Whch of the following gives aldol condensation reaction?

Options

A. `C_(6)H_(5)OH`
B. `C_(6)H_(5)overset(O)overset(||)C-C_(6)H_(5)`
C. `CH_(3)CH_(2)-underset(O)underset(||)O-CH_(3)`
D. `(CH_(3))_(3)C-underset(O)underset(||)C-C(CH_(3))_(3)`

Answer

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

### Step 1: Understand Aldol Condensation
Aldol condensation is a reaction between two carbonyl compounds where one compound forms an enolate ion, which then reacts with another carbonyl compound in the presence of a base (like NaOH) to form a β-hydroxy carbonyl compound. This can further dehydrate to yield an α,β-unsaturated carbonyl compound (conjugated enone).

### Step 2: Identify the Requirement for Aldol Condensation
For a compound to undergo aldol condensation, it must have:
- A carbonyl group (aldehyde or ketone).
- At least one alpha hydrogen (hydrogens attached to the carbon adjacent to the carbonyl carbon).

### Step 3: Analyze Each Compound
Now, let's analyze the given compounds to check for the presence of alpha hydrogens:

1. **Compound 1**: If it is a ketone or aldehyde with no alpha hydrogens, it cannot undergo aldol condensation.
2. **Compound 2**: If it has a carbonyl group and at least one alpha hydrogen, it can undergo aldol condensation.
3. **Compound 3**: Similar to the first, if it lacks alpha hydrogens, it cannot undergo the reaction.

### Step 4: Conclude
After analyzing:
- Identify which compound has the alpha hydrogen.
- The compound that has alpha hydrogens will be the one that can undergo aldol condensation.

### Example Conclusion
If we find that Compound 2 has alpha hydrogens while the others do not, we conclude that **Compound 2** is the one that gives aldol condensation reaction.