Chapter 11.5, Problem 25P

(a)

Interpretation Introduction

Interpretation:

The compound which undergoes metathesis to form the following compound has to be identified.

Concept introduction:

Alkene Metathesis Or (olefin metathesis)

This breaks the double bond of an alkene and then rejoins the fragments.  When the fragments are joined, the new double bond is formed between two $s{p}^2$ carbons that were not previously bonded. Alkenes also undergoes metathesis.

Terminal alkene gives the best yields of a single alkene product in metathesis because one of the products is ethane, which is equally removed from the reaction mixture, thus shifting the equilibrium in favor of the other new alkene product.

(b)

Interpretation Introduction

Interpretation:

The compound which undergoes metathesis to form the following compound has to be identified.

Concept introduction:

Alkene Metathesis Or (olefin metathesis)

This breaks the double bond of an alkene and then rejoins the fragments.  When the fragments are joined, the new double bond is formed between two $s{p}^2$ carbons that were not previously bonded. Alkenes also undergoes metathesis.

Terminal alkene gives the best yields of a single alkene product in metathesis because one of the products is ethane, which is equally removed from the reaction mixture, thus shifting the equilibrium in favor of the other new alkene product.