3-[(2R,3R)-1-dimethylamino-2-methylpentan-3-yl]phenol 3-[(1R,2R)-3-dimethylamino-1-ethyl-2-methyl-propyl]phenol 3-[(1R,2R)-3-dimethylamino-1-ethyl-2-methylpropyl]phenol 3-[(2R,3R)-1-dimethylamino-2-methyl-pentan-3-yl]phenol D06007 Tapentadol Tapentadol (USAN)