Question

How will you convert the following:
(i) Toluene to benzoic acid
(ii) Ethanol to propan-2-ol
(iii) Propanal to 2-hydroxy propanoic acid

Hint:

Oxidation of aldehydes to carboxylic acids can be achieved using strong oxidizing agents like KMnO\(_4\).

Answer 1

(i) Toluene to Benzoic acid:
Toluene can be oxidized to benzoic acid using an oxidizing agent like potassium permanganate (KMnO\(_4\)) or chromic acid (H\(_2\)CrO\(_4\)). The methyl group (-CH\(_3\)) is oxidized to a carboxyl group (-COOH), forming benzoic acid.
(ii) Ethanol to Propan-2-ol:
Ethanol can be converted to propan-2-ol by catalytic hydrogenation using hydrogen (H\(_2\)) in the presence of a catalyst such as palladium (Pd). This reaction adds a hydrogen atom to the ethanol molecule at the second carbon, yielding propan-2-ol.
(iii) Propanal to 2-hydroxy propanoic acid:
Propanal can be oxidized to 2-hydroxy propanoic acid by using an oxidizing agent like potassium permanganate (KMnO\(_4\)). The aldehyde group (-CHO) is oxidized to a carboxyl group (-COOH), and a hydroxyl group (-OH) is introduced at the second carbon via hydrolysis.