Unexpected Products in the Synthesis of Tetracyclic Anthrone Systems

An unexpected bis-anthranol (11) was obtained in an attempt to synthesis 1,4-dimethxy anthrone (5a) as a precursor in the total synthesis of tetracyclic anthrone systems (7 and 8) related to anthracyclinones. Oxidative-demethylation of (11) to the corresponding quinone (12) gave the unexpected quinone methide (13). The structure of the latter and the other compounds were confined by spectroscopic measurements.