A Novel, Fast and Efficient One-Pot Four-Component Procedure for Preparation of Some Alkyl Spiro[indeno[1,2-b]quinoxaline-11,3ʹ-pyrrolizine]-2ʹ-carboxylates

In this study we report a novel one-pot reaction which stereoselectively affords alkyl spiro[indeno[1,2-b]quinoxaline-11,3ʹ-pyrrolizine]-2ʹ-carboxylates via the four-component condensation of ninhydrin, phenylenediamines, proline, and acrylic acid derivatives. The reactions were run in ethanol and completed at less than 25 min and the products were obtained in very good yields. The stereochemistry of the products was deduced on the basis of the 1H NOESY and comparison with the related systems