Use the information provided to demonstrate that a single molecule of X contains five carbon atoms. Show your working.
The mass spectrum shows a peak at $m/e = 57$. Complete the equation to show how X fragments to give this peak. $[\text{C}_5\text{H}_{10}\text{O}_2]^+ \rightarrow \ldots + \ldots$
State the role of TMS and $\text{CDCl}_3$ in NMR spectroscopy. TMS. $\text{CDCl}_3$.
Using both the relative peak areas and their $\delta$ values, consult the Data Booklet to deduce the fragment of the molecule responsible for the peak at $\delta = 2.2$, deduce the fragment of the molecule responsible for the peaks at $\delta = 1.2$ and $\delta = 3.5$, deduce the fragment of the molecule responsible for the peak at $\delta = 4.0$.
When X is reacted with aqueous alkaline iodine, a yellow precipitate is formed. Use this information together with your answers to (c)(i) to suggest a structure for X.
Compound W is an ester with molecular formula $\text{C}_5\text{H}_{10}\text{O}_2$. Its proton NMR spectrum shows just two peaks, whose relative areas are $9 : 1$. Suggest a structure for this ester, W.
Compound V is a carboxylic acid that has a chiral centre. It also has the molecular formula $\text{C}_5\text{H}_{10}\text{O}_2$. Explain what is meant by the term chiral centre.
Suggest a suitable structure for V.