1 H NMR ( CDCl 3 ) δ 8 . 52 ( 1 H , br d , J = 4 . 9 Hz ) , 7 . 56 ( 1 H , br ) , 7 . 46 ( 1 H , dd , J = 7 . 9 , 1 . 8 Hz ) , 7 . 25 ( 1 H , dd , J = 7 . 9 , 4 . 9 Hz ) , 7 . 17 ( 1 H , dd , J = 8 . 6 , 2 . 4 Hz ) , 7 . 10 ( 1 H , dd , J = 8 . 6 , 2 . 4 Hz ) , 5 . 06 ( 1 H , br ) , 4 . 82 - 4 . 62 ( 4 H , m ) , 3 . 98 ( 1 H , d , J = 11 . 0 Hz ) , 3 . 81 ( 1 H , br ) , 3 . 66 ( 1 H , d , J = 11 . 0 Hz ) , 2 . 81 ( 1 H , m ) , 2 . 11 ( 1 H , m ) , 2 . 07 - 1 . 96 ( 2 H , m ) , 1 . 65 ( 1 H , br ) .