9 10-dihydro anthracene nmr July 8, 2019 16 32 64 128 9 10-dimethoxy anthracene Anthracene 9 10-dihydro-2-methyl- 9 10-dihydroanthracene-9 10-α β-succinic anhydride nmr 9 10-dihydroxyanthracene 9 10-dimethylanthracene