An oxygen-containing compound gives an M* peak in mass spectroscopy with m/z of 86. The IR shows a broad, strong absorbance at 3400 cm^-1 and a sharp medium absorbance at 1640 cm^-1. The ^1H NMR shows a 3H singlet at delta 1.63, a 3H singlet at delta 1.70, a 1H broad single at delta 3.83. a 2H doublet at delta 4.15 and a 1H triplet at delta 5.70. Draw the compound.