Compounds D\textbf{D}D and E\textbf{E}E are two structural isomers of C4H8\text{C}_4\text{H}_8C4H8.
Compounds D\textbf{D}D and E\textbf{E}E do not show stereoisomerism.
The table below shows NMR and infrared (IR) spectral data for D\textbf{D}D and E\textbf{E}E.
Number of peaks in 1H NMR spectrumNumber of peaks in 13C NMR spectrumIR peak at 1620–1680 cm−1D11NoE23Yes \begin{array}{|c|c|c|c|} \hline & \text{Number of peaks in } ^1\text{H NMR spectrum} & \text{Number of peaks in } ^{13}\text{C NMR spectrum} & \text{IR peak at } 1620\text{--}1680\text{ cm}^{-1} \\ \hline \textbf{D} & 1 & 1 & \text{No} \\ \hline \textbf{E} & 2 & 3 & \text{Yes} \\ \hline \end{array} DENumber of peaks in 1H NMR spectrum12Number of peaks in 13C NMR spectrum13IR peak at 1620–1680 cm−1NoYesDraw (or describe) the structures of D\textbf{D}D and E\textbf{E}E and explain how the spectral data provides evidence for the structures.
