Amine oxide , when heated , forms alkene. This reaction is called

Options

A. Cope elimination
B. Curtius reaction
C. Hoffmann elimination
D. Mannich reaction

Answer

To solve the question regarding the reaction of amine oxide when heated to form an alkene, we will break down the process step by step.

### Step-by-Step Solution:

1. **Understanding Amine Oxides**:
- Amine oxides are compounds that contain a nitrogen atom bonded to an oxygen atom and typically have at least one hydrogen atom attached to the nitrogen. They can be represented as R1R2R3N→O, where R1, R2, and R3 are organic groups.

**Hint**: Recall the structure of amine oxides and their general formula.

2. **Heating Amine Oxides**:
- When amine oxides are heated, they undergo a specific type of elimination reaction. This reaction involves the removal of a small molecule (like water) and the formation of a double bond (alkene).

**Hint**: Consider what happens to the molecular structure when heat is applied.

3. **Identifying the Reaction Type**:
- The reaction that occurs when amine oxides are heated to form alkenes is known as **Cope Elimination**. This reaction typically involves the formation of a cyclic intermediate and results in the formation of an alkene.

**Hint**: Think about the types of elimination reactions and which ones involve the formation of alkenes.

4. **Mechanism of Cope Elimination**:
- In Cope elimination, the nitrogen atom with a lone pair attacks an electrophilic center, leading to the formation of a cyclic intermediate. Upon heating, this intermediate loses a small molecule (like water), resulting in the formation of an alkene.

**Hint**: Visualize the mechanism of the reaction and the role of the nitrogen atom in facilitating the elimination.

5. **Final Product**:
- The final product of the Cope elimination reaction is an alkene, which is characterized by a double bond between carbon atoms.

**Hint**: Remember that the presence of a double bond is a key feature of alkenes.

### Conclusion:
The reaction of amine oxide when heated to form an alkene is called **Cope Elimination**.