 2i to give the chain-substituted product 3i, while the reaction of 1 with diphenylacetonitrile 2h gives a mixture of compounds 3h and 4h. The latter reaction carried out in conc. aq. NaOH–cat. TEBAC resulted in the formation of only the chain-substituted product 3h. The nitriles 2 that contain a chiral centre formed a mixture of diastereoisomers of 4.