Identify the following compound from its IR and proton NMR spectra. C5H6O: IR: 3300 (sharp), 2102, 1634 cm–1 NMR: δ 3.10 (1H, d, J = 2 Hz); δ 3.79 (3H, s); δ 4.52 (1H, doublet of doublets, J = 6 Hz and 2 Hz); δ 6.38 (1H, d, J = 6 Hz)