Asymmetric Synthesis of New Diastereomerically Pure Spiro Oxindolopyrrolizidines and Oxindolopyrrolidines via Cycloaddition Reactions of Azomethine Ylides and Menthol-Drived Trans-Cinnamic

Document Type: Research Paper

Abstract

Chiral pyrrolidines and pyrrolizidines with spirooxindole ring systems are the central skeletons for numerous alkaloids and pharmacologically important compounds. Gelesmine, pseudotabersonine, formosanine, isoformosanine, morroniside and mitraphylline are some of the alkaloids containing spirooxindole ring systems. Derivatives of spirooxindole find very wide biological applications as anti microbials, anti-inflammatory, antitumourals, antibiotic agents and inhibitors of human NK-1 receptors. An efficient one-pot three-component procedure for the synthesis of newchiral spirooxindolopyrrolidines/pyrrolizidines with highly regio and diastereo-enantio, selective from 1,3-dipolar cycloaddition of azomethineylides and chiral menthol-drived trans-cinnamic are described. The mechanism of the reaction is discussed on the basis of the assignment of the absolute configuration of one of the cycloaddition products, which obtained by single crystal X-ray analysis. The process is occured at reflux temperature in ethanol as green solvent and in the absence of any bidentate chelating Lewis acids.

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