Chapter 7, Problem 13E

(a)

Interpretation Introduction

Interpretation: The given molecules need to be labeled as cis, trans or neither. The type of position of H atom circled in the given diagram needs to be described.

Concept Introduction: Chair conformation is the most stable conformation of cyclohexane. It is represented as follows:

  

Here, the substituted groups in the chair conformation are represented as follows:

  

The groups showing in straight upward and downward directions are axial and the groups bend slightly right or left are equatorial.

(b)

Interpretation Introduction

Interpretation: The picture of the molecule needs to be drawn after the chair flip.

Concept Introduction:

The chair conformation of cyclohexane is represented as follows:

  

During the flipping, no bond is break. The numbering in the chair form is represented as follows:

  

During ring flipping, mirror image of the chair conformation is formed.

It is represented as follows:

  

(c)

Interpretation Introduction

Interpretation: In each of the molecule of part (b), the conformation needs to be circled which is lower in potential energy.

Concept Introduction: The molecule with lowest potential energy is most stable. In the chair conformation of the cyclohexane, the stable conformation is when large groups are present in the equatorial positions. The equatorial positions in the chair conformation points away from the ring thus, there is more space.

(d)

Interpretation Introduction

Interpretation: The name of the two molecules drawn in part (b) needs to be determined

Concept Introduction: Chair conformation is the most stable conformation of cyclohexane. It is represented as follows:

  

Here, the substituted groups in the chair conformation are represented as follows:

  

The groups showing in straight upward and downward directions are axial and the groups bend slightly right or left are equatorial.