InChI=1S/C21H24Br4O4/c1-21(2,13-9-15(22)19(16(23)10-13)28-6-4-5-26)14-11-17(24)20(18(25)12-14)29-8-7-27-3/h9-12,26H,4-8H2,1-3H3