A facile and efficient protocol for the synthesis of 1,8-dioxo-octahydroxanthenes has been developed by one-pot Knoevenagel condensation, Michael addition and cyclodehydration reaction of dimedone (active methylene carbonyl compound) with aromatic aldehydes in the presence of Iron (III) sulfate hydrate as a solid acidic catalyst under solvent-free conditions. Various aromatic aldehydes were uti...