Chapter 7.11, Problem 37PTS

(a)

Interpretation Introduction

Interpretation:

The major and minor products should be drawn for the given each elimination reactions.

Concept Introduction:

• ${\text{S}}_{\text{N}}2$Reaction: It is a nucleophilic substitution reaction in which the rate determining step depends on both of the molecules involved. The bond making and the bond breaking process happens simultaneously in this reaction.
• Structure of the substrate plays major role in the reactivity of ${\text{S}}_{\text{N}}2$ reaction. If the substrate is more substituted then the rate of the reaction will becomes slower. Since the mechanism of ${\text{S}}_{\text{N}}2$ reaction proceeds through backside attack on the substrate, it depends on steric factor that if more groups attached near the leaving group the reactivity becomes slower.
• Reaction mechanism path is depending on both natures of substrate and reagent.
• If the reagent is strong base as well as strong nucleophile and the substrate is primary alkyl halide then the reaction follows ${\text{S}}_{\text{N}}\text{2}$ mechanism if the substrate is secondary alkyl halide then the reaction follows E2 mechanism. For ${\text{S}}_{\text{N}}\text{2}$ mechanism reagent should be strong nucleophile.

(b)

Interpretation Introduction

Interpretation:

The major and minor products should be drawn for the given elimination reaction.

Concept Introduction:

• Elimination reaction: In elimination reaction, two substituents are removed from the substrate to give the product in presence of base. Elimination reactions are two types, $E1$ and $E2$.
• $E1$ reaction: elimination follows stepwise mechanism.
• $E2$ reaction: elimination follows concerted pathway of mechanism.
• Elimination of compound in presence of bulky base leads to less substituted alkene, in presence of strong base (not bulky) leads to more substituted alkene.

(c)

Interpretation Introduction

Interpretation:

Major and minor product should be drawn for the given substrates during E2 elimination reaction.

Concept Introduction:

• Elimination reaction: In elimination reaction, two substituents are removed from the substrate to give the product in presence of base. Elimination reactions are two types, $E1$ and $E2$.
• $E1$ reaction: elimination follows stepwise mechanism.
• $E2$ reaction: elimination follows concerted pathway of mechanism.
• Elimination of compound in presence of bulky base leads to less substituted alkene, in presence of strong base (not bulky) leads to more substituted alkene.

(d)

Interpretation Introduction

Interpretation:

The possible product should be drawn and identified for the given substrates during E2 elimination reaction.

Concept Introduction:

• Elimination reaction: In elimination reaction, two substituents are removed from the substrate to give the product in presence of base. Elimination reactions are two types, $E1$ and $E2$.
• $E1$ reaction: elimination follows stepwise mechanism.
• $E2$ reaction: elimination follows concerted pathway of mechanism.
• Elimination of compound in presence of bulky base leads to less substituted alkene, in presence of strong base (not bulky) leads to more substituted alkene.

(e)

Interpretation Introduction

Interpretation:

The major and minor products should be drawn for the given each elimination reactions.

Concept Introduction:

• Highly polarizable reagents are considered as strong nucleophiles if the conjugate acid of the nucleophile has little nature then those nucleophiles considered as weak bases too. If the reagent is not polarizable and has basic nature, then the reagent is considered as strong base.
• Reaction mechanism path is depending on both natures of substrate and reagent.
• If the reagent is strong base as well as strong nucleophile and the substrate is primary alkyl halide then the reaction follows $S_{N}2$ mechanism if the substrate is secondary alkyl halide then the reaction follows E2 mechanism. For $S_{N}2$ mechanism reagent should be strong nucleophile.
• If the substrate is tertiary alkyl halide, then the reaction follows ${\text{S}}_{\text{N}}\text{1}$ mechanism rather than ${\text{S}}_{\text{N}}2$ mechanism. (when the reagent is strong nucleophile).
• If the reagent is strong bulky base, then the reaction follows E2 mechanism. For E2 reaction, reagent should be strong base.

(f)

Interpretation Introduction

Interpretation:

Major and minor product should be drawn for the given substrates during elimination reaction.

Concept Introduction:

• Highly polarizable reagents are considered as strong nucleophiles if the conjugate acid of the nucleophile has little nature then those nucleophiles considered as weak bases too. If the reagent is not polarizable and has basic nature, then the reagent is considered as strong base.
• Reaction mechanism path is depending on both natures of substrate and reagent.
• If the reagent is strong base as well as strong nucleophile and the substrate is primary alkyl halide then the reaction follows $S_{N}2$ mechanism if the substrate is secondary alkyl halide then the reaction follows E2 mechanism. For $S_{N}2$ mechanism reagent should be strong nucleophile.
• If the substrate is tertiary alkyl halide, then the reaction follows ${\text{S}}_{\text{N}}\text{1}$ mechanism rather than ${\text{S}}_{\text{N}}2$ mechanism. (when the reagent is strong nucleophile).
• If the reagent is strong bulky base, then the reaction follows E2 mechanism. For E2 reaction, reagent should be strong base.

(g)

Interpretation Introduction

Interpretation:

Major and minor product should be drawn for the given substrates during elimination reaction.

Concept Introduction:

• Highly polarizable reagents are considered as strong nucleophiles if the conjugate acid of the nucleophile has little nature then those nucleophiles considered as weak bases too. If the reagent is not polarizable and has basic nature, then the reagent is considered as strong base.
• Reaction mechanism path is depending on both natures of substrate and reagent.
• If the reagent is strong base as well as strong nucleophile and the substrate is primary alkyl halide then the reaction follows $S_{N}2$ mechanism if the substrate is secondary alkyl halide then the reaction follows E2 mechanism. For $S_{N}2$ mechanism reagent should be strong nucleophile.
• If the substrate is tertiary alkyl halide, then the reaction follows ${\text{S}}_{\text{N}}\text{1}$ mechanism rather than ${\text{S}}_{\text{N}}2$ mechanism. (when the reagent is strong nucleophile).
• If the reagent is strong bulky base, then the reaction follows E2 mechanism. For E2 reaction, reagent should be strong base.

(h)

Interpretation Introduction

Interpretation:

Major and minor product should be drawn for the given substrates during elimination reaction.

Concept Introduction:

• Highly polarizable reagents are considered as strong nucleophiles if the conjugate acid of the nucleophile has little nature then those nucleophiles considered as weak bases too. If the reagent is not polarizable and has basic nature, then the reagent is considered as strong base.
• Reaction mechanism path is depending on both natures of substrate and reagent.
• If the reagent is strong base as well as strong nucleophile and the substrate is primary alkyl halide then the reaction follows $S_{N}2$ mechanism if the substrate is secondary alkyl halide then the reaction follows E2 mechanism. For $S_{N}2$ mechanism reagent should be strong nucleophile.
• If the substrate is tertiary alkyl halide, then the reaction follows ${\text{S}}_{\text{N}}\text{1}$ mechanism rather than ${\text{S}}_{\text{N}}2$ mechanism. (when the reagent is strong nucleophile).
• If the reagent is strong bulky base, then the reaction follows E2 mechanism. For E2 reaction, reagent should be strong base.

(i)

Interpretation Introduction

Interpretation:

Major and minor product should be drawn for the given substrates during elimination reaction.

Concept Introduction:

• Highly polarizable reagents are considered as strong nucleophiles if the conjugate acid of the nucleophile has little nature then those nucleophiles considered as weak bases too. If the reagent is not polarizable and has basic nature, then the reagent is considered as strong base.
• Reaction mechanism path is depending on both natures of substrate and reagent.
• If the reagent is strong base as well as strong nucleophile and the substrate is primary alkyl halide then the reaction follows $S_{N}2$ mechanism if the substrate is secondary alkyl halide then the reaction follows E2 mechanism. For $S_{N}2$ mechanism reagent should be strong nucleophile.
• If the substrate is tertiary alkyl halide, then the reaction follows ${\text{S}}_{\text{N}}\text{1}$ mechanism rather than ${\text{S}}_{\text{N}}2$ mechanism. (when the reagent is strong nucleophile).
• If the reagent is strong bulky base, then the reaction follows E2 mechanism. For E2 reaction, reagent should be strong base.

(j)

Interpretation Introduction

Interpretation:

Major and minor product should be drawn for the given substrates during elimination reaction.

Concept Introduction:

• Highly polarizable reagents are considered as strong nucleophiles if the conjugate acid of the nucleophile has little nature then those nucleophiles considered as weak bases too. If the reagent is not polarizable and has basic nature, then the reagent is considered as strong base.
• Reaction mechanism path is depending on both natures of substrate and reagent.
• If the reagent is strong base as well as strong nucleophile and the substrate is primary alkyl halide then the reaction follows $S_{N}2$ mechanism if the substrate is secondary alkyl halide then the reaction follows E2 mechanism. For $S_{N}2$ mechanism reagent should be strong nucleophile.
• If the substrate is tertiary alkyl halide, then the reaction follows ${\text{S}}_{\text{N}}\text{1}$ mechanism rather than ${\text{S}}_{\text{N}}2$ mechanism. (when the reagent is strong nucleophile).
• If the reagent is strong bulky base, then the reaction follows E2 mechanism. For E2 reaction, reagent should be strong base.

(k)

Interpretation Introduction

Interpretation:

Major and minor product should be drawn for the given substrates during elimination reaction.

Concept Introduction:

• Highly polarizable reagents are considered as strong nucleophiles if the conjugate acid of the nucleophile has little nature then those nucleophiles considered as weak bases too. If the reagent is not polarizable and has basic nature, then the reagent is considered as strong base.
• Reaction mechanism path is depending on both natures of substrate and reagent.
• If the reagent is strong base as well as strong nucleophile and the substrate is primary alkyl halide then the reaction follows $S_{N}2$ mechanism if the substrate is secondary alkyl halide then the reaction follows E2 mechanism. For $S_{N}2$ mechanism reagent should be strong nucleophile.
• If the substrate is tertiary alkyl halide, then the reaction follows ${\text{S}}_{\text{N}}\text{1}$ mechanism rather than ${\text{S}}_{\text{N}}2$ mechanism. (when the reagent is strong nucleophile).
• If the reagent is strong bulky base, then the reaction follows E2 mechanism. For E2 reaction, reagent should be strong base.

(l)

Interpretation Introduction

Interpretation:

Major and minor product should be drawn for the given substrates during elimination reaction.

Concept Introduction:

• Highly polarizable reagents are considered as strong nucleophiles if the conjugate acid of the nucleophile has little nature then those nucleophiles considered as weak bases too. If the reagent is not polarizable and has basic nature, then the reagent is considered as strong base.
• Reaction mechanism path is depending on both natures of substrate and reagent.
• If the reagent is strong base as well as strong nucleophile and the substrate is primary alkyl halide then the reaction follows $S_{N}2$ mechanism if the substrate is secondary alkyl halide then the reaction follows E2 mechanism. For $S_{N}2$ mechanism reagent should be strong nucleophile.
• If the substrate is tertiary alkyl halide, then the reaction follows ${\text{S}}_{\text{N}}\text{1}$ mechanism rather than ${\text{S}}_{\text{N}}2$ mechanism. (when the reagent is strong nucleophile).
• If the reagent is strong bulky base, then the reaction follows E2 mechanism. For E2 reaction, reagent should be strong base.

(m)

Interpretation Introduction

Interpretation:

Major and minor product should be drawn for the given substrates during elimination reaction.

Concept Introduction:

• Highly polarizable reagents are considered as strong nucleophiles if the conjugate acid of the nucleophile has little nature then those nucleophiles considered as weak bases too. If the reagent is not polarizable and has basic nature, then the reagent is considered as strong base.
• Reaction mechanism path is depending on both natures of substrate and reagent.
• If the reagent is strong base as well as strong nucleophile and the substrate is primary alkyl halide then the reaction follows $S_{N}2$ mechanism if the substrate is secondary alkyl halide then the reaction follows E2 mechanism. For $S_{N}2$ mechanism reagent should be strong nucleophile.
• If the substrate is tertiary alkyl halide, then the reaction follows ${\text{S}}_{\text{N}}\text{1}$ mechanism rather than ${\text{S}}_{\text{N}}2$ mechanism. (when the reagent is strong nucleophile).
• If the reagent is strong bulky base, then the reaction follows E2 mechanism. For E2 reaction, reagent should be strong base.

(n)

Interpretation Introduction

Interpretation:

Major and minor product should be drawn for the given substrates during elimination reaction.

Concept Introduction:

• Highly polarizable reagents are considered as strong nucleophiles if the conjugate acid of the nucleophile has little nature then those nucleophiles considered as weak bases too. If the reagent is not polarizable and has basic nature, then the reagent is considered as strong base.
• Reaction mechanism path is depending on both natures of substrate and reagent.
• If the reagent is strong base as well as strong nucleophile and the substrate is primary alkyl halide then the reaction follows $S_{N}2$ mechanism if the substrate is secondary alkyl halide then the reaction follows E2 mechanism. For $S_{N}2$ mechanism reagent should be strong nucleophile.
• If the substrate is tertiary alkyl halide, then the reaction follows ${\text{S}}_{\text{N}}\text{1}$ mechanism rather than ${\text{S}}_{\text{N}}2$ mechanism. (when the reagent is strong nucleophile).
• If the reagent is strong bulky base, then the reaction follows E2 mechanism. For E2 reaction, reagent should be strong base.