Fill in the table to show what you would observe when an aqueous solution of glycolic acid is added separately to each reagent. If a reaction happens, give the functional group of glycolic acid that causes it.
Draw a structure for $\text{X}$.
Two routes for making glycolic acid are shown: sequence A: $\text{HCHO} \xrightarrow[\text{reaction 1}]{\text{HCN and NaCN}} X \xrightarrow[\text{reaction 2}]{} \text{CH}_2(\text{OH})\text{CO}_2\text{H}$; sequence B: $\text{CH}_3\text{CO}_2\text{H} \xrightarrow[\text{reaction 3}]{\text{Br}_2} \text{CH}_2\text{BrCO}_2\text{H} \xrightarrow[\text{reaction 4}]{} \text{CH}_2(\text{OH})\text{CO}_2\text{H}$.
Name the reagent for reaction 2.
Name the mechanism of reaction 3.
Suggest the essential condition for reaction 3.
Reaction 4 proceeds by an $S_N2$ mechanism. Complete the mechanism diagram for reaction 4. Include all relevant charges, partial charges, curly arrows and lone pairs.
Glycolic acid can also be prepared by reacting glyoxylic acid with $\text{NaBH}_4$.
State the role of $\text{NaBH}_4$ in this reaction.
Write an equation for this reaction using molecular formulae. Use $[\text{H}]$ to represent $\text{NaBH}_4$.
When glycolic acid is heated with a sulfuric acid catalyst, a new compound, $Y$, $\text{C}_4\text{H}_4\text{O}_4$, is produced. The equation for the reaction is given: $2\text{CH}_2(\text{OH})\text{CO}_2\text{H} \rightarrow \text{C}_4\text{H}_4\text{O}_4 + 2\text{H}_2\text{O}$.
The infra-red spectrum of $Y$ is shown. State how this spectrum is different from an infra-red spectrum of glycolic acid. Explain your answer with particular reference to the peaks in the range $1500$-$4000\ \text{cm}^{-1}$.
Suggest a structure for $Y$.