Match each reaction in List-I with the description of its major organic product in List-II. List-I (P) 2,3-Dimethylbutane-2,3-diol heated with dilute…

P: the pinacol rearrangement. Protonation and loss of water gives a tertiary cation, then a methyl shift gives pinacolone, $\mathrm{(CH_3)_3C\!-\!CO\!-\!CH_3}$, a ketone with a quaternary carbon (3). Q: the Hofmann bromamide degradation converts $\mathrm{PhCONH_2}$ into $\mathrm{PhNH_2}$ with loss of the carbonyl carbon as carbonate, a primary aromatic amine (2). R: crossed Cannizzaro reaction. Formaldehyde is the better hydride donor and is oxidised to formate, while benzaldehyde is reduced to benzyl alcohol, $\mathrm{PhCH_2OH}$, a primary alcohol with a benzylic carbinol carbon (5). S: benzilic acid rearrangement of a non-enolisable 1,2-diketone gives $\mathrm{Ph_2C(OH)COOH}$ after acidification, an $\alpha$-hydroxy acid (4). Cyclic amide (1) belongs to a Beckmann product and is not used. The correct code is P→3, Q→2, R→5, S→4.