Spiro indane-1,3-dione pyrrolizidine compounds synthesized by 1,3-dipolar cyclo-addition reaction

摘要

Spiro indane-1,3-dione pyrrolizidine compounds were synthe-sized by the 1,3-dipolar cyclo-addition reaction of ninhydrin, L-proline and two kinds of alkene (chalcone and (E)-β-aryl-nitrostyrene). All these reactions proceeded with good yield and with high regio- and stereoselectivity. It was found that the use of two kinds of alkene lead to different regioselectivity. In the structure of D1 and D2, the electron-withdrawing group (EWG; benzoyl group) is attached to C-3 and the phenyl group is at C-4 of the newly constructed pyrrolidine. In the structure of D3-D7, the EWG (nitro group) is at C-4 and the phenyl group is at C-3 of the newly constructed pyrrolidine.