Ja. Valderrama et al., REACTION OF SPIROANTHRACENONES WITH DDQ - A ONE-POT SYNTHESIS OF BENZ[A]ANTHRAQUINONES, Journal of the Chemical Society. Perkin transactions. I, (24), 1994, pp. 3521-3523
The dihydroxyspiroanthracenones 7-10 have been prepared from the spiro
naphthalenetrione 2 and treated with DDQ to afford the corresponding a
ngular quinones 12-15.