1 H NMR ( 400 MHz , CDCl 3 ) δ 9 . 39 ( s , 1 H ) , 8 . 61 ( br d , J = 10 . 2 Hz , 1 H ) , 8 . 04 ( d , J = 8 . 6 Hz , 1 H ) , 8 . 04 ( d , J = 2 . 3 Hz , 1 H ) , 7 . 77 ( dd , J = 9 . 0 , 2 . 3 Hz , 1 H ) , 4 . 40 - 4 . 26 ( m , 1 H ) , 4 . 17 - 4 . 02 ( m , 2 H ) , 3 . 59 ( br ddd , J = 12 , 12 , 1 . 5 Hz , 1 H ) , 3 . 48 ( dd , J = 29 . 1 , 12 . 7 Hz , 1 H ) , 2 . 40 - 2 . 32 ( m , 1 H ) , 2 . 29 - 2 . 16 ( m , 1 H ) .