A dipseudoacid, C16H18O6

Pseudoacids, or cyclic oxocarboxylic acids commonly form non-planar, complementary and non-cooperative, dimeric hydrogen-bonds. A dehydration resistant arylpyran dipseudoacid, C16H18O6, has been synthesized and characterized. Crystals of trans-4,4,8,8-tetramethyl-3,7-dihydroxy-1,2,3,4,5,6,7,8-octahydro-2,6-dioxaanthracen-1,5-dione occur in the monoclinic system and form linear hydrogen-bonded chains; it has an elevated melting point without decomposition at 574.6 K.