When benzaldehyde (or any other aromatic aldehyde) is heated with anhydride of an aliphatic acid (containing two `alpha` - hydroge atoms) in presence of its sodium salt, condensation takes place to form an unsaturated carboxylic acid. This reaction is called

Options

A. Perkin reaction
B. Claisen - Schmidt reaction
C. Witting reaction
D. Benzoin condensation

Answer

To solve the question regarding the reaction of benzaldehyde (or any aromatic aldehyde) with an anhydride of an aliphatic acid in the presence of its sodium salt, we need to identify the name of this reaction. Here’s a step-by-step breakdown of the solution:

### Step-by-Step Solution:

1. **Identify the Reactants**:
- We have benzaldehyde (or any aromatic aldehyde, represented as \( \text{ArCHO} \)).
- We are using an anhydride of an aliphatic acid, which contains two alpha-hydrogen atoms (for example, acetic anhydride \( \text{(CH}_3\text{CO)}_2\text{O} \)).
- The presence of sodium salt (e.g., sodium acetate \( \text{CH}_3\text{COONa} \)) is also required.

2. **Understanding the Reaction**:
- When benzaldehyde is heated with the anhydride in the presence of the sodium salt, a condensation reaction occurs.
- This leads to the formation of an unsaturated carboxylic acid.

3. **Formation of the Product**:
- The product formed can be represented as \( \text{ArC}=\text{C(COOH)} \), which is an unsaturated carboxylic acid.
- The reaction involves the formation of a cyclic intermediate and subsequent rearrangements.

4. **Naming the Reaction**:
- This specific reaction is known as the **Parkin Reaction** or **Parkin Condensation**.
- It is characterized by the condensation of an aromatic aldehyde with an anhydride in the presence of its sodium salt to yield an unsaturated carboxylic acid.

5. **Final Answer**:
- Therefore, the name of the reaction is **Parkin Reaction**.