Chapter 16, Problem 74IP

Interpretation Introduction

Interpretation:

For the given Diels-Alder reaction, the formed product in the two given regiochemical outcomes should be identified.

Concept introduction:

• Cycloaddition reaction is a concerted addition reaction of two reactants to form a ring; in which two π-bonds are converted to two σ-bonds.
• Diels-Alder reaction is a $\left[\text{4+2}\right]\text{ cycloaddition}$ reaction, in which a π-system having four atoms (diene) and a π-system having two atoms (dienophile) are undergoing in cycloaddition reaction and producing a substituted cyclohexene.
• The mechanism of the ring formation in the Diels-Alder reaction is drawn by using three arrows representing the shifting of π-bonds in the two π-systems in a clockwise or counter clockwise fashion, so that the ring formation will take place.
• The electron-withdrawing substituent such as carbonyl groups activates the dienophile for Diels-Alder reaction by making the dienophiles more electron poor so that more susceptible to diene’s attack.
• The electron-donating substituent such as methoxy-groups activates the diene for Diels-Alder reaction by making the diene more electron rich to attack dienophile.

To identify: the product formed from the two given regiochemical outcomes of given reaction.