Claisen condensation is not given by

Options

A.
B.
C.
D.

Explanation

To determine which compound does not undergo Claisen condensation, we need to understand the conditions required for this reaction. The Claisen condensation typically involves the reaction of two esters or an ester and a carbonyl compound (aldehyde or ketone) in the presence of a strong base. A key requirement for this reaction is the presence of alpha hydrogen atoms on at least one of the reactants.

### Step-by-Step Solution:

1. **Identify the Requirements for Claisen Condensation**:
- The reaction requires at least one of the reactants to have alpha hydrogen atoms.
- The presence of a strong base (like sodium ethoxide) is also necessary to deprotonate the alpha hydrogen, allowing for the formation of an enolate ion.

2. **Evaluate the Given Compounds**:
- List the compounds provided in the question and check for the presence of alpha hydrogen atoms.
- Remember that compounds without alpha hydrogen atoms cannot participate in the Claisen condensation.

3. **Analyze Each Compound**:
- **Compound A**: Check if it has alpha hydrogen atoms. If it has none, it cannot undergo Claisen condensation.
- **Compound B**: Check for alpha hydrogen atoms. If it has them, it can participate in the reaction.
- **Compound C**: Similarly, check for alpha hydrogen atoms.
- **Compound D**: Check for alpha hydrogen atoms.

4. **Identify the Compound Without Alpha Hydrogen**:
- After analyzing all the compounds, identify which one lacks alpha hydrogen atoms. This compound will be the one that does not undergo Claisen condensation.

5. **Conclusion**:
- State the compound that does not participate in the Claisen condensation due to the absence of alpha hydrogen atoms.

### Final Answer:
The compound that does not undergo Claisen condensation is the one that lacks alpha hydrogen atoms.

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