Aldol condensation is not given by

Options

A. benzophenone
B. acetophenone
C. benzaldehyde
D. propanal

Answer

To determine which substance does not undergo aldol condensation, we need to analyze the given options based on the presence of alpha hydrogens. Aldol condensation typically occurs in aldehydes and ketones that have at least one alpha hydrogen.

### Step-by-Step Solution:

1. **Understanding Aldol Condensation**:
- Aldol condensation is a reaction between aldehydes or ketones that have alpha hydrogens. The presence of at least one alpha hydrogen is essential for the reaction to occur.

2. **Identifying Alpha Hydrogens**:
- Alpha hydrogens are the hydrogen atoms attached to the carbon adjacent to the carbonyl group (C=O). If a compound lacks alpha hydrogens, it cannot undergo aldol condensation.

3. **Analyzing Each Option**:
- **Option A: Benzophenone**
- Structure: C6H5-CO-C6H5
- Benzophenone has no alpha hydrogens because the carbonyl carbon is bonded to two phenyl groups. Therefore, it cannot undergo aldol condensation.

- **Option B: Acetophenone**
- Structure: CH3-CO-C6H5
- Acetophenone has an alpha carbon (the carbon attached to the methyl group) with three alpha hydrogens. Thus, it can undergo aldol condensation.

- **Option C: Benzaldehyde**
- Structure: C6H5-CHO
- Benzaldehyde has no alpha hydrogens because the carbonyl carbon is bonded to a phenyl group. Therefore, it cannot undergo aldol condensation.

- **Option D: Propanal**
- Structure: CH3-CH2-CHO
- Propanal has an alpha carbon with two alpha hydrogens. Thus, it can undergo aldol condensation.

4. **Conclusion**:
- Based on the analysis, both **Option A (Benzophenone)** and **Option C (Benzaldehyde)** do not undergo aldol condensation due to the absence of alpha hydrogens. However, since the question asks for a single option that does not give aldol condensation, we can conclude that **Option A (Benzophenone)** is the most appropriate answer as it is a ketone and does not have any alpha hydrogens.

### Final Answer:
**Option A: Benzophenone** does not undergo aldol condensation.