1 H NMR ( 400 MHz , 클로로포름 - d ) δ 7 . 30 ( s , 1 H ) , 7 . 20 ( d , J = 5 . 8 Hz , 1 H ) , 4 . 92 - 4 . 69 ( m , 1 H ) , 4 . 01 ( dd , J = 13 . 6 , 6 . 5 Hz , 2 H ) , 3 . 95 - 3 . 76 ( m , 2 H ) , 1 . 47 ( d , J = 3 . 8 Hz , 9 H ) .