M reacts with hot concentrated acidified $\text{KMnO}_4\text{(aq)}$ to form N, $\text{C}_6\text{H}_{10}\text{O}_3$, in reaction 1. Show the structure of N.
N is reduced by $\text{NaBH}_4$ to give 5-hydroxyhexanoic acid in reaction 2. Write an equation for reaction 2 using molecular formulae. In the equation, use $[\text{H}]$ to stand for one hydrogen atom supplied by the reducing agent.
Reaction 2 is a nucleophilic addition. Explain why reaction 2 produces a mixture of two organic compounds.
Draw lactone P, the product of reaction 3.
A student follows the progress of reaction 2 by infrared spectroscopy. Use Table 5.1 to suggest why it is hard to distinguish between N and 5-hydroxyhexanoic acid using infrared spectroscopy.
An unknown lactone Q is examined by mass spectrometry. Table 5.2 gives data from the mass spectrum. Use these data to deduce the structure of Q. Show your working.