Chapter 28, Problem 28.23P

Interpretation Introduction

Interpretation:

An orbital symmetry analysis that a [3.3] sigmatropic reaction that is antrafacial on both components is allowed is to be shown. Would you expect such a reaction to be very common- the statement is to be verified.

Concept introduction:

Sigmatropic reaction can be described as the migration of allylic sigma bond at one end of the π-electron system to the other end of the π-electron system as an uncatalyzed intramolecular reaction. In some cases, Lewis acid catalysts can also be applied. Though, the position of π-bond is changed in Sigmatropic reaction, the total number of π-bonds remain unchanged. The sigma bond can be cleaved at the middle or at the end of the π-system. The formation of sigma bond at 3, 3-position of a 1, 5-diene is called as cope rearrangement.