1 H NMR ( CDCl 3 ) δ 8 . 53 ( 1 H , m ) , 7 . 56 ( 1 H , d , J = 7 . 9 Hz ) , 7 . 33 - 7 . 28 ( 2 H , m ) , 7 . 11 ( 1 H , dd , J = 9 . 2 , 1 . 8 Hz ) , 7 . 02 ( 1 H , br ) , 5 . 01 ( 1 H , br ) , 4 . 78 ( 1 H , dd , J = 14 . 7 , 5 . 5 Hz ) , 4 . 66 ( 1 H , dd , J = 14 . 7 , 5 . 5 Hz ) , 3 . 97 ( 1 H , d , J = 11 . 6 Hz ) , 3 . 76 ( 1 H , br ) , 3 . 68 ( 1 H , d , J = 11 . 6 Hz ) , 2 . 88 ( 1 H , m ) , 2 . 23 - 1 . 98 ( 3 H , m ) .