Which of the following reaction will not proceed via carbanion intermediate ?

Options

A. Perkin reaction
B. cannizaro reaction
C. Claisen condensaation
D. Aldol condensation

Explanation

To determine which of the following reactions does not proceed via a carbanion intermediate, we will analyze each option step by step.

### Step 1: Analyze Perkins Reaction
- **Reaction Type**: Perkins reaction
- **Products**: Cinnamic acid
- **Mechanism**: In this reaction, a carboxylate ion abstracts a proton, leading to the formation of a resonance-stabilized carbanion.
- **Conclusion**: Since a carbanion is formed, this reaction proceeds via a carbanion intermediate.

### Step 2: Analyze Canizzaro Reaction
- **Reaction Type**: Canizzaro reaction
- **Products**: Primary alcohol and carboxylic acid
- **Mechanism**: The reaction involves the attack of hydroxide ion (OH-) on the carbonyl carbon, leading to a hydride shift.
- **Conclusion**: There is no formation of a carbanion in this reaction, making it the correct answer to the question.

### Step 3: Analyze Claisen Reaction
- **Reaction Type**: Claisen reaction
- **Products**: Beta-ketoester or beta-diketone
- **Mechanism**: This reaction involves the formation of a carbanion intermediate as part of the carbon-carbon bond formation process.
- **Conclusion**: Since a carbanion is formed, this reaction proceeds via a carbanion intermediate.

### Step 4: Analyze Aldol Condensation
- **Reaction Type**: Aldol condensation
- **Products**: Beta-hydroxy aldehyde and beta-hydroxy ketone
- **Mechanism**: In this reaction, a carbanion is formed which is essential for the condensation process.
- **Conclusion**: Since a carbanion is formed, this reaction also proceeds via a carbanion intermediate.

### Final Answer
Based on the analysis, the reaction that does not proceed via a carbanion intermediate is the **Canizzaro reaction (Option B)**.

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