Practical synthesis of triptycene trisquinone

A practical approach to the synthesis of triptycene trisquinone (TT) (9,10-dihydro-9,10[1′,2′]-benzenoanthracene-1,4,5,8,13,16-hexone) is reported. To prepare the Diels-Alder adduct, which is a key intermediate that is converted to TT via an oxidation reaction, 1,4,5,8-tetramethoxyanthracene was synthesized via efficient multi-step reactions from a commercial compound. In addition, a two-step reaction involving the reduction of the adduct followed by subsequent oxidation using sodium dichromate was found to be more effective in the synthesis of TT than the direct oxidation of the adduct using ceric ammonium nitrate.