Which of the following reagent is used to find out carbon-carbon multiple bonds?

Options

A. Grignard reagent
B. Bayer's reagent
C. Sandmayer's reagent
D. Gattrman reagent

Answer

To determine which reagent is used to identify carbon-carbon multiple bonds, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Carbon-Carbon Multiple Bonds**:
- Carbon-carbon multiple bonds refer to double (C=C) and triple (C≡C) bonds between carbon atoms.

2. **Identifying the Reagents**:
- We need to evaluate the given reagents to see which one is specifically used for detecting these multiple bonds.

3. **Evaluating Bayer's Reagent**:
- Bayer's reagent is potassium permanganate (KMnO4), which is known for its ability to react with alkenes (double bonds) and alkynes (triple bonds).
- When alkenes are treated with cold and dilute KMnO4, they undergo syn-dihydroxylation, resulting in the formation of glycols. This indicates the presence of a double bond.

4. **Evaluating Other Reagents**:
- **Grignard Reagent (R-MgX)**: Used for forming carbon-carbon bonds but not specifically for detecting multiple bonds.
- **Sandmeyer’s Reagent**: Involves diazonium salts and is used for substitution reactions in aromatic compounds, not for detecting multiple bonds.
- **Gatterman Reaction**: Involves the formation of aldehydes from aromatic compounds and does not pertain to multiple bonds.

5. **Conclusion**:
- The reagent specifically used to identify carbon-carbon multiple bonds is Bayer's reagent (KMnO4).

### Final Answer:
The correct reagent used to find out carbon-carbon multiple bonds is **Bayer's reagent (KMnO4)**.

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