A novel synthesis of diastereomerically pure spiro- oxindolopyrrolizidines and oxindolopyrrolidines via cycloaddition reactions of azomethine ylides

An efficient one-pot three-component procedure for the synthesis of new chiral spiro oxindolopyrrolidines/pyrrolizidines with highly regio- and diastereo-enantio, selective from 1,3-dipolar cycloaddition of azomethine ylides and chiral menthol-drived trans-cinnamic are described. The mechanism of the reaction is discussed on basis of the assignment of the absolute configuration of one of the cycloaddition products, which obtained by single crystal X-ray analysis. The process occurs at reflux temperature in ethanol as green solvent and in the absence of any bidentate chelating Lewis acids. Functionalized pyrrolidines and pyrrolizidines with spirooxindole ring systems are the central skeletons for numerous alkaloids and pharmacologically important compounds.1 Gelesmine, pseudotabersonine, formosanine, isoformosanine, morroniside and mitraphylline are some of the alkaloids containing spirooxindole ring systems.