Chapter 7, Problem 44P

(a)

Interpretation Introduction

Interpretation:Whether ${\text{NaSCH}}_{\text{3}}$ in ${\text{CH}}_{\text{3}}\text{OH}$ will give ${\text{S}}_{\text{N}}2$ with primary alkyl halide, $\text{E2}$ with primary alkyl halide, ${\text{S}}_{\text{N}}\text{2}$ with secondary alkylhalide or $\text{E2}$ with secondary alkylhalide should be chosen.

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 $\text{E1}$ .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:Whether ${\left({\text{CH}}_{\text{3}}\right)}_2\text{CHOLi}$ in ${\left({\text{CH}}_{\text{3}}\right)}_2\text{CHOH}$ reagent will give ${\text{S}}_{\text{N}}2$ with primary alkyl halide, $\text{E2}$ with primary alkyl halide, ${\text{S}}_{\text{N}}\text{2}$ with secondary alkylhalide or $\text{E2}$ with secondary alkylhalide should be chosen.

Concept introduction: The most likely mechanisms for different kinds of alkyl halides with various nucleophiles is given as follows:

  

(c)

Interpretation Introduction

Interpretation:Whether ${\text{NaNH}}_2$ in ${\text{NH}}_3$ reagent will give ${\text{S}}_{\text{N}}2$ with primary alkyl halide, $\text{E2}$ with primary alkyl halide, ${\text{S}}_{\text{N}}\text{2}$ with secondary alkylhalide or $\text{E2}$ with secondary alkylhalide should be chosen.

Concept introduction: The most likely mechanisms for different kinds of alkyl halides with various nucleophiles is given as follows:

  

(d)

Interpretation Introduction

Interpretation:Whether $\text{KCN}$ in DMSO reagent will give ${\text{S}}_{\text{N}}2$ with primary alkyl halide, $\text{E2}$ with primary alkyl halide, ${\text{S}}_{\text{N}}\text{2}$ with secondary alkylhalide or $\text{E2}$ with secondary alkylhalide should be chosen.

Concept introduction: The most likely mechanisms for different kinds of alkyl halides with various nucleophiles is given as follows:

  

(e)

Interpretation Introduction

Interpretation:Whetherbelow reagent will give ${\text{S}}_{\text{N}}2$ with primary alkyl halide, $\text{E2}$ with primary alkyl halide, ${\text{S}}_{\text{N}}\text{2}$ with secondary alkylhalide or $\text{E2}$ with secondary alkylhalide should be identified.

  

Concept introduction: The most likely mechanisms for different kinds of alkyl halides with various nucleophiles is given as follows:

  

(f)

Interpretation Introduction

Interpretation:Whether ${\text{CH}}_3{\text{CH}}_{\text{2}}{\text{CH}}_{\text{2}}\text{COONa}$ in DMF reagent will give ${\text{S}}_{\text{N}}2$ with primary alkyl halide, $\text{E2}$ with primary alkyl halide, ${\text{S}}_{\text{N}}\text{2}$ with secondary alkylhalide or $\text{E2}$ with secondary alkylhalide should be chosen.

Concept introduction: The most likely mechanisms for different kinds of alkyl halides with various nucleophiles is given as follows: