Question

What is the maximum absorption ($\lambda_{max}$) for a homo-annular conjugated diene according to the Woodward-Fieser Rules?

• A. 253 nm
• B. 217 nm
• C. 5 nm
• D. 215 nm

Hint:

Homo-annular diene → Woodward-Fieser $\lambda_{max}$ ≈ 253 nm.

Answer 1

The Correct Option is A

According to Woodward-Fieser Rules, the $\lambda_{max}$ for a homo-annular diene (conjugated double bonds within the same ring) is around 253 nm. Substituents and auxochromes can further shift this value.