In which of the following all electronic effects namely inductive, mesomeric and hyperconjugative effects are present?

Options

A.
B.
C.
D.

Answer

To determine which of the given options contains all three electronic effects—inductive, mesomeric, and hyperconjugative effects—let's analyze each option step by step.

### Step 1: Understand the Electronic Effects
1. **Inductive Effect (−I or +I)**: This is the permanent effect due to the electronegativity difference between atoms. Electronegative atoms withdraw electrons (−I effect), while alkyl groups donate electrons (+I effect).
2. **Mesomeric Effect (Resonance)**: This effect arises from the delocalization of π electrons across adjacent atoms or groups, leading to resonance structures.
3. **Hyperconjugative Effect**: This involves the interaction of σ bonds (usually C-H) with adjacent empty or partially filled p-orbitals or π bonds, leading to stabilization.

### Step 2: Analyze Each Option
- **Option A**:
- No delocalization of electrons is possible.
- No mesomeric effect.
- No hyperconjugation (no α-hydrogens).
- No inductive effect (no electronegative atoms).
- **Conclusion**: Does not exhibit any of the three effects.

- **Option B**:
- No delocalization of electrons is possible.
- No mesomeric effect.
- No hyperconjugation (no α-hydrogens).
- Inductive effect present due to the presence of electronegative oxygen (−I effect) and CH₃ groups (+I effect).
- **Conclusion**: Lacks mesomeric and hyperconjugative effects.

- **Option C**:
- No delocalization of electrons is possible.
- No mesomeric effect.
- No hyperconjugation (no α-hydrogens).
- Inductive effect present due to the presence of electronegative oxygen (−I effect).
- **Conclusion**: Lacks mesomeric and hyperconjugative effects.

- **Option D**:
- Hyperconjugation is possible due to the presence of α-hydrogens adjacent to a double bond.
- Mesomeric effect is present as electrons can delocalize across the structure.
- Inductive effect is present due to the presence of CH₃ groups (which are +I) and any electronegative atoms.
- **Conclusion**: Exhibits all three effects.

### Final Answer
The correct answer is **Option D**, as it contains all three electronic effects: inductive, mesomeric, and hyperconjugative.