8,9-dimethoxy-3,4,5,6-tetrahydrocyclobuta[l]phenanthren-1(2H)-one InChI=1/C18H18O3/c1-20-16-8-12-10-5-3-4-6-11(10)13-7-15(19)18(13)14(12)9-17(16)21-2/h8-9H,3-7H2,1-2H cyclobuta[l]phenanthren-1(2H)-one, 3,4,5,6-tetrahydro-8,9-dimethoxy-