Chapter 17, Problem 65IP

Interpretation Introduction

Interpretation:

A mechanism should be proposed for the given transformation.

Concept introduction:

• Sigmatropic rearrangement reaction is a pericyclic reaction of polyenes (π-system), in which one σ-bond is formed and another σ-bond is broken and remaining π-bonds are shifting their positions. Thereby the transition state is cyclic. The mechanism of rearrangement is represented by using curved arrows.
• Cope Rearrangement is a [3,3] sigamatropic rearrangement, in which the π-system having 6 carbons and double bonds are situated at both ends.
• Claisen Rearrangement is a [3,3] sigamatropic rearrangement of allylic vinylic/arylic ethers, in which the ethers will rearranged to carbonyl compound.

To propose: a mechanism for the given transformation.

#assumes the Sigmatropic rearrangements are involved in the given transformation.