A set of regioisomeric pairs of tricyclic hydroquinones, analogues of antitumor 9,10-dihydroxy-4,4-dimethyl-5,8-dihydroanthracen-1(4H)-one (1)
and other derivatives, were synthesized and their regiochemistry and NMR spectra assigned by using 1H-detected one-bond (C[BOND]H) HMQC and
long-range C[BOND]H HMBC, in good agreement with theoretical O3LYP/Alhrichs-pVTZ calculations. The 5-hydroxymethyl derivatives (11, 15, 19)
showed a 3JH, H coupling constant of methylene protons evidencing the presence of a seven-membered intramolecular hydrogen bonded ring, not observed for the 8-hydroxymethyl isomers.
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