A novel, self-catalyzed, solvent-free, microwave-enhanced, green, and efficient protocol for the synthesis of 1,8-dioxo-octahydroxanthenes and bis-5,5-dimethyl-1,3-cyclohexanediones by condensing aldo-nitrones (imine oxide) and dimedone (5,5-dimethyl-1,3-cyclohexanedione) under microwave irradiation is disclosed. Product formation (viz. xanthenes and bis-5,5-dimethyl-1,3-cyclohexanediones ) is dependent on reaction conditions. The entire process is green and sustainable in ...