Final answer:
When cinnamaldehyde reacts with KMnO4, the permanganate ion acts as an oxidizing agent, leading to the formation of carboxylic acids.
Step-by-step explanation:
When cinnamaldehyde reacts with KMnO4, the permanganate ion acts as an oxidizing agent. It reacts with cinnamaldehyde by transferring oxygen atoms to the organic compound, resulting in the formation of carboxylic acids. The primary reaction can be represented by the equation:
2KMnO4 + 3C6H5CH=CHCHO → 2MnO2 + 3C6H5COOH + KOH
Secondary reactions may occur, such as the oxidation of a primary alcohol to an aldehyde, or the oxidation of an aldehyde to a carboxylic acid, depending on the conditions and the reaction time.