Which of the following alkenes is the most stable ?

Options

A.
B.
C.
D.

Explanation

To determine which of the given alkenes is the most stable, we will analyze the stability based on the concept of hyperconjugation and the number of alpha hydrogens attached to the alkene.

### Step-by-Step Solution:

1. **Understanding Hyperconjugation**:
- Hyperconjugation is the interaction between the electrons in a σ-bond (usually C-H or C-C) and an adjacent empty or partially filled p-orbital or π-bond. More hyperconjugation leads to greater stability of the alkene.

2. **Identifying Alpha Carbons**:
- Alpha carbons are the carbons that are directly attached to the double bond (alkene). The stability of alkenes increases with the number of alpha hydrogens on these alpha carbons.

3. **Analyzing Each Option**:
- **Option 1**:
- Alkene structure has 1 alpha carbon with 1 hydrogen.
- Total alpha hydrogens = 1.

- **Option 2**:
- Alkene structure has 2 alpha carbons, each with 2 hydrogens.
- Total alpha hydrogens = 2 + 2 = 4.

- **Option 3**:
- Alkene structure has 1 alpha carbon with 1 hydrogen.
- Total alpha hydrogens = 1.

- **Option 4**:
- Alkene structure has 3 alpha carbons, each with 3 hydrogens.
- Total alpha hydrogens = 3 + 3 + 2 = 8.

4. **Comparing Stability**:
- Based on the total number of alpha hydrogens:
- Option 1: 1 alpha hydrogen
- Option 2: 4 alpha hydrogens
- Option 3: 1 alpha hydrogen
- Option 4: 8 alpha hydrogens
- The more alpha hydrogens present, the more hyperconjugation and thus greater stability of the alkene.

5. **Conclusion**:
- Option 4 has the highest number of alpha hydrogens (8), making it the most stable alkene due to the maximum hyperconjugation effect.

### Final Answer:
The most stable alkene is **Option 4**.

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