Study on the Reaction of Electron-deficient Cyclopropane Derivatives with Amines

Reaction of electron deficient cyclopropane derivatives cis-1-methoxycarbonyl-2-aryl-6, 6-dimethyl-5, 7-dioxa-spiro-[2,5]-4,8-octadiones (1a-d) (X = CH₃, H, Cl, NO₂) with anilines (2a-e) (Y = p-CH₃, H, p-Br, p-NO₂, o-CH₃) at room temperature gives N-aryl-trans, trans-α-carboxyl-β-methoxycarbonyl-γ-aryl-γ-butyrolactams (3a-p) in high yields with high stereoselectivity. For example, 1a (X= CH₃) reacts with ammonia 4 or benzyl amine 5 at room temperature to give inner ammonium salt 6 or 7 in the yield of 83% or 97% respectively. The reaction mechanisms for formation of the products are proposed.