Chapter 8, Problem 101P

(a)

Interpretation Introduction

Interpretation: The diene and dienophile from the given compounds have to be predicted.

Concept Introduction:

Diels-Alder reaction:

A conjugated diene reacts with a compound containing a carbon-carbon double bond. It is a cycloaddition reaction, where two reactants form a cyclic product.

Conformation of Diene:

S-Cis Conformer: The double bonds are cis about the single bond (s stands for single), in an s-cis conformer.

S-trans Conformer: The double bonds are trans- about the single bond (s stands for single) in an s-trans conformer.

Condition for Diels-Alder reaction:

The conjugate diene must be in an s-cis conformation because when it is in an S-trans conformation, C-1 and C-4 are too far apart to react with the dienophile in a concerted reaction.

(b)

Interpretation Introduction

Interpretation: The diene and dienophile from the given compounds have to be predicted.

Concept Introduction:

Diels-Alder reaction:

A conjugated diene reacts with a compound containing a carbon-carbon double bond.  It is a cycloaddition reaction, where two reactants form a cyclic product.

Conformation of Diene:

S-Cis Conformer: The double bonds are cis about the single bond (s stands for single), in an s-cis conformer.

S-trans Conformer: The double bonds are trans- about the single bond (s stands for single) in an s-trans conformer.

Condition for Diels-Alder reaction:

The conjugate diene must be in an s-cis conformation because when it is in an S-trans conformation, C-1 and C-4 are too far apart to react with the dienophile in a concerted reaction.

(c)

Interpretation Introduction

Interpretation: The diene and dienophile from the given compounds have to be predicted.

Concept Introduction:

Diels-Alder reaction:

A conjugated diene reacts with a compound containing a carbon-carbon double bond.  It is a cycloaddition reaction, where two reactants form a cyclic product.

Conformation of Diene:

S-Cis Conformer: The double bonds are cis about the single bond (s stands for single), in an s-cis conformer.

S-trans Conformer: The double bonds are trans- about the single bond (s stands for single) in an s-trans conformer.

Condition for Diels-Alder reaction:

The conjugate diene must be in an s-cis conformation because when it is in an S-trans conformation, C-1 and C-4 are too far apart to react with the dienophile in a concerted reaction.

(d)

Interpretation Introduction

Interpretation: The diene and dienophile from the given compounds has to be predicted.

Concept Introduction:

Diels-Alder reaction:

A conjugated diene reacts with a compound containing a carbon-carbon double bond.  It is a cycloaddition reaction, where two reactants form a cyclic product.

Conformation of Diene:

S-Cis Conformer: The double bonds are cis about the single bond (s stands for single), in an s-cis conformer.

S-trans Conformer: The double bonds are trans- about the single bond (s stands for single) in an s-trans conformer.

Condition for Diels-Alder reaction:

The conjugate diene must be in an s-cis conformation because when it is in an S-trans conformation, C-1 and C-4 are too far apart to react with the dienophile in a concerted reaction.

(e)

Interpretation Introduction

Interpretation: The diene and dienophile from the given compounds have to be predicted.

Concept Introduction:

Diels-Alder reaction:

A conjugated diene reacts with a compound containing a carbon-carbon double bond.  It is a cycloaddition reaction, where two reactants form a cyclic product.

Conformation of Diene:

S-Cis Conformer: The double bonds are cis about the single bond (s stands for single), in an s-cis conformer.

S-trans Conformer: The double bonds are trans- about the single bond (s stands for single) in an s-trans conformer.

Condition for Diels-Alder reaction:

The conjugate diene must be in an s-cis conformation because when it is in an S-trans conformation, C-1 and C-4 are too far apart to react with the dienophile in a concerted reaction.