The spirooxindole unit is a privileged heterocyclic motif that forms the core structure of a large family of natural alkaloids and many pharmacological agents with important bioactivity and interesting structural properties.1 On the other hand, 4H-pyrans are interesting compounds in the area of medicinal chemistry due to their extensive range of biological and pharmacological properties.2 In continuation of our previous works for the synthesis of novel heterocyclic compounds,3,4 we report herein an efficient procedure for the synthesis of new spirooxindole derivatives using three-component reaction of isatin derivatives with 1,3- dicarbonyl compounds and pyridinium salts (Scheme 1). The target compounds were obtained in excellent yields under fairly mild reaction conditions.The structure of products was confirmed by IR, 1H and 13C NMR spectroscopy and mass spectrometry.
