6659-45-6 Dihydrorotenone NSC53866 [1]Benzopyrano[3,4-b]furo[2,3-h][1]benzopyran-6(6aH)-one, 1,2,12,12a-tetrahydro-8,9-dimethoxy-2-(1-methylethyl)-, [2R-(2.alpha.,6a.alpha.,12a.alpha.)]-