Phosphomolybdic Acid Catalyzed Synthesis of 1,2,4,5-Tetraoxanes

1,1-Dihydroperoxides were converted into 1,2,4,5-tetraoxanes through condensation with the corresponding ketones in 36-91% yields using phosphomolybdic acid as the catalyst and anhydrous MgSO4 as the water scavenger.