A set of reactions yielded a product (D):
`CH_(3)COOHoverset(SOCl_(2))to(A)underset(anhyd.AlCl_(3))overset("Benzene")to(B)overset(HCN)to(C )overset(HOH)to(D)`
The structure of (D) would be:

Options

A.
B.
C.
D.

Answer

To solve the problem step by step, we will analyze each reaction and determine the structure of the final product (D).

### Step 1: Reaction of Acetic Acid with SOCl2
- **Starting Compound**: Acetic Acid (CH₃COOH)
- **Reaction**: Acetic acid reacts with thionyl chloride (SOCl₂).
- **Product**: The hydroxyl group (-OH) in acetic acid is replaced by a chlorine atom (-Cl), forming acetyl chloride (CH₃C(=O)Cl).

**Structure**:
- CH₃C(=O)Cl (Acetyl chloride)

### Step 2: Friedel-Crafts Acylation with Benzene
- **Starting Compound**: Acetyl Chloride (CH₃C(=O)Cl)
- **Reagent**: Benzene (C₆H₆) and anhydrous aluminum chloride (AlCl₃).
- **Reaction**: This is a Friedel-Crafts acylation reaction where the acetyl group is introduced to the benzene ring.
- **Product**: The product formed is acetophenone (C₆H₅C(=O)CH₃).

**Structure**:
- C₆H₅C(=O)CH₃ (Acetophenone)

### Step 3: Reaction of Acetophenone with HCN
- **Starting Compound**: Acetophenone (C₆H₅C(=O)CH₃)
- **Reagent**: Hydrogen cyanide (HCN).
- **Reaction**: The carbonyl group (C=O) in acetophenone reacts with HCN, resulting in the addition of a cyanohydrin.
- **Product**: The product will have a hydroxyl group (-OH) and a cyano group (-CN) attached to the same carbon.

**Structure**:
- C₆H₅C(OH)(CN)CH₃

### Step 4: Hydrolysis of the Cyanohydrin
- **Starting Compound**: The cyanohydrin formed in the previous step.
- **Reagent**: Water (H₂O).
- **Reaction**: The cyano group (-CN) is hydrolyzed to a carboxylic acid (-COOH).
- **Product**: The final product will have two carboxylic acid groups, one from the hydrolysis of the cyano group and one from the original acetophenone structure.

**Final Structure (D)**:
- C₆H₅C(OH)(COOH)CH₃

### Final Answer
The structure of product (D) is:
- **C₆H₅C(OH)(COOH)CH₃**