Chapter 13, Problem 40P

Interpretation Introduction

Interpretation:

The structures of the product when 1,3-butadiene reacts with the given dienophiles are to be given.

Concept introduction:

舧 Diels–Alder is a type of organic reaction in which substituted alkene and conjugated diene react to form substituted cyclohexene derivative. It is a single step reaction.

舧 The general reaction of Diels–Alder is as follows:

舧 The Diels–Alder reaction is between a conjugate diene and a reactant containing double bond (dienophile) to form the product and the product is called adduct.

舧 Diels–Alder reactions are highly stereospecific. The configuration of dienophile is retained in the product and the reaction is syn addition.

舧 The dienes react with dienophiles in cis forms rather than trans forms.

舧 Endo and exo refers to the orientation of dienophile and its electron withdrawing group when it reacts with a diene in Diels–Alder reaction.

舧 The reaction with orientation of electron withdrawing group of dienophiles under the $\pi$ orbitals of the diene, is Endo.

舧 The reaction with orientation of electron withdrawing group of dienophiles away from the $\pi$ orbitals of the diene, is Exo

舧 Endo is favored in the transition state of Diels–Alder reaction because of its lower energy.