`CH_(3)-CHOoverset(veC CH)rarrCH_(3)CH(OH)CH_(2)CHO`
In the aldol condensation of acetaldehyde represented above, which of the following intermediate species as obtained?

Options

A.
B.
C.
D.

Answer

To solve the problem regarding the aldol condensation of acetaldehyde (CH₃CHO), we will break down the reaction step-by-step and identify the intermediate species formed during the process.

### Step-by-Step Solution:

1. **Identify the Reactant**:
The reactant in this case is acetaldehyde, which has the structure CH₃CHO.

2. **Formation of Enolate Ion**:
In the presence of a dilute base (like OH⁻), the acidic hydrogen from the alpha carbon (the carbon adjacent to the carbonyl group) is abstracted. This results in the formation of an enolate ion.
- The enolate ion can be represented as CH₂=CHO⁻ (with the negative charge on the oxygen).

3. **Nucleophilic Attack**:
The enolate ion acts as a nucleophile and attacks the carbonyl carbon of another acetaldehyde molecule. This results in the formation of a β-hydroxy aldehyde intermediate.
- The structure of this intermediate can be represented as CH₃CH(OH)CH₂CHO.

4. **Dehydration**:
The β-hydroxy aldehyde can undergo dehydration (loss of water) to form an α,β-unsaturated aldehyde. However, the question specifically asks for the intermediate species obtained, which is the β-hydroxy aldehyde.
- The final product after dehydration would be CH₃CH=CHCHO, but we focus on the intermediate.

5. **Conclusion**:
The intermediate species formed during the aldol condensation of acetaldehyde is the β-hydroxy aldehyde, CH₃CH(OH)CH₂CHO.

### Answer:
The intermediate species obtained in the aldol condensation of acetaldehyde is CH₃CH(OH)CH₂CHO.