Which of the following compounds is most reactive to an aqueous solution of sodium carbonate ?

Options

A.
B.
C.
D.

Explanation

To determine which compound is most reactive to an aqueous solution of sodium carbonate, we need to analyze the reactivity of each compound in the presence of carbonate ions (CO3^2-), which act as a base in this context. The reactivity will depend on the ability of the compound to stabilize the negative charge that results from the reaction.

### Step-by-Step Solution:

1. **Understand the Reaction Context**:
- Sodium carbonate (Na2CO3) in aqueous solution dissociates to give Na+ ions and carbonate ions (CO3^2-).
- The carbonate ions can act as a base and can abstract protons (H+) from acidic compounds.

2. **Analyze Each Compound**:
- We have four compounds (let's label them A, B, C, and D) to analyze.
- We will look for the presence of acidic protons that can be removed by the carbonate ions.

3. **Compound A**:
- Compound A has a 3-membered ring structure.
- When H+ is removed, a negative charge is generated on the ring.
- However, a 3-membered ring is generally unstable with a negative charge due to angle strain.

4. **Compound B**:
- Compound B has a 5-membered ring structure.
- It can also lose H+ to generate a negative charge.
- The 5-membered ring is more stable than the 3-membered ring but still less stable than larger rings.

5. **Compound C**:
- Compound C has two acidic protons.
- Upon losing H+, it can stabilize the negative charge through resonance.
- This resonance stabilization makes it more reactive than A and B.

6. **Compound D**:
- Compound D has a symmetrical structure with two possible sites for H+ removal.
- It can stabilize the resulting negative charge effectively.
- If it has a conjugated system, it can also stabilize the charge through resonance.

7. **Evaluate Stability**:
- Using Huckel's rule, we can analyze the aromaticity and stability of the resulting anions.
- Compound C, with resonance stabilization, and Compound D, if it forms a stable aromatic system, will be more reactive than A and B.

8. **Conclusion**:
- Among the four compounds, Compound D is likely the most reactive to an aqueous solution of sodium carbonate due to its potential to form a stable aromatic system upon deprotonation.

### Final Answer:
Compound D is the most reactive to an aqueous solution of sodium carbonate.