Synthesis from o-(α-methyl-α-1-naphthyl)toluic acid: Newman, J. Am. Chem. Soc. 60, 1141 (1938). From 9,10-dimethyl-9,10-dihydroxy-9,10-dihydro-1,2-benzanthracene: Bachmann, Chemerda, J. Am. Chem. Soc. 60, 1023 (1938). From 9,10-dimethyl-9,10-dimethoxy-9,10-dihydro-1,2-benzanthracene: eidem, ibid. 61, 2358 (1939). From 9-methyl-1,2-benzanthracen-10-one by a Reformatsky reaction: Mikhailov, Chernova J. Gen. Chem. USSR 9, 2171 (1939), C.A. 34, 4068 (1940).