When phenol is reactes with `CHCI_(3)` and NaOH followed by acidification, salicyladehyde is obtained. Which of the following species are involed in the above-mentioned reaction as intermediates ?

Options

A.
B.
C.
D.

Explanation

To solve the question regarding the reaction of phenol with chloroform (CHCl₃) and sodium hydroxide (NaOH) to form salicylaldehyde, we will analyze the reaction step-by-step and identify the intermediates involved.

### Step-by-Step Solution:

1. **Identify the Reactants**:
- The reactants in this reaction are phenol (C₆H₅OH), chloroform (CHCl₃), and sodium hydroxide (NaOH).

2. **Formation of Dichlorocarbene**:
- When chloroform reacts with sodium hydroxide, a base, it undergoes deprotonation. The hydroxide ion (OH⁻) from NaOH removes a hydrogen atom from chloroform, leading to the formation of an intermediate called dichlorocarbene (CCl₂).
- Reaction:
\[ CHCl₃ + OH⁻ \rightarrow CCl₂ + H₂O + Cl⁻ \]

3. **Electrophilic Attack on Phenol**:
- The dichlorocarbene (CCl₂) acts as an electrophile and attacks the phenoxide ion (the deprotonated form of phenol). The phenoxide ion is formed when phenol loses a hydrogen ion (H⁺).
- The attack occurs at the ortho position of the phenoxide ion, leading to the formation of an intermediate compound.

4. **Formation of Intermediate**:
- The intermediate formed after the attack of dichlorocarbene on the phenoxide ion can be represented as:
\[ C_6H_4(OH)(CCl_2) \]
- This intermediate contains both the hydroxyl group (OH) and the dichlorocarbene moiety.

5. **Rearrangement and Hydrolysis**:
- The intermediate undergoes rearrangement where one of the chlorine atoms is replaced by a hydroxyl group (OH) through hydrolysis, facilitated by the presence of water or hydroxide ions.
- This leads to the formation of salicylaldehyde (ortho-hydroxybenzaldehyde).
- Reaction:
\[ C_6H_4(OH)(CCl_2) \rightarrow C_6H_4(OH)(CHO) + HCl + H_2O \]

6. **Final Product**:
- The final product obtained is salicylaldehyde (C₇H₆O₂), which is ortho-hydroxybenzaldehyde.

### Conclusion:
The intermediates involved in the reaction are:
- **Dichlorocarbene (CCl₂)**
- **Intermediate compound formed after the electrophilic attack**