Regio- and stereoselective synthesis of novel trispiropyrrolidine/thiapyrrolizidines using deep eutectic solvent as an efficient reaction media

An efficient synthesis of novel trispiropyrrolidine/thiapyrrolizidines has been reported by the 1,3-dipolar cycloaddition reaction of azomethine ylides with a novel dipolarophile 8,10-bis[(E)arylidene]-3,3-dimethyl-1,5-dioxaspiro[5.5]undecan-9-one using deep eutectic solvent (DES). The DES is cheaper, biodegradable, non-toxic, recyclable and serves as dual role of catalyst as well as solvent. The suitable azomethine ylides were generated 'in situ' from the reaction of substituted isatin/acenaphthenequinone and sarcosine/1,3-thiazolane-4-carboxylic acid. In this protocol generation of one new five-membered pyrrolidine ring with three contiguous stereocenters occurred in a single operation. The stereochemistry of the synthesized compounds including regio- and diastereo was confirmed by spectroscopic techniques and single-crystal X-ray of one representative compound. [GRAPHICS] .