A clean and expedient synthesis of spirooxindoles in aqueous media catalyzed over nanocrystalline MgO

An efficient and eco-friendly method for the synthesis of spirooxindoles with fused tetrahydrochromenes has been demonstrated using basic nanocrystalline MgO catalyst in aqueous condition. The method has been applied for the synthesis of a range of compounds with variable functionalities in excellent yield and selectivity.