In the given reaction `C_6H_5-overset(O)overset(||)C-CH_3overset((i)C_2H_8MgBr)underset((ii)H_2"O"//H^+)rarr(X)` X will be

Options

A. `1^@` - alcohol
B. `2^@` - alcohol
C. Optically inactive `3^@` - alcohol
D. Optically active `3^@` - alcohol

Answer

To solve the given reaction step by step, we will analyze the reaction between the compound \( C_6H_5COCH_3 \) (acetophenone) and the Grignard reagent \( C_2H_5MgBr \), followed by hydrolysis.

### Step 1: Identify the Reactants
The reactants in the reaction are:
- Acetophenone: \( C_6H_5COCH_3 \)
- Grignard Reagent: \( C_2H_5MgBr \)

### Step 2: Understand the Mechanism of Grignard Reaction
Grignard reagents act as nucleophiles. In this case, the ethyl group \( C_2H_5^- \) from \( C_2H_5MgBr \) will attack the electrophilic carbon of the carbonyl group (C=O) in acetophenone.

### Step 3: Nucleophilic Attack
The carbonyl carbon in acetophenone is electrophilic due to the electronegativity of the oxygen atom. The nucleophile (ethyl group) will attack this carbon, leading to the following intermediate:

\[ C_6H_5C(OH)(C_2H_5)(CH_3)MgBr \]

### Step 4: Formation of Alkoxide Intermediate
Upon the nucleophilic attack, the double bond between carbon and oxygen breaks, resulting in the formation of an alkoxide intermediate:

\[ C_6H_5C(−)(C_2H_5)(CH_3)O^−MgBr \]

### Step 5: Hydrolysis
When the alkoxide intermediate undergoes hydrolysis (reaction with water), the oxygen atom will pick up a proton (H^+) from water, converting the alkoxide into an alcohol:

\[ C_6H_5C(OH)(C_2H_5)(CH_3) + Mg(OH)Br \]

### Step 6: Identify the Product
The final product formed is:

\[ C_6H_5C(OH)(C_2H_5)(CH_3) \]

This compound is a tertiary alcohol because the carbon bearing the hydroxyl group (OH) is attached to three other carbon atoms (one from the phenyl group, one from the ethyl group, and one from the methyl group).

### Step 7: Optical Activity
Since the carbon attached to the hydroxyl group has four different substituents (C6H5, C2H5, CH3, and OH), it is a stereocenter, making the compound optically active.

### Conclusion
The final product \( X \) is an optically active tertiary alcohol.