Chapter 14, Problem 14.33SP

(a)

Interpretation Introduction

To determine: The products of the given reaction.

Interpretation: The products of the given reaction are to be predicted.

Concept introduction: When ethers react with $\text{HBr}$ or $\text{HI}$, protonation takes places. The protonated ether undergoes ${\text{S}}_{\text{N}}\text{2}$ cleavage. The ether oxygen is protonated by strong acid $\text{HBr}$ or $\text{HI}$. The unimolecualr ${\text{S}}_{\text{N}}1$ meachnism will occur if carbocation is stablised.

(b)

Interpretation Introduction

To determine: The products of the given reaction.

Interpretation: The products of the given reaction are to be predicted.

Concept introduction: When ethers react with $\text{HBr}$ or $\text{HI}$, protonation takes places. The protonated ether undergoes ${\text{S}}_{\text{N}}\text{2}$ cleavage. The ether oxygen is protonated by strong acid $\text{HBr}$ or $\text{HI}$. The unimolecualr ${\text{S}}_{\text{N}}1$ meachnism will occur if carbocation is stablised.

(c)

Interpretation Introduction

To determine: The products of the given reaction.

Interpretation: The products of the given reaction are to be predicted.

Concept introduction: When ethers react with $\text{HBr}$ or $\text{HI}$, protonation takes places. The protonated ether undergoes ${\text{S}}_{\text{N}}\text{2}$ cleavage. The ether oxygen is protonated by strong acid $\text{HBr}$ or $\text{HI}$. The unimolecualr ${\text{S}}_{\text{N}}1$ meachnism will occur if carbocation is stablised.

(d)

Interpretation Introduction

To determine: The products of the given reaction.

Interpretation: The products of the given reaction are to be predicted.

Concept introduction: When ethers react with $\text{HBr}$ or $\text{HI}$, protonation takes places. The protonated ether undergoes ${\text{S}}_{\text{N}}\text{2}$ cleavage. The ether oxygen is protonated by strong acid $\text{HBr}$ or $\text{HI}$. The unimolecualr ${\text{S}}_{\text{N}}1$ meachnism will occur if carbocation is stablised.

(e)

Interpretation Introduction

To determine: The products of the given reaction.

Interpretation: The products of the given reaction are to be predicted.

Concept introduction: When ethers react with $\text{HBr}$ or $\text{HI}$, protonation takes places. The protonated ether undergoes ${\text{S}}_{\text{N}}\text{2}$ cleavage. The ether oxygen is protonated by strong acid $\text{HBr}$ or $\text{HI}$. The unimolecualr ${\text{S}}_{\text{N}}1$ meachnism will occur if carbocation is stablised.

(f)

Interpretation Introduction

To determine: The products of the given reaction.

Interpretation: The products of the given reaction are to be predicted.

Concept introduction: Strong electrophile is formed when epoxides are protonated. The electrophile is attacked by neucleophile and ring opening takes place. It is followed by deprotonation.

(g)

Interpretation Introduction

To determine: The products of the given reaction.

Interpretation: The products of the given reaction are to be predicted.

Concept introduction: Strong electrophile is formed when epoxides are protonated. The electrophile is attacked by neucleophile and ring opening takes place. It is followed by deprotonation.

(h)

Interpretation Introduction

To determine: The products of the given reaction.

Interpretation: The products of the given reaction are to be predicted.

Concept introduction: Strong electrophile is formed when epoxides are protonated. The electrophile is attacked by neucleophile and ring opening takes place. It is followed by deprotonation.

(i)

Interpretation Introduction

To determine: The products of the given reaction.

Interpretation: The products of the given reaction are to be predicted.

Concept introduction: When ethers react with $\text{HBr}$ or $\text{HI}$, protonation takes places. The protonated ether undergoes ${\text{S}}_{\text{N}}\text{2}$ cleavage. The ether oxygen is protonated by strong acid $\text{HBr}$ or $\text{HI}$. The unimolecualr ${\text{S}}_{\text{N}}1$ meachnism will occur if carbocation is stablised.

(j)

Interpretation Introduction

To determine: The products of the given reaction.

Interpretation: The products of the given reaction are to be predicted.

Concept introduction: Grignard reagent acts as neucleophile in the ring opening of epoxides. Addition of neucleophile to epoxide takes place. It is followed by protonation workup.

(k)

Interpretation Introduction

To determine: The products of the given reaction.

Interpretation: The products of the given reaction are to be predicted.

Concept introduction: Alkenes are converted into epoxides with the help of peroxy acids. The most commonly used acid for epoxidation is meta-chloroperoxybenzoic acid. It is soluble in aprotic solvents such as ${\text{CH}}_{\text{2}}{\text{Cl}}_{\text{2}}$.

(l)

Interpretation Introduction

To determine: The products of the given reaction.

Interpretation: The products of the given reaction are to be predicted.

Concept introduction: When ethers react with $\text{HBr}$ or $\text{HI}$, protonation takes places. The protonated ether undergoes ${\text{S}}_{\text{N}}\text{2}$ cleavage. The ether oxygen is protonated by strong acid $\text{HBr}$ or $\text{HI}$. The unimolecualr ${\text{S}}_{\text{N}}1$ meachnism will occur if carbocation is stablised.

(m)

Interpretation Introduction

To determine: The products of the given reaction.

Interpretation: The products of the given reaction are to be predicted.

Concept introduction: Epoxide oxygen is protonated under acidic conditions. The nucleophile attack more substituted position under acidic conditions. But under basic conditions, nucleophile attack less substituted position.

(n)

Interpretation Introduction

To determine: The products of the given reaction.

Interpretation: The products of the given reaction are to be predicted.

Concept introduction: Epoxide oxygen is protonated under acidic conditions. The nucleophile attack more substituted position under acidic conditions. But under basic conditions, nucleophile attack less substituted position.