The structure that exhibits the following spectral data is \[ \begin{array}{l} \text{IR } (\nu_{\max}): 1740\,\mathrm{cm^{-1}} \\ {}^{1}\mathrm{H}\ \text{NMR}: \delta=0.9(\mathrm{t},3\mathrm{H}), 1.6(\mathrm{sext},2\mathrm{H}), 2.3(\mathrm{t},2\mathrm{H}), 4.6(\mathrm{d},2\mathrm{H}), 5.2(\mathrm{d},1\mathrm{H}), 5.4(\mathrm{d},1\mathrm{H}), 5.9(\mathrm{m},1\mathrm{H})\ \text{ppm} \\ \text{EI-MS } (m/z): 71\ (100\%) \end{array} \]