Chapter 24, Problem 24.40P

Draw the product formed from a Claisen reaction with the given starting materials using ${}^{-}\text{OEt}$, $\text{EtOH}$.

a. ${\text{CH}}_{\text{3}}{\text{CH}}_{\text{2}}{\text{CH}}_{\text{2}}{\text{CO}}_{\text{2}}\text{Et}+{\text{C}}_{\text{6}}{\text{H}}_{\text{5}}{\text{CO}}_{\text{2}}\text{Et}$

b. ${\text{CH}}_{\text{3}}{\text{CH}}_{\text{2}}{\text{CH}}_{\text{2}}{\text{CO}}_{\text{2}}\text{Et}+{\left({\text{CH}}_{\text{3}}\right)}_2\text{C}=\text{O}$

c. ${\text{EtO}}_{\text{2}}\text{CC}{\left({\text{CH}}_{\text{3}}\right)}_{\text{2}}{\text{CH}}_{\text{2}}{\text{CH}}_{\text{2}}{\text{CH}}_{\text{2}}{\text{CO}}_{\text{2}}\text{Et}$ e. f.

d. ${\text{CH}}_{\text{3}}{\text{CH}}_{\text{3}}{\text{CO}}_{\text{2}}\text{Et}+{\left(\text{EtO}\right)}_2\text{C}=\text{O}$

Interpretation Introduction

(a)

Interpretation: The product that is formed from the Claisen reaction of the given starting materials by using ${}^{-}\text{OEt}$, $\text{EtOH}$ is to be drawn.

Concept introduction: Claisen condensation is a reaction in organic chemistry which is used to generate carbon-carbon bond between two ester molecules. These two ester molecules use an alkoxide base in alcohol to form a $\text{β-keto}\text{ester}$.

Answer to Problem 24.40P

The product that is formed from the Claisen reaction of the given starting materials by using ${}^{-}\text{OEt}$, $\text{EtOH}$ is,

Explanation of Solution

The product that is formed from the Claisen reaction of the given starting materials by using ${}^{-}\text{OEt}$, $\text{EtOH}$ is shown as,

Figure 1

In this reaction, ethyl butyrate is treated with a strong base, $\text{NaOEt}$ which leads to the elimination of a proton from $\text{α}-$ carbon atom. This elimination leads to the formation of an enolate ion. Then, this enolate ion reacts with the given ester to form the desired product ethyl $2$-benzoylbutanoate.

Conclusion

The product that is formed from the Claisen reaction of the given starting materials by using ${}^{-}\text{OEt}$, $\text{EtOH}$ is shown in Figure 1.

Interpretation Introduction

(b)

Interpretation: The product that is formed from the Claisen reaction of the given starting materials by using ${}^{-}\text{OEt}$, $\text{EtOH}$ is to be drawn.

Concept introduction: Claisen condensation is a reaction in organic chemistry which is used to generate carbon-carbon bond between two ester molecules. These two ester molecules use an alkoxide base in alcohol to form a $\text{β-keto}\text{ester}$.

Answer to Problem 24.40P

The product that is formed from the Claisen reaction of the given starting materials by using ${}^{-}\text{OEt}$, $\text{EtOH}$ is shown below.

Explanation of Solution

The product that is formed from the Claisen reaction of the given starting materials by using ${}^{-}\text{OEt}$, $\text{EtOH}$ is shown as,

Figure 2

In this reaction, acetone is treated with a strong base, $\text{NaOEt}$ which leads to the elimination of a proton from $\text{α}-$ carbon atom. This elimination leads to the formation of an enolate ion. Then, this enolate ion reacts with the given ester, ethyl butanoate to form the desired product, $\text{heptane}-2,4-\text{dione}$.

Conclusion

The product that is formed from the Claisen reaction of the given starting materials by using ${}^{-}\text{OEt}$, $\text{EtOH}$ is shown in Figure 2.

Interpretation Introduction

(c)

Interpretation: The product that is formed from the Claisen reaction of the given starting materials by using ${}^{-}\text{OEt}$, $\text{EtOH}$ is to be drawn.

Concept introduction: Claisen condensation is a reaction in the organic chemistry which is used to generate carbon-carbon bond between two ester molecules. These two ester molecules use an alkoxide base in alcohol to form a $\text{β-keto}\text{ester}$.

Answer to Problem 24.40P

The product that is formed from the Claisen reaction of the given starting materials by using ${}^{-}\text{OEt}$, $\text{EtOH}$ is shown below.

Explanation of Solution

The product that is formed from the Claisen reaction of the given starting materials by using ${}^{-}\text{OEt}$, $\text{EtOH}$ is shown as,

Figure 3

In this reaction, the given compound undergoes internal claisen condensation. The elimination of $\text{α}$-hydrogen atom takes place when it is treated with $\text{NaOEt}$. This elimination leads to the formation of an enolate ion. Then, this enolate ion reacts internally to form the desired product ethyl $3,3$-dimethyl-$2$-oxocyclopentanecarboxylate.

Conclusion

The product that is formed from the Claisen reaction of the given starting materials by using ${}^{-}\text{OEt}$, $\text{EtOH}$ is shown in Figure 3.

Interpretation Introduction

(d)

Interpretation: The product that is formed from the Claisen reaction of the given starting materials by using ${}^{-}\text{OEt}$, $\text{EtOH}$ is to be drawn.

Concept introduction: Claisen condensation is a reaction in organic chemistry which is used to generate carbon-carbon bond between two ester molecules. These two ester molecules use an alkoxide base in alcohol to form a $\text{β-keto}\text{ester}$.

Answer to Problem 24.40P

The product that is formed from the Claisen reaction of the given starting materials by using ${}^{-}\text{OEt}$, $\text{EtOH}$ is shown below.

Explanation of Solution

The product that is formed from the Claisen reaction of the given starting materials by using ${}^{-}\text{OEt}$, $\text{EtOH}$ is shown as,

Figure 4

In this reaction, diethyl carbonate is treated with a strong base, $\text{NaOEt}$ which leads to the elimination of a proton from this compound. This elimination leads to the formation of an enolate ion. Then, this enolate ion reacts with the given ester, ethyl butanoate to form the desired product, $\text{diethyl}2-\text{methylmalonate}$.

Conclusion

The product that is formed from the Claisen reaction of the given starting materials by using ${}^{-}\text{OEt}$, $\text{EtOH}$ is shown in Figure 4.

Interpretation Introduction

(e)

Interpretation: The product that is formed from the Claisen reaction of the given starting materials by using ${}^{-}\text{OEt}$, $\text{EtOH}$ is to be drawn.

Concept introduction: Claisen condensation is a reaction in organic chemistry which is used to generate carbon-carbon bond between two ester molecules. These two ester molecules use an alkoxide base in alcohol to form a $\text{β-keto}\text{ester}$.

Answer to Problem 24.40P

The product that is formed from the Claisen reaction of the given starting materials by using ${}^{-}\text{OEt}$, $\text{EtOH}$ is shown below.

Explanation of Solution

The product that is formed from the Claisen reaction of the given starting materials by using ${}^{-}\text{OEt}$, $\text{EtOH}$ is shown as,

Figure 5

In this reaction, $\text{dihydrofuran}-2-\left(3H\right)-\text{one}$ is treated with a strong base, $\text{NaOEt}$ which leads to the elimination of a proton from this compound. This elimination leads to the formation of an enolate ion. Then, this enolate ion reacts with the given ester, ethyl formate to form the desired product, $2-\text{oxotetrahydrofuran}-3-\text{carbaldehye}$.

Conclusion

The product that is formed from the Claisen reaction of the given starting materials by using ${}^{-}\text{OEt}$, $\text{EtOH}$ is shown in Figure 5.

Interpretation Introduction

(f)

Interpretation: The product that is formed from the Claisen reaction of the given starting materials by using ${}^{-}\text{OEt}$, $\text{EtOH}$ is to be drawn.

Concept introduction: Claisen condensation is a reaction in the organic chemistry which is used to generate carbon-carbon bond between two ester molecules. These two ester molecules use an alkoxide base in alcohol to form a $\text{β-keto}\text{ester}$.

Answer to Problem 24.40P

The product that is formed from the Claisen reaction of the given starting materials by using ${}^{-}\text{OEt}$, $\text{EtOH}$ is given below.

Explanation of Solution

The product that is formed from the Claisen reaction of the given starting materials by using ${}^{-}\text{OEt}$, $\text{EtOH}$ is shown as,

Figure 6

In this reaction, cyclopentanone is treated with a strong base, $\text{NaOEt}$ which leads to the elimination of a proton from this compound. This elimination leads to the formation of an enolate ion. Then, this enolate ion reacts with the given ester, ethyl butanoate to form the desired product, $\text{ethyl}2-\text{oxocyclopentanecarboxylate}$.

Conclusion

The product that is formed from the Claisen reaction of the given starting materials by using ${}^{-}\text{OEt}$, $\text{EtOH}$ is shown in Figure 6.