Asymmetric synthesis of a structurally and stereochemically complex spirooxindole pyran scaffold through an organocatalytic multicomponent cascade reaction

A novel and convenient organocatalytic tandem reaction has been developed for the asymmetric assembly of saturated aldehydes (or enals), nitroolefins and isatins to produce six-membered oxa-spirooxindole backbones bearing four contiguous stereogenic centers and multiple functional groups with high stereoselectivity.