Q95 · CSIR-NET Chemistry, June 2011

Paper: CSIR-NET June 2011 · Subject: Organic Chemistry · Chapter: Pericyclic Reactions · Topic: Cycloaddition Diels Alder · Marks: 2 · Difficulty: Medium

The concerted photochemical reaction between two olefins leading to a cyclobutane ring is:
(a)$\pi 2 \mathrm{s}+\pi 2 \mathrm{a}$ cycloaddition
(b)$\pi 2s + \pi 2s$ cycloaddition
(c)$\sigma 2 \mathrm{s}+\sigma 2 \mathrm{s}$ cycloaddition
(d)$\pi 2s + \sigma 2a$ cycloaddition
Answer
Answer: B ✓ checked by 4AB · confidence high
Explanation
A photochemical [2+2] cycloaddition of two alkenes is suprafacial on both components: π2s + π2s (b).

Study loop for Pericyclic Reactions

1. Practise the PYQsPrevious-year questions, with answers

· Browse this chapter in the app