Chapter 15, Problem 15.61P

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

a. b. e. g.

b. d. f. h.

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 15.61P

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

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. In the next step, bromine atom is eliminated from bromocyclopentane to form cyclopentane in the presence of tert-butoxide. 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 15.61P

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

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. In the next step, bromine atom is eliminated from bromocyclopentane to form cyclopentane in the presence of tert-butoxide. In the last step, bromination takes place allylic position in the presence of NBS and light as shown 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 15.61P

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

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 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 15.61P

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

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. In the next step, bromine atom is eliminated from bromocyclopentane to form cyclopentane in the presence of tert-butoxide. In the last step, chlorination in the presence of ${\text{Cl}}_{\text{2}}$ converts cyclopentene to dichloropentane 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 15.61P

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

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 5.

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.

Interpretation Introduction

(f)

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 15.61P

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

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 6.

Figure 6

Conclusion

The synthesis of given compound from cyclopentane by the use of any other organic or inorganic reagent is shown in Figure 6.

Interpretation Introduction

(g)

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 15.61P

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

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 7.

Figure 7

Conclusion

The synthesis of given compound from cyclopentane by the use of any other organic or inorganic reagent is shown in Figure 7.

Interpretation Introduction

(h)

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 15.61P

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

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 8

Conclusion

The synthesis of given compound from cyclopentane by the use of any other organic or inorganic reagent is shown in Figure 8.