“…134-135°; ultraviolet spectrum: Xmax 333, 460, 490, and 522 µ; n.m.r. spectrum: C-2, C-3, and C-6 methoxyl, 4.04, 4.08, 4.16; C-7 hydroxyl, 6.90 (broad); C-5 and C-8 hydroxyl, 12.16 and 13.30. Methylation of 9 with diazomethane yielded 2,3,6,7tetramethoxynaphthazarin, m.p. 185-186°( lit.8 m.p.…”