1 H - NMR ( CDCl 3 ) : 8 . 057 ( d , 1 H , J = 8 . 8 Hz ) , 7 . 378 ~ 7 . 324 ( m , 5 H ) , 7 . 008 ( d , 1 H , J = 8 Hz ) , 6 . 575 ( dd , 1 H , J = 8 . 8 , 2 Hz ) , 6 . 530 ( d , 1 H , J = 8 Hz ) , 6 . 484 ( d , 1 H , J = 2 . 4 Hz ) , 6 . 380 ( d , 1 H , J = 10 Hz ) , 5 . 461 ( d , 1 H , J = 9 . 6 Hz ) , 5 . 128 ( s , 2 H ) , 5 . 096 ( s , 2 H ) , 4 . 645 ~ 4 . 585 ( m , 1 H ) , 4 . 522 ( d , 2 H , J = 4 Hz ) , 3 . 555 ( br , 1 H ) , 1 . 366 ( s , 6 H ) , 1 . 350 ( s , 3 H ) , 1 . 335 ( s , 3 H )