Which of the following reaction cannot be used for the preparation of alkane?

Options

A. Corey-House synthesis
B. Frankland reaction
C. Clemmenson's reduction
D. Aromatization

Answer

To determine which reaction cannot be used for the preparation of alkanes, we will analyze each of the given options: Corey-House synthesis, Franklin reaction, Clemmensen reduction, and Aromatization.

### Step-by-Step Solution:

1. **Corey-House Synthesis**:
- In Corey-House synthesis, a lithium diorganocopper reagent (R₂CuLi) reacts with an alkyl halide (R'X) to form a new carbon-carbon bond, resulting in the formation of an alkane (R-R').
- **Conclusion**: Corey-House synthesis can produce alkanes.

2. **Franklin Reaction**:
- The Franklin reaction involves the reaction of alkyl halides (R-X) with zinc (Zn) to yield alkanes (R-R) and zinc halides (ZnX₂).
- **Conclusion**: Franklin reaction can also produce alkanes.

3. **Clemmensen Reduction**:
- Clemmensen reduction involves the reduction of carbonyl compounds (aldehydes or ketones) to alkanes using zinc amalgam (Zn-Hg) in the presence of hydrochloric acid (HCl).
- The reaction converts the carbonyl group into a saturated alkane.
- **Conclusion**: Clemmensen reduction can produce alkanes.

4. **Aromatization**:
- Aromatization is a reaction where a non-aromatic compound (like cyclohexane) is converted into an aromatic compound (like benzene) through dehydrogenation.
- This process does not yield alkanes; instead, it produces aromatic hydrocarbons, which are unsaturated.
- **Conclusion**: Aromatization does not produce alkanes.

### Final Answer:
The reaction that cannot be used for the preparation of alkanes is **D. Aromatization**.

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