Abstract
The methyl α-cyanoacrylate-Me^AlCl complex reacts with alkenes to give zwitterion 2. Ring closure on carbon gives the cyclobutane 3 with ~90% retention of alkene stereochemistry, ring closure on oxygen gives dihydropyran 5, and a 1,5-hydrogen shift gives the ene adduct 4. Reaction of the zwitterion 2 with another molecule of methyl α-cyanoacrylate gives 2:1 adducts.