Chapter 7.10, Problem 36CC

(a)

Interpretation Introduction

Interpretation:

For the given condition, the reaction that is expected to exhibit a primary isotope effect has to be identified and explained.

Concept Introduction:

Primary Isotope effect: The rate change due to isotopic substitution at a site of bond breaking or bond forming in the rate determining step of a mechanism.

Elimination Reaction: It is just reverse reaction of addition where substituent from the given molecule is removed via $E1$ (the reaction depends only on the substrate involved in the reaction) or $E2$ (the reaction depends on both of the substituents in the reaction) mechanism.

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.

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

(b)

Interpretation Introduction

Interpretation:

For the given condition, the reaction that is expected to exhibit a primary isotope effect has to be identified and explained.

Concept Introduction:

Primary Isotope effect: The rate change due to isotopic substitution at a site of bond breaking or bond forming in the rate determining step of a mechanism.

Elimination Reaction: It is just reverse reaction of addition where substituent from the given molecule is removed via $E1$ (the reaction depends only on the substrate involved in the reaction) or $E2$ (the reaction depends on both of the substituents in the reaction) mechanism.

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.

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