1 H NMR ( 399 . 9 MHz , CDCl 3 ) δ 1 . 51 ( 9 H , s ) , 2 . 57 ( 2 H , m ) , 3 . 68 ( 2 H , m ) , 4 . 14 ( 2 H , m ) , 6 . 15 ( 1 H , m ) , 7 . 13 ( 1 H , dd ) , 7 . 33 ( 1 H , s ) , 8 . 20 ( 1 H , d ) , 8 . 34 ( 1 H , d ) , 10 . 29 ( 1 H , s ) ; m / z = 300 [ M + H ] +.