AbstractIn the presence of KF·2H2O, furoylmethyltriphenylarsonium bromide (1a) or thienoylmethyltriphenylarsonium bromide (1b) reacted with 2‐[(un)substituted benzylidene]malononitrile (2) in chloroform at room temperature to give trans‐3,3‐dicyano‐1‐furoyl‐2‐[(un)substituted phenyl]cyclopropane (3a) or trans‐3,3‐dicyano‐1‐thienoyl‐2‐[(un)substituted phenyl]cyclopropane (3b) respectively in good yield with high stereoselectivity. The structures of product 3 were confirmed by IR, MS, 1H NMR, 1H‐1H COSY and microanalysis. The relative configuration of product 3 was determined by 1H‐1H NOESY technique. The mechanism for the formation of product 3 was also proposed.