Proline-mediated dimerization of cinnamaldehydes via 1,3-dipolar cycloaddition reaction with azomethine ylides. A rapid access to highly functionalized hexahydro-1H-pyrrolizine

1,3-Dipolar cycloaddition reaction of cinnamaldehyde with azomethine ylides generated through decarboxylation of iminium or oxazolidinone intermediate formed by the reaction of l-proline with cinnamaldehydes is reported. The stereoselective reaction provides an efficient access to the highly functionalized hexahydro-1H-pyrrolizine.