Q77 · CSIR NET Chemistry, December 2011
Paper: CSIR NET December 2011 · Subject: Organic Chemistry · Chapter: Pericyclic Reactions · Topic: Sigmatropic Shifts · Marks: 2 · Difficulty: Medium
The product formed and the process involved in the following reaction are 
(a)
[3,3]-sigmatropic rearrangement
[3,3]-sigmatropic rearrangement(b)
[1,3]-sigmatropic rearrangement
[1,3]-sigmatropic rearrangement(c)
[5,5]-sigmatropic rearrangement
[5,5]-sigmatropic rearrangement(d)
[1,5]-sigmatropic rearrangement
[1,5]-sigmatropic rearrangementAnswer
Answer: C ✓ checked by 4AB · confidence medium
Explanation
The bis-dienyl potassium alkoxide undergoes an anion-accelerated [5,5]-sigmatropic shift. This forms the ring-expanded cyclic enone (c).
Study loop for Pericyclic Reactions