Anisole on reaction with HI forms

Options

A. Phenyl iodide and methyl iodide
B. Phenol and methanol
C. Phenyl iodide and methanol
D. Methyl iodide and phenol

Answer

To solve the question "Anisole on reaction with HI forms," we can follow these steps:

### Step-by-Step Solution:

1. **Identify Anisole**:
Anisole is known as methoxybenzene, which has the structure of a benzene ring with a methoxy group (–OCH3) attached to it.

**Hint**: Remember that anisole is a derivative of benzene with a methoxy group.

2. **Reaction with Hydrogen Iodide (HI)**:
When anisole reacts with hydrogen iodide (HI), the first step involves the protonation of the oxygen atom in the methoxy group by the hydrogen ion (H+) from HI.

**Hint**: Protonation of the oxygen increases the electrophilicity of the molecule.

3. **Formation of Methyl Phenyl Oxonium Ion**:
The protonation leads to the formation of a methyl phenyl oxonium ion, where the oxygen carries a positive charge. This ion is stabilized by resonance with the benzene ring.

**Hint**: Look for resonance structures that can stabilize the positive charge on the oxygen.

4. **Bond Character and Cleavage**:
The bond between the oxygen and the methyl group (–OCH3) is a single bond and can be easily broken, while the bond between the oxygen and the aromatic carbon has partial double bond character due to resonance, making it more difficult to break.

**Hint**: Recognize which bonds are more likely to break based on their character (single vs. partial double bond).

5. **Nucleophilic Attack by Iodide Ion**:
The iodide ion (I-) from HI can now attack the carbon atom of the methyl group (–CH3) because the bond is weaker. This results in the formation of iodomethane (CH3I).

**Hint**: Identify the nucleophile (I-) and where it will attack in the structure.

6. **Formation of Phenol**:
As a result of the bond cleavage, phenol (C6H5OH) is formed from the aromatic part of the molecule.

**Hint**: Remember that the aromatic ring remains intact while the methoxy group is converted.

7. **Final Products**:
The final products of the reaction between anisole and HI are phenol and iodomethane.

**Hint**: Write down the final balanced equation to visualize the products clearly.

### Final Answer:
When anisole reacts with hydrogen iodide (HI), it forms phenol and iodomethane (methyl iodide).