Chapter 13, Problem 59P

What alkene is needed as a starting material to prepare each of the following alkyl halides or dihalides? In each case, also indicate what reagent is needed to react with the alkene.

a. $C{H}_{3}C{H}_{2}Br$

Interpretation Introduction

(a)

Interpretation:

The starting material and the reagents needed to prepare following alkyl halide should be determined:

  $C{H}_{3}C{H}_{2}Br$

Concept Introduction:

Alkenes are hydrocarbon molecules that consist a carbon-carbon double bond which has the general formula of $C_n{H}_{2n}$ .Alkyl halides are the hydrocarbon molecules which contains halogen atoms within the molecules.

Reaction of alkene with $HX(X=Cl\text{ or }Br)$ will form saturated alkyl halides and the reaction is called as a hydro halogenation reaction.

Answer to Problem 59P

Starting alkene- $C{H}_2=C{H}_2$

Reagent - $HBr$

Explanation of Solution

Unsaturated alkene molecules react with $HX(X=Cl\text{ or }Br)$ and form saturated alkyl halides. Bond between hydrogen and halogen in the $HX$ , is broken and also a one bond between two carbon-carbon bond is broken, meanwhile new two bonds of $C-X$ and $C-H$ are formed. In this reaction, resulting molecule contains bromide, hence $X$ should be $Br$.

Refer to the below reaction:

  

Interpretation Introduction

(b)

Interpretation:

The starting material and the reagents needed to prepare following alkyl halide should be determined:

  

Concept Introduction:

Alkenes are hydrocarbon molecules that consist a carbon-carbon double bond which has the general formula of $C_n{H}_{2n}$ .Alkyl halides are the hydrocarbon molecules which contains halogen atoms within the molecules.

Reaction of alkene with $HX(X=Cl\text{ or }Br)$ will form saturated alkyl halides and the reaction is called as a hydro halogenation reaction.

Answer to Problem 59P

  

Starting alkene −

Reagent - $HCl$

Explanation of Solution

Unsaturated alkene molecules react with $HX(X=Cl\text{ or }Br)$ and form saturated alkyl halides. Bond between hydrogen and halogen in the $HX$ , is broken and also a one bond between two carbon-carbon bond is broken, meanwhile new two bonds of $C-X$ and $C-H$ are formed. In this reaction, resulting molecule contains chlorine, hence $X$ should be $Cl$.

Refer to the below reaction;

  

Interpretation Introduction

(c)

Interpretation:

The starting material and the reagents needed to prepare following alkyl halide should be determined:

  

Concept Introduction:

Alkenes are hydrocarbon molecules that consist a carbon-carbon double bond which has the general formula of $C_n{H}_{2n}$ .Dihalides are the molecules which have two halogen atoms in a molecule.

Reaction of alkene with $X_2(X_2=B{r}_{2}orC{l}_2)$ will form saturated dihalides and the reaction is called as a halogenation reaction.

Answer to Problem 59P

   Starting alkene −

Reagent - $C{l}_2$

Explanation of Solution

Unsaturated alkene molecules react with $X_2(X_2=B{r}_{2}orC{l}_2)$ and form saturated dihalides. Bond between two X in the $X_2(X_2=B{r}_{2}orC{l}_2)$ , is broken and also a one bond between two carbon-carbon bond is broken, meanwhile new two bonds of $C-X$ are formed.In this reaction resulting molecule contains chlorine atoms, hence $X$ should be $Cl$.

Refer to the below reaction;

  

Interpretation Introduction

(d)

Interpretation:

The starting material and the reagents needed to prepare following alkyl halide should be determined:

  

Concept Introduction:

Alkenes are hydrocarbon molecules that consist a carbon-carbon double bond which has the general formula of $C_n{H}_{2n}$ .Dihalides are the molecules which have two halogen atoms in a molecule.

Reaction of alkene with $X_2(X_2=B{r}_{2}orC{l}_2)$ will form saturated dihalides and the reaction is called as a halogenation reaction.

Answer to Problem 59P

Starting alkene − $C{H}_2=CH-C{H}_{2}CH{(C{H}_3)}_2$

Reagent - $B{r}_2$

Explanation of Solution

Unsaturated alkene molecules react with $X_2(X_2=B{r}_{2}orC{l}_2)$ and form saturated dihalides. Bond between two X in the $X_2(X_2=B{r}_{2}orC{l}_2)$ , is broken and also a one bond between two carbon-carbon bond is broken, meanwhile new two bonds of $C-X$ are formed. In this reaction resulting molecule contains bromine atoms, hence $X$ should be $Br$.

Refer to the below reaction:

  $C{H}_2=CH-C{H}_{2}CH{(C{H}_3)}_2\stackrel{B{r}_2}{\to }C{H}_{2}Br-CHBr-C{H}_{2}CH{(C{H}_3)}_2$