Provide a structure for the following compound: UV spectrum: ?max = 272 nm (? = 39,500); EI mass spectrum: m/z = 129 (molecular ion and base peak); IR: 2200, 970 cm-1; 1H NMR: ? 5.85 (1H, d, J = 17 Hz); ? 7.35 (1H, d, J = 17 Hz); ? 7.4 (5H, apparent s).