Which one of the following has inductive, mesomeric and hyperconjugation effect?

Options

A. `CH_(3)Cl`
B. `CH_(3)-CH=CH_(2)`
C. `CH_(3)CH=CH-underset(O)underset(||)(C)-CH_(3)`
D. `CH_(2)=CH-CH=CH_(2)`

Answer

To determine which compound exhibits inductive, mesomeric, and hyperconjugation effects, we will analyze each option step by step.

### Step 1: Understanding the Effects
1. **Inductive Effect (−I)**: This is the permanent effect due to the electronegativity of atoms or groups that withdraw electron density through sigma bonds.
2. **Mesomeric Effect (−M or +M)**: This is the effect due to the delocalization of electrons in a molecule, typically involving π bonds and lone pairs.
3. **Hyperconjugation**: This is the interaction of the electrons in a σ bond (usually C-H or C-C) with an adjacent empty or partially filled p-orbital or π-bonding orbital.

### Step 2: Analyzing Each Option
1. **Option A: CH3Cl**
- **Inductive Effect**: Chlorine is electronegative, so it exhibits a −I effect.
- **Mesomeric Effect**: There is no mesomeric effect because there are no π bonds or lone pairs to delocalize.
- **Hyperconjugation**: There is no hyperconjugation effect as there are no adjacent hydrogen atoms on an α-carbon.
- **Conclusion**: CH3Cl has only the inductive effect.

2. **Option B: CH3-CH=CH2**
- **Inductive Effect**: There is no significant inductive effect present.
- **Mesomeric Effect**: There is no mesomeric effect due to lack of conjugation.
- **Hyperconjugation**: There is hyperconjugation due to the presence of α-hydrogens.
- **Conclusion**: This compound has only hyperconjugation.

3. **Option C: CH3-CH=CH-CO-CH3**
- **Inductive Effect**: The carbonyl oxygen is electronegative, so it exhibits a −I effect.
- **Mesomeric Effect**: The carbonyl group can participate in resonance, showing mesomeric effects.
- **Hyperconjugation**: The α-carbon has three hydrogen atoms, allowing for hyperconjugation.
- **Conclusion**: This compound exhibits all three effects.

4. **Option D: CH3-CH=CH-CH2-COOH**
- **Inductive Effect**: The carboxylic acid group can exhibit a −I effect.
- **Mesomeric Effect**: There is a mesomeric effect due to the carboxylic acid.
- **Hyperconjugation**: There is hyperconjugation due to the presence of α-hydrogens.
- **Conclusion**: This compound has mesomeric and hyperconjugation effects but lacks a significant inductive effect.

### Final Answer
The compound that exhibits inductive, mesomeric, and hyperconjugation effects is **Option C: CH3-CH=CH-CO-CH3**.