In the following reaction

$\mathrm{HCHO}$ and $\mathrm{MeOH}$

$\mathrm{HCHO}$ and $\mathrm{tBuOH}^{2}$

$\mathrm{CH}_{3} \mathrm{CHO}$ and $\mathrm{MeOH}$

$\mathrm{CH}_{3} \mathrm{CHO}$ and ${ }^{t} \mathrm{BuOH}$