InChI=1S/C19H21BrO2/c1-22-19(21)17-15-13-11-9-7-5-3-2-4-6-8-10-12-14-16-18-20/h8,10,16,18H,2-4,6,13,15,17H2,1H3/b10-8+,18-16+