Clemmensen reduction of a ketone is carried out in presence of

Options

A. `H_(2)` with Pd as catalyst
B. glycol with KOH
C. `LiAlH_(4)` in ether
D. `Zn-Hg` with HCl

Answer

**Step-by-Step Solution:**

1. **Understanding Clemmensen Reduction**: Clemmensen reduction is a chemical reaction used to convert ketones or aldehydes into alkanes. This reaction is particularly useful for reducing carbonyl groups.

2. **Identifying the Reagents**: The Clemmensen reduction is carried out in the presence of zinc amalgam (Zn-Hg) and hydrochloric acid (HCl). Zinc amalgam is a mixture of zinc and mercury, which acts as a reducing agent.

3. **Reaction Mechanism**: In the presence of HCl, the zinc amalgam reduces the carbonyl group (C=O) of the ketone or aldehyde. The carbonyl carbon is reduced to a methylene group (C-H2), resulting in the formation of an alkane.

4. **Example Reaction**: For instance, if we take a ketone like acetone (R1C(=O)R2), the reaction with zinc amalgam and HCl will yield propane (R1R2C-H2) as the product.

5. **Oxidation-Reduction Process**: During this reaction, zinc (Zn) acts as a reducing agent. It loses electrons (is oxidized) to form Zn²⁺ ions, while simultaneously reducing the carbonyl compound.

6. **Conclusion**: Therefore, the Clemmensen reduction of a ketone is carried out in the presence of zinc amalgam and hydrochloric acid.

**Final Answer**: The Clemmensen reduction of a ketone is carried out in the presence of zinc amalgam (Zn-Hg) and hydrochloric acid (HCl).

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