When acetaldehyde is treated with Grignard reagent, followed by hydrolysis the product formed is :

Options

A. Primary alcohol
B. Secondary alcohol
C. Carboxylic acid
D. Tertiary alcohol

Answer

To solve the problem of what product is formed when acetaldehyde is treated with a Grignard reagent followed by hydrolysis, we can break it down into a series of steps.

### Step-by-Step Solution:

1. **Identify the Reactants**:
- Acetaldehyde has the formula CH₃CHO.
- The Grignard reagent can be represented as R-MgBr, where R is an alkyl group.

2. **Understand the Reaction Mechanism**:
- Grignard reagents act as nucleophiles. The alkyl group (R⁻) from the Grignard reagent will attack the electrophilic carbon atom of the carbonyl group (C=O) in acetaldehyde.

3. **Nucleophilic Attack**:
- The nucleophilic alkyl group (R⁻) attacks the carbon atom of the carbonyl group in acetaldehyde, leading to the formation of a tetrahedral intermediate. This results in the following structure:
\[ CH₃C(OH)(R)MgBr \]
- Here, the oxygen atom of the carbonyl group now carries a negative charge (O⁻).

4. **Formation of Alkoxide**:
- The tetrahedral intermediate can be represented as:
\[ CH₃C(OH)(R)MgBr \]
- The magnesium bromide (MgBr⁺) interacts with the negatively charged oxygen, forming an alkoxide:
\[ CH₃C(OR)(MgBr) \]

5. **Hydrolysis**:
- Upon hydrolysis (addition of water), the alkoxide reacts with water. The magnesium bromide part is replaced by a hydroxyl group (OH):
\[ CH₃C(OH)(R) + MgBrOH \]
- This results in the formation of a secondary alcohol.

6. **Final Product**:
- The final product is a secondary alcohol where the structure can be represented as:
\[ CH₃C(OH)R \]
- The product is a secondary alcohol because the carbon atom to which the hydroxyl group is attached is connected to two other carbon atoms (the methyl group and the alkyl group from the Grignard reagent).

### Conclusion:
The product formed when acetaldehyde is treated with a Grignard reagent followed by hydrolysis is a secondary alcohol.