Synthesis of spirooxindolo/spiroindano nitro pyrrolizidines through regioselective azomethine ylide cycloaddition reaction

摘要

Synthesis of a series of spirooxindolonitro pyrrolizidines and spiroindanonitro pyrrolizidines has been accomplished. The nonstabilized azomethine ylides generated from isatin and ninhydrin with proline reacted with nitro styrenes to regioselectively yield spirocycloadducts.