Chapter 24, Problem 24.43P

Interpretation Introduction

(a)

Interpretation:

The given compound can be produced from the two different Diels-alder reactions. The reactants that can be used for each Diels-alder reaction are to be drawn.

Concept introduction:

The Diels–Alder reaction joins a conjugated diene and a dienophile (either an alkene or an alkyne) via the formation of two new $\text{σ}$ bonds. The product is a six-membered ring of carbon atoms.

Substituents on the product are either part of diene or of dienophiles, reactants of Diels-Alder reaction. The C=C bond in the product can be assigned to two different six-membered rings, so the product can be produced from the two different Diels-alder reactions. Standard Diels–Alder reactions are facilitated by electrondonating groups attached to the diene and electron-withdrawing groups attached to the dienophile. Substituents that are cis to each other about the C=C double bond of the dienophile end up cis to each other in the new ring that is produced.

Interpretation Introduction

(b)

Interpretation:

The better route, among two possible Diels-Alders reactions, for the synthesis of the given compound is to be explained.

Concept introduction:

Standard Diels–Alder reactions are facilitated by electron donating groups attached to the diene and electron-withdrawing groups attached to the dienophile. Substituents that are cis to each other about the C=C double bond of the dienophile end up cis to each other in the new ring that is produced.