Which statements about pinacol, $(\mathrm{CH}{}_3){}_2\mathrm{C}(\mathrm{OH})-\mathrm{C}(\mathrm{OH})(\mathrm{CH}{}_3){}_2$, are correct?

1. AIt is obtained by bimolecular reduction of propanone with $\mathrm{Mg}-\mathrm{Hg}$ and water
2. BPeriodic acid $\mathrm{HIO}{}_4$ cleaves it to two moles of propanone
3. CDilute acid converts it into 3,3-dimethylbutan-2-one
4. D$\mathrm{PCC}$ in $\mathrm{CH}{}_2\mathrm{Cl}{}_2$ oxidises it to 2,3-dimethylbutane-2,3-dione