1,2,3,4,4a,9a-Hexahydro-2-methyl-2,3-epoxyanthracene-9,10-dione 71173-51-8 Anthra(2,3-b)oxirene-3,8-dione, 1a,2,2a,8a,9,9a-hexahydro-1a-methyl-