Fill in the blanks with appropriate structure of reaction products in the following trasformation:
`HOOC-C_(6)H_(4)-CH_(2)-C_(6)H_(5)overset(SOCl_(2))rarrAunderset(AlCl_(3))overset("anlydrous")rarrBunderset(HCl)overset(Zn-Hg)rarrC`

Answer

To solve the transformation reaction step by step, we will identify the structure of the reactant and the products at each stage of the reaction.

### Step 1: Identify the Reactant
The given reactant is:
\[ \text{HOOC-C}_6\text{H}_4-\text{CH}_2-\text{C}_6\text{H}_5 \]
This structure can be represented as:
- A benzoic acid derivative (due to the -COOH group)
- A benzyl group (-CH2-C6H5) attached to the aromatic ring.

### Step 2: Reaction with SOCl2
When the reactant is treated with thionyl chloride (SOCl2), the carboxylic acid (-COOH) group is converted into an acyl chloride (-COCl) through the following reaction:
\[ \text{HOOC-C}_6\text{H}_4-\text{CH}_2-\text{C}_6\text{H}_5 \xrightarrow{\text{SOCl}_2} \text{Cl-C}_6\text{H}_4-\text{CH}_2-\text{C}_6\text{H}_5 + \text{SO}_2 + \text{HCl} \]
The product A is:
\[ \text{Cl-C}_6\text{H}_4-\text{CH}_2-\text{C}_6\text{H}_5 \]

### Step 3: Reaction with AlCl3
Next, the acyl chloride product (A) undergoes Friedel-Crafts acylation when treated with anhydrous aluminum chloride (AlCl3). This reaction leads to the formation of a ketone via intramolecular acylation:
\[ \text{Cl-C}_6\text{H}_4-\text{CH}_2-\text{C}_6\text{H}_5 \xrightarrow{\text{AlCl}_3} \text{C}_6\text{H}_4\text{(C=O)-CH}_2-\text{C}_6\text{H}_5 + \text{HCl} \]
The product B is:
\[ \text{C}_6\text{H}_4\text{(C=O)-CH}_2-\text{C}_6\text{H}_5 \]

### Step 4: Clemmensen Reduction with Zn-Hg and HCl
Finally, the ketone product (B) undergoes Clemmensen reduction in the presence of zinc amalgam (Zn-Hg) and hydrochloric acid (HCl), which reduces the carbonyl group (C=O) to a methylene group (CH2):
\[ \text{C}_6\text{H}_4\text{(C=O)-CH}_2-\text{C}_6\text{H}_5 \xrightarrow{\text{Zn-Hg, HCl}} \text{C}_6\text{H}_4\text{(CH}_2\text{)-CH}_2-\text{C}_6\text{H}_5 \]
The final product C is:
\[ \text{C}_6\text{H}_4\text{(CH}_2\text{)-CH}_2-\text{C}_6\text{H}_5 \]

### Summary of the Products
- **Product A**: \[ \text{Cl-C}_6\text{H}_4-\text{CH}_2-\text{C}_6\text{H}_5 \]
- **Product B**: \[ \text{C}_6\text{H}_4\text{(C=O)-CH}_2-\text{C}_6\text{H}_5 \]
- **Product C**: \[ \text{C}_6\text{H}_4\text{(CH}_2\text{)-CH}_2-\text{C}_6\text{H}_5 \]