Cyclohexanone on being heated with NaOH solution forms.

Options

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Answer

To solve the question regarding the reaction of cyclohexanone when heated with sodium hydroxide solution, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Reactants**:
- The reactant is cyclohexanone, which has the structure of a six-membered ring with a carbonyl group (C=O) attached to one of the carbon atoms.

2. **Understand the Role of Sodium Hydroxide (NaOH)**:
- Sodium hydroxide is a strong base and can abstract protons (H⁺) from compounds. In this case, it will abstract an alpha-hydrogen from cyclohexanone.

3. **Identify Alpha-Hydrogens**:
- Cyclohexanone has two alpha-hydrogens on the carbon atoms adjacent to the carbonyl carbon. These hydrogens are acidic and can be removed by the base.

4. **Aldol Condensation Mechanism**:
- The reaction of cyclohexanone with NaOH leads to an aldol condensation. The base abstracts an alpha-hydrogen, forming an enolate ion. This enolate can then attack the carbonyl carbon of another cyclohexanone molecule.

5. **Formation of Beta-Hydroxy Carbonyl Compound**:
- The nucleophilic attack results in the formation of a beta-hydroxy carbonyl compound (an aldol). This compound has both a hydroxyl group (-OH) and a carbonyl group (C=O) in its structure.

6. **Dehydration to Form Alpha, Beta-Unsaturated Carbonyl Compound**:
- Upon heating, the beta-hydroxy carbonyl compound undergoes dehydration (loss of water) to form an alpha, beta-unsaturated carbonyl compound. This compound has a double bond between the alpha and beta carbons.

7. **Final Product**:
- The final product of the reaction is an alpha, beta-unsaturated carbonyl compound derived from cyclohexanone.

### Conclusion:
The product formed when cyclohexanone is heated with sodium hydroxide solution is an **alpha, beta-unsaturated carbonyl compound**.