1 H - NMR ( CDCl 3 ) : 7 . 971 ( d , 1 H , J = 8 Hz ) , 7 . 433 ~ 7 . 339 ( m , 5 H ) , 7 . 011 ( d , 1 H , J = 8 . 4 Hz ) , 6 . 924 ( d , 1 H , J = 8 Hz ) , 6 . 865 ( s , 1 H ) , 6 . 538 ( d , 1 H , J = 8 . 4 Hz ) , 6 . 389 ( d , 1 H , J = 10 Hz ) , 5 . 475 ( d , 1 H , J = 10 Hz ) , 5 . 138 ( d , 2 H , J = 8 Hz ) , 4 . 515 ( s , 2 H ) , 3 . 310 ( br , 1 H ) , 2 . 707 ~ 2 . 619 ( m , 2 H ) , 1 . 369 ( s , 6 H ) , 1 . 245 ( t , 3 H , J = 7 . 6 Hz )