1 H NMR ( 500 MHz , CDCl 3 ) : 7 . 74 - 6 . 49 ( 11 H , m ) , 5 . 87 ( 2 H , s ) , 4 . 05 ( 1 H , d ) , 3 . 32 ( 2 H , m ) , 3 . 49 ( 3 H , s ) , 1 . 50 - 1 . 25 ( 8 H , m ) , 1 . 15 ( 9 H , s ) , 0 . 50 ( 2 H , m ) , 0 . 17 ( 3 H , d )