1 H NMR ( 300 MHz , CDCl 3 ) δ 7 . 07 ( d , 1 H , J = 1 Hz ) , 6 . 08 ( dd , 1 H , J = 2 . 7 , 5 . 4 Hz ) , 5 . 85 ( dd , 1 H , J = 2 . 7 , 5 . 7 Hz ) , 4 . 0 ( m , 4 H ) , 3 . 28 ( m , 3 H ) , 2 . 84 ( ddd , 1 H , J = 3 . 6 , 8 . 4 , 12 Hz ) , 1 . 40 ( m , 2 H )