Aromatic aldehyde undergoes condensation on heating with an ethanolic solution of KCN. This reaction is called as

Options

A. Perkin reaction
B. Benzoin condensation
C. Claisen condensation
D. Cannizzaro's reaction

Answer

To solve the question regarding the reaction of aromatic aldehyde with an ethanolic solution of KCN, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Reaction**: The question states that an aromatic aldehyde undergoes condensation when heated with an ethanolic solution of KCN (potassium cyanide).

2. **Recognize the Reactants**: The simplest aromatic aldehyde is benzaldehyde (C6H5CHO). The KCN dissociates into K+ and CN- ions in solution. The CN- ion acts as a nucleophile.

3. **Mechanism of the Reaction**:
- The nucleophile (CN-) attacks the electrophilic carbon of the carbonyl group (C=O) in the benzaldehyde. This leads to the formation of a cyanohydrin intermediate.
- The reaction proceeds through the formation of a negatively charged intermediate which can then attack another molecule of benzaldehyde.

4. **Formation of Benzoin**: The reaction continues, leading to the formation of a compound known as benzoin (C6H5C(OH)(C6H5)C=O). This is a condensation reaction where two molecules of benzaldehyde combine to form benzoin.

5. **Naming the Reaction**: The specific reaction that occurs when aromatic aldehydes condense in the presence of KCN is termed "Benzoin Condensation".

### Final Answer:
The reaction is called **Benzoin Condensation**.

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