Chapter 15, Problem 15.57P

Devise a synthesis of each compound from cyclopentane and any other required organic or inorganic reagents.

a. b. c. d. e.

Interpretation Introduction

(a)

Interpretation: The synthesis of given compound from cyclopentane by the use of any other organic or inorganic reagent is to be stated.

Concept introduction: Alkenes undergo bromination reaction at primary, secondary and tertiary carbon atom through free radical mechanism on reaction with ${\text{Br}}_{\text{2}}$ in the presence of light or heat. However, alkenes undergo bromination at allylic carbon atom on reaction with ${\text{Br}}_{\text{2}}$ in the presence of light or heat.

Answer to Problem 15.57P

The synthesis of given compound from cyclopentane by the use of any other organic or inorganic reagent is,

Figure 1

Explanation of Solution

Cyclopentane is used as a starting material and it converts into bromocyclopentane on treatment with ${\text{Br}}_{\text{2}}$ in the presence of light or heat. The bromine group is converted into hydroxyl group when bromocyclopentane is treated with $\text{KOH}$. The synthesis of given compound from cyclopentane by the use of any other organic or inorganic reagent is shown in Figure 1.

Figure 1

Conclusion

The synthesis of given compound from cyclopentane by the use of any other organic or inorganic reagent is shown in Figure 1.

Interpretation Introduction

(b)

Interpretation: The synthesis of given compound from cyclopentane by the use of any other organic or inorganic reagent is to be stated.

Concept introduction: Alkenes undergo bromination reaction at primary, secondary and tertiary carbon atom through free radical mechanism on reaction with ${\text{Br}}_{\text{2}}$ in the presence of light or heat. However, alkenes undergo bromination at allylic carbon atom on reaction with ${\text{Br}}_{\text{2}}$ in the presence of light or heat.

Answer to Problem 15.57P

The synthesis of given compound from cyclopentane by the use of any other organic or inorganic reagent is,

Figure 2

Explanation of Solution

In the first step, cyclopentane undergoes bromination when it is treated with ${\text{Br}}_{\text{2}}$ in the presence of light or heat. In the next step, bromine atom is eliminated from bromocyclopentane to form cyclopentane in the presence of tert-butoxide. The desired product is formed when cyclopentene reacts with m-chloroperbenzoic acid $\left(m\text{CPBA}\right)$ as shown in Figure 2.

Figure 2

Conclusion

The synthesis of given compound from cyclopentane by the use of any other organic or inorganic reagent is shown in Figure 2.

Interpretation Introduction

(c)

Interpretation: The synthesis of given compound from cyclopentane by the use of any other organic or inorganic reagent is to be stated.

Concept introduction: Alkenes undergo bromination reaction at primary, secondary and tertiary carbon atom through free radical mechanism on reaction with ${\text{Br}}_{\text{2}}$ in the presence of light or heat. However, alkenes undergo bromination at allylic carbon atom on reaction with ${\text{Br}}_{\text{2}}$ in the presence of light or heat.

Answer to Problem 15.57P

The synthesis of given compound from cyclopentane by the use of any other organic or inorganic reagent is,

Figure 3

Explanation of Solution

In the first step, cyclopentane undergoes bromination when it is treated with ${\text{Br}}_{\text{2}}$ in the presence of light or heat. In the next step, bromine atom is eliminated from bromocyclopentane to form cyclopentane in the presence of tert-butoxide. Cyclopentene then undergoes bromination at allylic position on reaction with NBS in presence of light followed by addition reaction with ${\text{Br}}_{\text{2}}$ to give desired product as shown in Figure 3.

Figure 3

Conclusion

The synthesis of given compound from cyclopentane by the use of any other organic or inorganic reagent is shown in Figure 3.

Interpretation Introduction

(d)

Interpretation: The synthesis of given compound from cyclopentane by the use of any other organic or inorganic reagent is to be stated.

Concept introduction: Alkenes undergo bromination reaction at primary, secondary and tertiary carbon atom through free radical mechanism on reaction with ${\text{Br}}_{\text{2}}$ in the presence of light or heat. However, alkenes undergo bromination at allylic carbon atom on reaction with ${\text{Br}}_{\text{2}}$ in the presence of light or heat.

Answer to Problem 15.57P

The synthesis of given compound from cyclopentane by the use of any other organic or inorganic reagent is,

Figure 4

Explanation of Solution

In the first step, cyclopentane undergoes bromination when it is treated with ${\text{Br}}_{\text{2}}$ in the presence of light or heat. In the next step, bromine atom is eliminated from bromocyclopentane to form cyclopentane in the presence of tert-butoxide. Cyclopentene then undergoes bromination at allylic position on reaction with NBS in presence of light. The bromine group is converted into hydroxyl group when this product is treated with $\text{KOH}$. This leads to the formation of desired product as shown in Figure 4.

Figure 4

Conclusion

The synthesis of given compound from cyclopentane by the use of any other organic or inorganic reagent is shown in Figure 4.

Interpretation Introduction

(e)

Interpretation: The synthesis of given compound from cyclopentane by the use of any other organic or inorganic reagent is to be stated.

Concept introduction: Alkenes undergo bromination reaction at primary, secondary and tertiary carbon atom through free radical mechanism on reaction with ${\text{Br}}_{\text{2}}$ in the presence of light or heat. However, alkenes undergo bromination at allylic carbon atom on reaction with ${\text{Br}}_{\text{2}}$ in the presence of light or heat.

Answer to Problem 15.57P

The synthesis of given compound from cyclopentane by the use of any other organic or inorganic reagent is,

Figure 5

Explanation of Solution

In the first step, cyclopentane undergoes bromination when it is treated with ${\text{Br}}_{\text{2}}$ in the presence of light or heat. In the next step, bromine atom is eliminated from bromocyclopentane to form cyclopentane in the presence of tert-butoxide. Cyclopentene then undergoes addition reaction with ${\text{Br}}_{\text{2}}$ to give $1,2$-dibromocyclopentane. In the next two steps, bromine atom is converted into nitrile and hydroxyl group on reaction with $\text{KCN}$ and $\text{KOH}$, respectively, which leads to the formation of desired product.

Figure 5

Conclusion

The synthesis of given compound from cyclopentane by the use of any other organic or inorganic reagent is shown in Figure 5.