1 H NMR ( 400 MHz , DMSO - d 6 ) δ ppm 1 . 01 - 1 . 15 ( m , 9 H ) , 1 . 21 ( d , J = 7 . 20 Hz , 3 H ) , 2 . 75 　-　 3 . 08 ( m , 3 H ) , 3 . 71 - 3 . 87 ( m , 1 H ) , 4 . 02 - 4 . 13 ( m , 1 H ) , 4 . 22 - 4 . 53 ( m , 3 H ) , 4 . 81 ( s , 　 1 H ) , 5 . 69 - 5 . 86 ( m , 1 H ) , 6 . 04 ( br d , J = 19 . 33 Hz , 4 H ) , 7 . 12 - 7 . 27 ( m , 3 H ) , 7 . 27 - 7 . 44 ( m , 3 H ) , 7 . 81 ( s , 1 H )