1 H NMR ( 400 MHz , CDCl 3 ) δ 3 . 99 ( ddd , J = 11 . 8 , 4 . 8 , 1 . 7 Hz , 1 H ) , 3 . 71 - 3 . 80 ( m , 1 H ) , 3 . 35 - 3 . 47 ( m , 2 H ) , 1 . 82 - 1 . 98 ( m , 3 H ) , 1 . 48 ( dddd , J = 12 . 5 , 12 . 4 , 11 . 1 , 4 . 8 Hz , 1 H ) , 1 . 21 ( d , J = 6 . 2 Hz , 3 H ) , 1 . 14 - 1 . 24 ( m , 1 H ) .