1 H NMR ( CDCl 3 ) δ 8 . 59 ( 1 H , ddd , J = 4 . 9 , 1 . 8 , 1 . 2 Hz ) , 7 . 54 ( 1 H , dd , J = 7 . 9 , 1 . 2 Hz ) , 7 . 45 ( 1 H , d , J = 1 . 8 Hz ) , 7 . 36 ( 1 H , d , J = 7 . 9 Hz ) , 7 . 31 - 7 . 23 ( 2 H , m ) , 7 . 18 ( 1 H , br ) , 4 . 80 ( 1 H , ddd , J = 6 . 7 , 6 . 0 , 1 . 2 Hz ) , 4 . 63 ( 1 H , dd , J = 14 . 7 , 6 . 1 Hz ) , 4 . 57 ( 1 H , dd , J = 14 . 7 , 6 . 1 Hz ) , 3 . 79 ( 1 H , br s ) , 2 . 67 ( 1 H , m ) , 2 . 41 - 2 . 25 ( 2 H , m ) , 2 . 15 ( 1 H , m ) .