Chapter 7, Problem 42P

(a)

Interpretation Introduction

Interpretation: The two main products of the indicated reaction should be drawn.

  

Concept introduction:Carbocations generated from alkyl halides have two fates; they can be either trapped by nucleophiles to give substitution product or may deprotonate to yield a small amount of alkene.

If the leaving group present eliminates along with a proton in absence of any strong nucleophile the double bond formation might occur. Such reactions are known as two-step unimolecuar elimination, abbreviated as $\text{E2}$ .If the still higher concentration is employed, reaction proceeds via bimolecular elimination. On the other hand, the weak base waits until the carbocation is formed and the type of elimination with a relatively weak base is two-step elimination or $\text{E1}$ .

(b)

Interpretation Introduction

Interpretation: The mechanism I should be identified.

Concept introduction: Carbocations generated from alkyl halides have two fates; they can be either trapped by nucleophiles to give substitution product or may deprotonate to yield a small amount of alkene.

If the leaving group present eliminates along with a proton in absence of any strong nucleophile the double bond formation might occur. Such reactions are known as two-step unimolecuar elimination, abbreviated as $\text{E2}$ .If the still higher concentration is employed, reaction proceeds via bimolecular elimination. On the other hand, the weak base waits until the carbocation is formed and the type of elimination with a relatively weak base is two-step elimination or $\text{E1}$ .

(c)

Interpretation Introduction

Interpretation: The mechanism II should be identified.

Concept introduction: Carbocations generated from alkyl halides have two fates; they can be either trapped by nucleophiles to give substitution product or may deprotonate to yield a small amount of alkene.

If the leaving group present eliminates along with a proton in absence of any strong nucleophile the double bond formation might occur. Such reactions are known as two-step unimolecuar elimination, abbreviated as $\text{E2}$ .If the still higher concentration is employed, reaction proceeds via bimolecular elimination. On the other hand, the weak base waits until the carbocation is formed and the type of elimination with a relatively weak base is two-step elimination or $\text{E1}$ .

(d)

Interpretation Introduction

Interpretation: The approximate molar concentration of sodium methoxide that would cause the two mechanisms to proceed at same rate mechanism should be identified.

Concept introduction: Carbocations generated from alkyl halides have two fates; they can be either trapped by nucleophiles to give substitution product or may deprotonate to yield a small amount of alkene.

If the leaving group present eliminates along with a proton in absence of any strong nucleophile the double bond formation might occur. Such reactions are known as two-step unimolecuar elimination, abbreviated as $\text{E2}$ .If the still higher concentration is employed, reaction proceeds via bimolecular elimination. On the other hand, the weak base waits until the carbocation is formed and the type of elimination with a relatively weak base is two-step elimination or $\text{E1}$ .