1 H - NMR ( CDCl 3 ) : 8 . 074 ( d , 1 H , J = 8 . 8 Hz ) , 7 . 411 ~ 7 . 340 ( m , 10 H ) , 7 . 011 ( d , 1 H , J = 8 Hz ) , 6 . 682 ( dd , 1 H , J = 8 . 8 , 2 Hz ) , 6 . 592 ( d , 1 H , J = 2 Hz ) , 6 . 536 ( d , 1 H , J = 8 Hz ) , 6 . 384 ( d , 1 H , J = 10 Hz ) , 5 . 468 ( d , 1 H , J = 10 Hz ) , 5 . 130 ( s , 2 H ) , 5 . 106 ( s , 2 H ) , 5 . 073 ( s , 2 H ) , 4 . 522 ( d , 2 H , J = 5 . 2 Hz ) , 3 . 444 ( br , 1 H ) , 1 . 370 ( s , 6 H )