Stereoselective synthesis of cis-1-aryl-2-benzoyl-3,3-dicyanocyclopropanes in the presence of KF center dot 2H(2)O

KF (.) 2H(2)O was found to be a highly efficient base for synthesis of cis-1,2-cyclopropanes with arsonium salt and olefins. The advantages of the process are mild reaction condition, easy workup, excellent yields, and high stereoselectivity.