See image — GOC and Organic Chemistry Basics Chemistry Question

💡 Solution & Explanation

# Stability Analysis of Conjugated Dienes **Identify the structures:** - **(x)**: Linear conjugated diene (1,3-pentadiene type) — alternating double bonds - **(y)**: Cyclobutene — strained 4-membered ring with one double bond - **(z)**: Cumene/Allene — two adjacent double bonds (non-conjugated) - **(w)**: Conjugated diene with one isolated double bond **Apply stability criteria:** 1. **Conjugation effect**: Conjugated systems are more stable than isolated or cumulated double bonds due to resonance stabilization and orbital overlap. - **(x)** and **(w)** are conjugated → more stable than **(y)** and **(z)** 2. **Ring strain**: Cyclobutene **(y)** has severe ring strain from the 4-membered ring, making it the **least stable**. 3. **Cumulative instability**: Allenes/cumenes **(z)** with adjacent double bonds lack conjugation and are unstable due to orthogonal $\pi$ orbitals. 4. **Conjugation comparison**: **(x)** has extended linear conjugation with better orbital overlap than **(w)** which has limited conjugation points. **Stability order:** $$\boxed{x > w > z > y}$$ **Answer: (C)** ✓ The conjugated diene (x) is most stable, followed by the partially conjugated system (w), then the unstable cumene (z), and finally the highly strained cyclobutene (y) is least stable.