InChI=1S/C21H23NO2/c1-21(2,20(23)24)14-7-4-8-15-22(3)16-18-12-9-11-17-10-5-6-13-19(17)18/h4-6,8-13H,15-16H2,1-3H3,(H,23,24)/b8-4+