1 H - NMR ( CDCl 3 ) : 8 . 048 ( d , 1 H , J = 8 Hz ) , 7 . 042 ( d , 1 H , J = 8 . 4 Hz ) , 6 . 614 ~ 6 . 548 ( m , 3 H ) , 6 . 449 ( d , 1 H , J = 2 Hz ) , 6 . 067 ~ 5 . 995 ( m , 2 H ) , 5 . 651 ( d , 1 H , J = 10 Hz ) , 5 . 444 ~ 5 . 285 ( m , 4 H ) , 5 . 216 ( s , 2 H ) , 4 . 631 ( d , 2 H , J = 6 . 4 Hz ) , 4 . 596 ~ 4 . 571 ( m , 4 H ) , 3 . 964 ( t , 1 H , J = 6 . 8 Hz ) , 1 . 430 ( s , 6 H )