Predict the product C in the following series of reactions , `CH_3-COOH overset(PCl_5)rarrAunderset("Anhyd . AlCl_3)overset(C_6H_6)rarrB overset(CH_3MgBr)rarrC`

Options

A. `CH_3-underset(O)underset(||)C-CH_2-CH_3`
B. `CH_3CH(OH)C_6H_5`
C. `CH_3CH(OH)C_2H_5`
D. `(CH_3)_2C(OH)C_6H_5`

Answer

To predict the product C in the given series of reactions, let's break down the steps systematically:

### Step 1: Reaction of Ethanoic Acid with PCl5
The first reaction involves ethanoic acid (CH₃COOH) reacting with phosphorus pentachloride (PCl₅).

- **Reaction**:
\[ \text{CH}_3\text{COOH} \xrightarrow{\text{PCl}_5} \text{CH}_3\text{COCl} + \text{POCl}_3 + \text{HCl} \]
- **Product A**: Ethanoic chloride (acetyl chloride) is formed, which is CH₃COCl.

### Step 2: Friedel-Crafts Acylation with Benzene
Next, we take the product A (ethanoic chloride) and react it with benzene (C₆H₆) in the presence of anhydrous aluminum chloride (AlCl₃).

- **Reaction**:
\[ \text{CH}_3\text{COCl} + \text{C}_6\text{H}_6 \xrightarrow{\text{Anhyd. AlCl}_3} \text{C}_6\text{H}_5\text{COCH}_3 + \text{AlCl}_4^- \]
- **Product B**: Acetophenone (C₆H₅COCH₃) is formed through the Friedel-Crafts acylation reaction.

### Step 3: Reaction of Acetophenone with Grignard Reagent
Now, we take product B (acetophenone) and react it with methylmagnesium bromide (CH₃MgBr).

- **Reaction**:
\[ \text{C}_6\text{H}_5\text{COCH}_3 + \text{CH}_3\text{MgBr} \rightarrow \text{C}_6\text{H}_5\text{C(OMgBr)(CH}_3)_2 \]
- **Mechanism**: The nucleophile (CH₃⁻) from the Grignard reagent attacks the electrophilic carbonyl carbon of acetophenone, forming a tertiary alcohol intermediate.

### Step 4: Hydrolysis of the Intermediate
Finally, we perform hydrolysis on the intermediate formed in the previous step.

- **Reaction**:
\[ \text{C}_6\text{H}_5\text{C(OMgBr)(CH}_3)_2 + \text{H}_2\text{O} \rightarrow \text{C}_6\text{H}_5\text{C(OH)(CH}_3)_2 + \text{MgBrOH} \]
- **Product C**: The final product is a tertiary alcohol, specifically 1,1-dimethyl-2-phenylethanol (C₆H₅C(OH)(CH₃)₂).

### Final Answer
Thus, the product C is:
\[ \text{C}_6\text{H}_5\text{C(OH)(CH}_3)_2 \]

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