Chapter 16, Problem 16.16P

Draw the products formed when each diene is treated with one equivalent of $\text{HCl}$.

a. b. c. d.

Interpretation Introduction

(a)

Interpretation: The product formed by the reaction of given diene with one equivalent of $\text{HCl}$ is to be drawn.

Concept introduction: Diene is a hydrocarbon that contains two $\text{C}=\text{C}$ double bonds in a compound. Conjugated diene consists of two double bonds that are separated by a single bond, whereas isolated diene also consists of two double bond but they are separated by two more carbon atoms.

Answer to Problem 16.16P

The product formed by the reaction of given diene with one equivalent of $\text{HCl}$ is shown as:

Explanation of Solution

Conjugated dienes undergoes electrophilic addition to gives a mixture of products that is $1,2-\text{addition}\text{product}$ and $1,4-\text{addition}\text{product}$, whereas isolated diene give one product followed by markovnikov’s rule.

Markovnikov addition of $\text{HCl}$ results in the formation of $1,2-\text{addition}\text{product}$, whereas addition of $\text{HCl}$ to the two end carbons of the diene result in the formation of $1,4-\text{addition}\text{product}$.

The given diene is shown below.

Figure 1

The given diene is a conjugated diene. The attack of ${\text{H}}^{+}$ on the given diene results in the formation of secondary allylic carbocation. Therefore, two resonance structures are possible for allylic carbocation as shown below.

Figure 2

In the next step, chlorine as a nucleophile will attack on the carbocation to give constitutional isomers. Thus, the product formed by the reaction of given diene with one equivalent of $\text{HCl}$ is shown is shown below.

Figure 3

Conclusion

The product formed by the reaction of given diene with one equivalent of $\text{HCl}$ is shown in Figure 3.

Interpretation Introduction

(b)

Interpretation: The product formed by the reaction of given diene with one equivalent of $\text{HCl}$ is to be drawn.

Concept introduction: Diene is a hydrocarbon that contains two $\text{C}=\text{C}$ double bonds in a compound. Conjugated diene consists of two double bonds that are separated by a single bond, whereas isolated diene also consists of two double bond but they are separated by two more carbon atoms.

Answer to Problem 16.16P

The product formed by the reaction of given diene with one equivalent of $\text{HCl}$ is shown as:

Explanation of Solution

Conjugated dienes undergoes electrophilic addition to gives a mixture of products that is $1,2-\text{addition}\text{product}$ and $1,4-\text{addition}\text{product}$, whereas isolated diene give one product followed by markovnikov’s rule.

Markovnikov’s rule states that the positive part of acid attached to that carbon atom in $\text{C}=\text{C}$ bond which carries maximum number of hydrogen atoms and the negative part of acid will attach to that carbon atom in $\text{C}=\text{C}$ bond which has minimum number of hydrogen atoms.

The given diene is shown below.

Figure 4

The given diene is an isolated diene. The attack of ${\text{H}}^{+}$ on the given diene results in the formation of stable carbocation. Therefore, only one carbocation is formed by the attack of ${\text{H}}^{+}$ ion as shown below.

Figure 5

In the next step, chlorine as a nucleophile will attack on the carbocation to form desired product. Thus, the product formed by the reaction of given diene with one equivalent of $\text{HCl}$ is shown is shown below.

Figure 6

Conclusion

The product formed by the reaction of given diene with one equivalent of $\text{HCl}$ is shown in Figure 6.

Interpretation Introduction

(c)

Interpretation: The product formed by the reaction of given diene with one equivalent of $\text{HCl}$ is to be drawn.

Concept introduction: Diene is a hydrocarbon that contains two $\text{C}=\text{C}$ double bonds in a compound. Conjugated diene consists of two double bonds that are separated by a single bond, whereas isolated diene also consists of two double bond but they are separated by two more carbon atoms.

Answer to Problem 16.16P

The product formed by the reaction of given diene with one equivalent of $\text{HCl}$ is shown as:

Explanation of Solution

Conjugated dienes undergoes electrophilic addition to gives a mixture of products that is $1,2-\text{addition}\text{product}$ and $1,4-\text{addition}\text{product}$, whereas isolated diene give one product followed by markovnikov’s rule.

Markovnikov addition of $\text{HCl}$ results in the formation of $1,2-\text{addition}\text{product}$, whereas addition of $\text{HCl}$ to the two end carbons of the diene result in the formation of $1,4-\text{addition}\text{product}$.

The given diene is shown below.

Figure 7

The given diene is a conjugated diene. The attack of ${\text{H}}^{+}$ on the given diene results in the formation of secondary allylic carbocation. Therefore, two resonance structures are possible for allylic carbocation as shown below.

Figure 8

In the next step, chlorine as a nucleophile will attack on the carbocation to give constitutional isomers. Thus, the product formed by the reaction of given diene with one equivalent of $\text{HCl}$ is shown is shown below.

Figure 9

Conclusion

The product formed by the reaction of given diene with one equivalent of $\text{HCl}$ is shown in Figure 9.

Interpretation Introduction

(d)

Interpretation: The product formed by the reaction of given diene with one equivalent of $\text{HCl}$ is to be drawn.

Concept introduction: Diene is a hydrocarbon that contains two $\text{C}=\text{C}$ double bonds in a compound. Conjugated diene consists of two double bonds that are separated by a single bond, whereas isolated diene also consists of two double bond but they are separated by two more carbon atoms.

Answer to Problem 16.16P

The product formed by the reaction of given diene with one equivalent of $\text{HCl}$ is shown as:

Explanation of Solution

Conjugated dienes undergoes electrophilic addition to gives a mixture of products that is $1,2-\text{addition}\text{product}$ and $1,4-\text{addition}\text{product}$, whereas isolated diene give one product followed by markovnikov’s rule.

Markovnikov addition of $\text{HCl}$ results in the formation of $1,2-\text{addition}\text{product}$, whereas addition of $\text{HCl}$ to the two end carbons of the diene result in the formation of $1,4-\text{addition}\text{product}$.

The given diene is shown below.

Figure 10

The given diene is a conjugated diene. The attack of ${\text{H}}^{+}$ on the given diene results in the formation of tertiary carbocation. Therefore, two resonance structures are possible for allylic carbocation as shown below.

Figure 11

In the next step, chlorine as a nucleophile will attack on the carbocation to give constitutional isomers. Thus, the product formed by the reaction of given diene with one equivalent of $\text{HCl}$ is shown is shown below.

Figure 12

Conclusion

The product formed by the reaction of given diene with one equivalent of $\text{HCl}$ is shown in Figure 12.