Chapter 4, Problem 67IP

(a)

Interpretation Introduction

Interpretation:

The more stable compound from given compounds cis-1,2-dimethylcyclopropane, trans-1,2-dimethylcyclopropane has to be identified.

Concept introduction:

• Cyclopropane compounds are the smallest cyclic compounds.
• The atoms are very closely located in cyclopropane compounds.
• Every atoms/groups attached to the carbon atoms of cyclopropane are eclipsing in below the plane and above the plane.
• The increasing cost energy order of eclipsed atoms/groups is,

$\text{H/H }\left(\text{4 kJ/mol}\right){\text{ < H/CH}}_{\text{3}}\left(\text{6 kJ/mol}\right){\text{ < CH}}_{\text{3}}{\text{/CH}}_{\text{3}}\left(\text{11 kJ/mol}\right)$

(b)

Interpretation Introduction

Interpretation:

The energy difference between the two compounds has to be predicted.

Concept introduction:

• Cyclopropane compounds are the smallest cyclic compounds.
• The atoms are very closely located in cyclopropane compounds.
• Every atoms/groups attached to the carbon atoms of cyclopropane are eclipsing in below the plane and above the plane.
• The increasing cost energy order of eclipsed atoms/groups is,

$\text{H/H }\left(\text{4 kJ/mol}\right){\text{ < H/CH}}_{\text{3}}\left(\text{6 kJ/mol}\right){\text{ < CH}}_{\text{3}}{\text{/CH}}_{\text{3}}\left(\text{11 kJ/mol}\right)$