Chapter 7, Problem 67PP

(a)

Interpretation Introduction

Interpretation:

For the given transformation whether $\text{sodium ethoxide}$ or $\text{potassium tert-butoxide}$ is used as the base is has to be identified.

Concept Introduction:

In an elimination reaction, alkenes are formed when alkyl halides are treated with bases via eliminating one β-proton and one α-halo group of the alkyl halide.

The product of the elimination reaction is depends upon the β-positions of alkyl halide. If the β-positions are identical and the products formed are also identical. If the β-positions are different and the products formed are also different. This means the double bond can form in two different regions so this type of reaction is called regioselective and the products are called as regiochemical outcomes.

The bulkiness of the base controls the regioselectivity in an elimination reaction. According to Zaitsev product rule the more substituted alkene is formed from non-sterically hindered base. According to Hofmann product rule the less substituted alkene is formed from sterically hindered base.

Sodium ethoxide $NaOEt$ is a non-sterically hindered base and $\text{potassium tert-butoxide}$ is a sterically hindered base.

(b)

Interpretation Introduction

Interpretation:

The given transformation whether $\text{sodium ethoxide}$ or $\text{potassium tert-butoxide}$ is used as the base is has to be identified.

Concept Introduction:

In an elimination reaction, alkenes are formed when alkyl halides are treated with bases via eliminating one β-proton and one α-halo group of the alkyl halide.

The product of the elimination reaction is depends upon the β-positions of alkyl halide. If the β-positions are identical and the products formed are also identical. If the β-positions are different and the products formed are also different. This means the double bond can form in two different regions so this type of reaction is called regioselective and the products are called as regiochemical outcomes.

The bulkiness of the base controls the regioselectivity in an elimination reaction. According to Zaitsev product rule the more substituted alkene is formed from non-sterically hindered base. According to Hofmann product rule the less substituted alkene is formed from sterically hindered base.

Sodium ethoxide $NaOEt$ is a non-sterically hindered base and $\text{potassium tert-butoxide}$ is a sterically hindered base.