Infer the structure of compound Z (C11H12O4) which has UV-Visible absorptions above 275 nm. Its spectrum shows bands at 3208, 3175, 3100, 2947, 2908, 2847, 2753, 1740, 1730, 1650, 1634, 1590, 1565, 1476, 1455, 1230, and 1105 cm-1. Its 1H-NMR spectrum shows 1.2(d,6H), 3.8(m,1H), 7.3-7.8(ABq,4H), 10.7(s, 1H).