1 H NMR ( 400 MHz , CDCl 3 ) δ 9 . 28 ( s , 1 H ) , 8 . 73 ( s , 1 H ) , 8 . 67 ( s , 1 H ) , 8 . 59 ( s , 1 H ) , 8 . 24 ( d , J = 9 . 0 Hz , 1 H ) , 7 . 66 ( dd , J = 8 . 9 , 2 . 1 Hz , 1 H ) , 5 . 30 ( br s , 1 H ) , 5 . 27 ( s , 2 H ) , 4 . 73 ( s , 2 H ) , 4 . 34 ( dd , J = 12 . 0 , 5 . 1 Hz , 1 H ) , 3 . 73 ( br s , 2 H ) , 2 . 75 ( br s , 1 H ) , 2 . 48 ( br s , 1 H ) , 2 . 17 ( s , 3 H ) , 1 . 85 ( br s , 1 H ) , 1 . 74 ( br s , 1 H ) , 1 . 38 ( d , J = 6 . 1 Hz , 3 H ) .