In which of the following reaction `CO_(2)` (carbon dioxide) is not released?

Options

A.
B.
C.
D.

Answer

To determine which reaction does not release CO₂, we will analyze each option systematically.

### Step-by-Step Solution:

1. **Analyze Option A**:
- The reaction involves a compound that forms hydrogen bonds.
- As a result of the rearrangement and bond formations, CO₂ is released.
- **Conclusion**: CO₂ is released in Option A.

2. **Analyze Option B**:
- Similar to Option A, this reaction also involves a rearrangement that leads to the formation of CO₂.
- **Conclusion**: CO₂ is released in Option B.

3. **Analyze Option C**:
- This reaction involves a carbohydrate group reacting with sodium bicarbonate.
- The reaction typically results in the formation of a carboxylate and CO₂ gas.
- **Conclusion**: CO₂ is released in Option C.

4. **Analyze Option D**:
- This reaction involves a carbonyl group where the alpha and beta carbons are defined.
- Since there is no keto group on the beta carbon, CO₂ is not released in this reaction.
- **Conclusion**: CO₂ is NOT released in Option D.

### Final Answer:
The reaction in which CO₂ is not released is **Option D**.