In 1985, two researchers at the University of California, Riverside, carried out the reaction given in Fig. P28.51.The equilibrium mixture contained compound A (22%), a single stereoisomer of B (47%), and a single stereoisomer of C (31%).The stereochemistry of compounds B and C at the carbon marked with the asterisk (*) is to be predicted. 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. The formation of sigma bond at 3, 3-position of a 1, 5-diene is called as cope rearrangement. Notably, [3, 3] sigmatropic reaction of allyl vinyl ether is termed as Claisen rearrangement.

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Chapter 28, Problem 28.51AP

Interpretation Introduction

Interpretation:

In 1985, two researchers at the University of California, Riverside, carried out the reaction given in Fig. P28.51.The equilibrium mixture contained compound A (22%), a single stereoisomer of B (47%), and a single stereoisomer of C (31%).The stereochemistry of compounds B and C at the carbon marked with the asterisk (*) is to be predicted.

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. The formation of sigma bond at 3, 3-position of a 1, 5-diene is called as cope rearrangement. Notably, [3, 3] sigmatropic reaction of allyl vinyl ether is termed as Claisen rearrangement.

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