3,4:8,9-Dimethylenedioxypterocarpan 5H-1,3-dioxolo[4,5-h][1,3]dioxolo[5,6]benzofuro[3,2-c][1]benzopyran, 5a,11a-dihydro- 5a,11a-dihydro-5H-[1,3]dioxolo[4,5-h][1,3]dioxolo[5,6][1]benzofuro[3,2-c]chromene InChI=1/C17H12O6/c1-2-11-17(22-7-19-11)16-8(1)15-10(5-18-16)9-3-13-14(21-6-20-13)4-12(9)23-15/h1-4,10,15H,5-7H