5,6-dimethoxy-3-methylcyclobuta[a]naphthalene-1,2-dione InChI=1/C15H12O4/c1-7-6-9-8(12-11(7)13(16)14(12)17)4-5-10(18-2)15(9)19-3/h4-6H,1-3H cyclobuta[a]naphthalene-1,2-dione, 5,6-dimethoxy-3-methyl-