Recyclable Mixed Addenda Polyoxometalate: An Efficient Catalyst for the Synthesis of 1, 8-dioxo-octahydroxanthenes in Water

Background: A convenient method for the efficient synthesis of xanthenedione derivatives 4a-r using a dimedone/1,3 cyclohexanedione and various aldehydes in the presence of POMV1 and water as a green solvent is described. Results: This approach is environmentally benign with clean synthetic procedure, short reaction time, easy work-up procedure, excellent yield (80-93%) and regeneration of catalyst which made this protocol efficient and safe. Conclusion: Some novel derivatives were also synthesized using this protocol.