1 H NMR ( 400 MHz , CD 3 OD ) δ 8 . 24 ( d , J = 2 . 2 Hz , 1 H ) , 8 . 04 ( d , J = 2 . 6 Hz , 1 H ) , 8 . 00 ( dd , J = 5 . 1 , 1 . 7 Hz , 1 H ) , 7 . 91 ( dt , J = 9 . 0 , 2 . 0 Hz , 2 H ) , 7 . 71 ( dd , J = 7 . 5 , 1 . 8 Hz , 1 H ) , 7 . 65 ( d , J = 8 . 5 Hz , 1 H ) , 7 . 26 ( d , J = 9 . 1 Hz , 1 H ) , 6 . 70 ( dd , J = 7 . 5 , 5 . 1 Hz , 1 H ) , 4 . 81 ( s , 1 H ) , 3 . 04 ( dd , J = 15 . 6 , 6 . 3 Hz , 4 H ) , 2 . 69 - 2 . 64 ( m , 3 H ) , 2 . 14 ( ddd , J = 51 . 1 , 16 . 4 , 11 . 2 Hz , 4 H ) . LR - MS ( ESI ) m / z 529 ( M + 1 ) .