1 H - NMR ( 400 MHz , CDCl 3 ) δ 0 . 83 - 1 . 86 ( m , 34 H ) , 3 . 90 ( d , J = 5 . 1 Hz , 2 H ) , 4 . 13 ( t , J = 4 . 8 Hz , 2 H ) , 6 . 96 ( dd , J = 5 . 7 , 1 . 5 Hz , 1 H ) , 7 . 22 - 7 . 24 ( m , 1 H ) , 7 . 77 ( d , J = 6 . 6 Hz , 1 H )