1 H NMR ( CDCl 3 ) δ 8 . 62 ( 1 H , br d , J = 4 . 9 Hz ) , 7 . 55 ( 1 H , d , J = 7 . 9 Hz ) , 7 . 40 ( 1 H , dd , J = 8 . 6 , 6 . 1 Hz ) , 7 . 30 ( 1 H , dd , J = 7 . 9 , 4 . 9 Hz ) , 7 . 21 ( 1 H , br ) , 7 . 19 ( 1 H , dd , J = 8 . 6 , 2 . 4 Hz ) , 7 . 00 ( 1 H , ddd , J = 8 . 6 , 7 . 9 , 1 . 8 Hz ) , 4 . 64 ( 1 H , dd , J = 14 . 7 , 6 . 1 Hz ) , 4 . 57 ( 1 H , dd , J = 14 . 7 , 6 . 1 Hz ) , 4 . 12 ( 1 H , d , J = 15 . 3 Hz ) , 4 . 02 ( 1 H , br ) , 3 . 37 ( 1 H , d , J = 15 . 3 Hz ) , 3 . 11 ( 3 H , s ) , 2 . 79 - 2 . 64 ( 3 H , m ) , 2 . 24 ( 1 H , m ) .