Methanoic acid is manufactued by the reaction of carbon monoxide and methanol in presence of :

${\mathrm{CH}}_3-{\mathrm{CH}}_2-{\mathrm{CH}}_2-\mathrm{COOH}\stackrel{\mathrm{Red} \mathrm{P}+{\mathrm{Br}}_2}{\to } {\mathrm{CH}}_3-{\mathrm{CH}}_2-\underset{\stackrel{|}{\mathrm{Br}}}{\mathrm{CH}}-\mathrm{COOH}$. This reaction is called:

${\mathrm{CH}}_3-\underset{\stackrel{\left|\right|}{\mathrm{O}}}{\mathrm{C}}-{\mathrm{CH}}_2-{\mathrm{CH}}_2-\underset{\stackrel{\left|\right|}{\mathrm{O}}}{\mathrm{C}}-\mathrm{OEt}⟶{\mathrm{CH}}_3-\underset{\stackrel{|}{\mathrm{OH}}}{\mathrm{CH}}-{\mathrm{CH}}_2-{\mathrm{CH}}_2-\underset{\stackrel{\left|\right|}{\mathrm{O}}}{\mathrm{C}}-\mathrm{OEt}$

The above conversion is carried out by