Which one of the following involves nucleophilic addition

Options

A. Kolbe’s reaction of phenol
B. Williamson’s synthesis of ethers
C. Reimer – Tiemann’s reaction of phenol
D. Aldol formation from ethanal

Explanation

To determine which reaction involves nucleophilic addition, we need to understand what nucleophilic addition entails. Nucleophilic addition is a reaction where a nucleophile attacks an electrophilic carbon atom, typically found in carbonyl compounds like aldehydes and ketones.

### Step-by-Step Solution:

1. **Identify the Functional Groups**:
- Look at the options provided in the question. Identify which compounds contain carbonyl groups (C=O), as these are the primary candidates for nucleophilic addition.

2. **Understanding Nucleophiles**:
- Nucleophiles are species that have a pair of electrons to donate. Common nucleophiles in nucleophilic addition reactions include hydride ions (H⁻), alcohols (R-OH), and amines (R-NH₂).

3. **Recognize the Reaction Mechanism**:
- In nucleophilic addition, the nucleophile attacks the electrophilic carbon of the carbonyl group, leading to the formation of a tetrahedral intermediate. This intermediate can then undergo further reactions to yield alcohols or other products.

4. **Evaluate Each Option**:
- For each option, analyze whether it involves a nucleophile attacking a carbonyl carbon.
- If the reaction involves a carbonyl compound being attacked by a nucleophile, then it qualifies as nucleophilic addition.

5. **Select the Correct Answer**:
- Based on the analysis, choose the option that clearly shows a nucleophile attacking a carbonyl compound.

### Conclusion:
The correct answer is the reaction that involves a nucleophile attacking a carbonyl carbon, leading to the formation of a new bond.