Which of the following will undergo aldol condensation ?

Options

A. phenylacetaldehyde
B. formaldehyde
C. benzaldehyde
D. benzophenone

Answer

To determine which of the given compounds will undergo aldol condensation, we need to follow these steps:

### Step 1: Understand the requirements for aldol condensation
Aldol condensation requires:
1. The presence of a carbonyl group (aldehyde or ketone).
2. The presence of at least one alpha hydrogen adjacent to the carbonyl group.

### Step 2: Analyze each compound
We will analyze the compounds one by one to check for the presence of a carbonyl group and alpha hydrogen.

1. **Phenylacetaldehyde**:
- It has a carbonyl group (aldehyde).
- The carbon adjacent to the carbonyl has two alpha hydrogens.
- Therefore, it can undergo aldol condensation.

2. **Formaldehyde**:
- It has a carbonyl group (aldehyde).
- However, it has no alpha hydrogen (the carbon next to the carbonyl is bonded to two hydrogens).
- Therefore, it cannot undergo aldol condensation.

3. **Benzaldehyde**:
- It has a carbonyl group (aldehyde).
- There are no alpha hydrogens present (the carbon adjacent to the carbonyl is bonded to a phenyl group).
- Therefore, it cannot undergo aldol condensation.

4. **Benzophenone**:
- It has a carbonyl group (ketone).
- However, it has no alpha hydrogens (the carbon adjacent to the carbonyl is bonded to two phenyl groups).
- Therefore, it cannot undergo aldol condensation.

### Step 3: Conclusion
Based on the analysis, only **Phenylacetaldehyde** meets the criteria for aldol condensation.

Thus, the answer is **Phenylacetaldehyde**.