Approaches to the Synthesis of Tetracyclic Quinone System Related to Anthracyclinone

Synthesis of the tetracyclic quinone compound (10) is described. The synthetic route adopted involves: preparation of the precursor 2-(2-methoxy carbonyl benzoyl) 1,4-benzoquinone (7), Diels-Alder reaction of the later with cyclopentadiene, [1,5]-aroyl migration in the resulting adduct (8), and finally ring closure in (9).