2,3,6,7-Tetrahydroxy-9,10-dimethyl-9,10-dihydro-9,10-ethanoanthracene bis(1,4-dioxane) solvate.

2,3,6,7-Tetrahydroxy-9,10-dimethyl-9,10-dihydro-9,10-ethanoanthracene crystallizes with 1,4-dioxane to give a bis-solvate, C(18)H(18)O(4).2C(4)H(8)O(2). The bis(catechol) molecule is located on a twofold axis and the two aromatic rings form a dihedral angle of 130.61(4) degree. Hydrogen bonds are formed between the hydroxyl groups and either a neighbouring bis(catechol) molecule or the ether-O atom of a dioxane molecule.