1 H - NMR ( CDCl 3 ) : 7 . 698 ( d , 1 H , J = 8 Hz ) , 7 . 630 ( d , 2 H , J = 6 . 4 Hz ) , 7 . 248 ( d , 2 H , J = 8 Hz ) , 7 . 176 ( dd , 1 H , J = 8 , 1 . 6 Hz ) , 7 . 078 ( d , 1 H , J = 8 . 4 Hz ) , 6 . 997 ( d , 1 H , J = 1 . 2 Hz ) , 6 . 601 ( d , 1 H , J = 8 . 4 Hz ) , 6 . 548 ( d , 1 H , J = 9 . 6 Hz ) , 5 . 670 ( d , 1 H , J = 10 Hz ) , 5 . 067 ( s , 2 H ) , 4 . 589 ( d , 2 H , J = 6 . 4 Hz ) , 2 . 949 ( t , 1 H , J = 6 . 4 Hz ) , 2 . 581 ( t , 2 H , J = 7 . 6 Hz ) , 2 . 431 ( s , 3 H ) , 1 . 605 ~ 1 . 549 ( m , 2 H ) , 1 . 430 ( s , 6 H ) , 0 . 899 ( t , 3 H , J = 7 . 2 Hz )