1 H NMR ( 399 . 9 MHz , CDCl 3 ) δ 1 . 18 ( 9 H , s ) , 1 . 24 - 1 . 35 ( 2 H , m ) , 1 . 79 - 1 . 84 ( 1 H , m ) , 1 . 92 ( 2 H , d ) , 2 . 98 - 3 . 05 ( 2 H , m ) , 3 . 23 ( 2 H , d ) , 4 . 25 ( 2 H , d ) , 7 . 09 ( 1 H , d ) , 7 . 89 ( 1 H , d ) ; m / z = 358 [ M + H ] +.