Chapter 22, Problem 22.88AP

Interpretation Introduction

(a)

Interpretation:

The given reaction is to be completed.

Concept introduction:

An ester is a derivative of carboxylic which is obtained by replacing the $-\text{OH}$ group with $-\text{OR}$ group where $\text{R}$ is any hydrocarbon chain. It is represented by the formula $\text{RCOOR}$. An ester is formed by the reaction of carboxylic acid with alcohol in the presence of an acid catalyst. This reaction is known as Fischer esterification. The reverse of esterification reaction is known as acidic hydrolysis. When ester undergoes hydrolysis in the base, it is known as saponification.

Answer to Problem 22.88AP

The complete reaction is shown below.

Explanation of Solution

The reaction of ethyl acetoacetate with dibromobutane in presence of base and ethanol results in the dialkylation reaction. It forms a cyclic product. This product undergoes hydrolysis reaction followed by decarboxylation reaction gives $1-\text{cyclopentylethanone}$. The given reaction is completed as shown below.

Figure 1

Conclusion

The complete reaction is shown in Figure 1.

Interpretation Introduction

(b)

Interpretation:

The given reaction is to be completed.

Concept introduction:

Lactones are cyclic carboxylic esters analogous to one heteroatom cyclic ring. It is formed by intramolecular esterification reactions. Generally, five of six members lactones are more reactive. Lithium isopropylamine is a strong, non-nucleophilic base.

Answer to Problem 22.88AP

The complete reaction is shown below.

Explanation of Solution

The reaction of lactone which is a cyclic ester with lithium isopropylamide which is used as a base to abstract a proton. It forms an enolate ion which attacks a electrophile methyl iodide. It result in the formation of methyl substituted lactone compound. The given reaction is completed as shown below.

Figure 2

Conclusion

The complete reaction is shown Figure 2.

Interpretation Introduction

(c)

Interpretation:

The given reaction is to be completed.

Concept introduction:

Aryl halides undergo substitution reactions only under drastic conditions. They generally are of two types addition-elimination and elimination reactions. The elimination addition reaction involves a benzyne intermediate. Whereas, in addition, an elimination reaction involves Meisenheimer complex formation.

Answer to Problem 22.88AP

The complete reaction is shown below.

Explanation of Solution

The reaction of $2,4-\text{dinitrochlorobenzene}$ undergoes nucleophilic substitution reaction with a diester methyl dipropionate. This further undergoes hydrolysis and decarboxylation reaction result in the formation of $2-\left(2,4-\text{dinitrophenyl}\right)\text{acetic}\text{acid}$. The complete reaction is shown below.

Figure 3

Conclusion

The complete reaction is shown in Figure 3.

Interpretation Introduction

(d)

Interpretation:

The given reaction is to be completed.

Concept introduction:

The reduction of carbonyl compound is carried out by different reagents. For example ${\text{LiAlH}}_{\text{4}}$ it is used to reduce carboxylic acid and ester also. It is very reactive toward water. It is more powerful reducing agent than ${\text{NaBH}}_{\text{4}}$.

Answer to Problem 22.88AP

The complete reaction is shown below.

Explanation of Solution

The reaction of $1-\text{cyclohexenylethanone}$ undergoes reduction reaction with ${\text{LiAlH}}_{\text{4}}$ followed by hydrolysis reaction. It results in the reduction of the carbonyl group only. The reaction is completed as shown below.

Figure 4

Conclusion

The complete reaction is shown in Figure 4.

Interpretation Introduction

(e)

Interpretation:

The given reaction is to be completed.

Concept introduction:

Michael addition reaction is a nucleophilic addition reaction of an anion to $\alpha ,\beta -$ unsaturated carbonyl compound result in the formation of conjugate addition product. When ester undergoes basic hydrolysis it results in the formation of carboxylate salt and an alcohol which is the reversible step of ester formation.

Answer to Problem 22.88AP

The complete reaction is shown below.

Explanation of Solution

The reaction of an ester with a base result in the abstraction of an acidic proton and form an enolate ion. This enolate ion undergoes $1,4-$ conjugate Michael addition reaction with another ester to form $1,5-$ dicarbonyl compound. It result in the formation of a new $\text{C}-\text{C}$ bond. The reaction is shown below.

Figure 5

Conclusion

The complete reaction is shown in Figure 5.

Interpretation Introduction

(f)

Interpretation:

The given reaction is to be completed.

Concept introduction:

The Knoevenagel condensation reaction is a modification of aldol condensation reaction. In this nucleophilic hydrogen atom adds to carbonyl group followed by dehydration reaction. The compound obtained is known as $\alpha ,\beta -$ unsaturated carbonyl compound.

Answer to Problem 22.88AP

The complete reaction is shown below.

Explanation of Solution

The reaction of benzaldehyde and diethyl malonate in presence of piperdine base which forms an iminium intermediate ion. The reaction in presence of $\text{KCN}/\text{EtOH}$ undergoes knoevenagel condensation reaction which give $\alpha ,\beta$ unsaturated carbonyl compounds. This further on hydrolysis and decarboxylation reaction results in the formation of cinnamic acid as the final product. The reaction is shown below.

Figure 6

Conclusion

The complete reaction is shown in Figure 6.

Interpretation Introduction

(g)

Interpretation:

The given reaction is to be completed.

Concept introduction:

An ester is a derivative of carboxylic which is obtained by replacing the $-\text{OH}$ group with $-\text{OR}$ group where $\text{R}$ is any hydrocarbon chain. It is represented by the formula $\text{RCOOR}$. An ester is formed by the reaction of carboxylic with alcohol in the presence of an acid catalyst. This reaction is known as Fischer Esterification. The reverse of esterification reaction is known as acidic hydrolysis. When ester undergoes hydrolysis in the base, it is known as saponification.

Answer to Problem 22.88AP

The complete reaction is shown below.

Explanation of Solution

The reaction of diethyl malonate in the presence of a base $\text{NaOEt}$ and $\text{EtOH}$ result in the abstraction of proton first and an enolate ion is formed. This enolate ion reacts with given acid chloride gives substituted product with the elimination of the chlorine group. The substituted product on hydrolysis reaction followed by decarboxylation reaction results in the formation of $1,3-$ the carbonyl compound. The reaction is shown below.

Figure 7

Conclusion

The complete reaction is shown in Figure 7.

Interpretation Introduction

(h)

Interpretation:

The given reaction is to be completed.

Concept introduction:

Michael addition reaction is a nucleophilic addition reaction of an anion to $\alpha ,\beta$-unsaturated carbonyl compound result in the formation of conjugate addition product. When ester undergoes basic hydrolysis it results in the formation of carboxylate salt and an alcohol which is the reversible step of ester formation.

Answer to Problem 22.88AP

The complete reaction is shown below.

Explanation of Solution

The reaction of ethylacetoacetate with ethyl acrylate in presence of base ${\text{EtO}}^{-}$ and $\text{EtOH}$ forms an enolate ion. This ion undergo $1,4-$ Michael addition reaction with ethyl acrylate followed by hydrolysis reaction forms $1,5-$ dicarbonyl compound. The reaction is shown below.

Figure 8

Conclusion

The complete reaction is shown in Figure 8.

Interpretation Introduction

(i)

Interpretation:

The given reaction is to be completed.

Concept introduction:

Grignard reagents are organometallic compounds which are prepared using alkyl halides in the presence of magnesium metal in dry ether. These reagents act as strong nucleophiles and bases. Gilman reagent is a lithium and copper reagent. They react with organohalide to replace the halide group. They are used in Corey-House synthesis reaction.

Answer to Problem 22.88AP

The complete reaction is shown below.

Explanation of Solution

The reaction of given dioxolane compound with $\text{Mg, CuBr}$ forms Gilman reagent. It reacts further with cyclohexenone to form an enolate compound. This compound on hydrolysis reaction in the presence of benzene with the removal of protective group results in the formation of $1,7-$ dicarbonyl compound that is $4-\left(3-\text{oxocyclohexyl}\right)\text{butanal}$. The reaction is shown below.

Figure 9

Conclusion

The complete reaction is shown in Figure 9.

Interpretation Introduction

(j)

Interpretation:

The given reaction is to be completed.

Concept introduction:

Grignard reagents are organometallic compounds which are prepared using alkyl halides in the presence of magnesium metal in dry ether. These reagents act as strong nucleophiles and bases. Gilman reagent is a lithium and copper reagent. They react with organohalide to replace the halide group. They are used in Corey-House synthesis reaction.

Answer to Problem 22.88AP

The complete reaction is shown below.

Explanation of Solution

The reaction of unsaturated Grignard reagent in the presence of $\text{CuCl}$ forms Gilman reagent. It undergoes $1,4-$ conjugate addition to the unsaturated carbonyl compound and forms an enolate ion. This ion on hydrolysis reaction results in the formation of unsaturated ketonic compound. The reaction is shown below.

Figure 10

Conclusion

The complete reaction is shown in Figure 10.

Interpretation Introduction

(k)

Interpretation:

The given reaction is to be completed.

Concept introduction:

Grignard reagents are organometallic compounds which are prepared using alkyl halides in the presence of magnesium metal in dry ether. These reagents act as strong nucleophiles and bases. Gilman reagent is a lithium and copper reagent. They react with organohalide to replace the halide group. They are used in Corey-House synthesis reaction.

Answer to Problem 22.88AP

The complete reaction is shown below.

Explanation of Solution

The reaction of the Grignard reagent with $\text{CuCl}$ forms Gilman reagent. This reagent then attacked $\alpha ,\beta -$ unsaturated carbonyl compound followed by hydrolysis reaction forms $1,4-$ addition product of $\alpha ,\beta -$ unsaturated carbonyl compound. The complete reaction is shown below.

Figure 11

Conclusion

The complete reaction is shown in Figure 11.

Interpretation Introduction

(l)

Interpretation:

The given reaction is to be completed.

Concept introduction:

The replacement of hydrogen atom attached to a carbon atom of electron-rich benzene ring by an incoming electrophile is known as electrophilic aromatic substitution reaction. The rate of electrophilic aromatic substitution reaction depends on the substituted group on the aromatic ring.

Answer to Problem 22.88AP

The complete reaction is shown below.

Explanation of Solution

The electrophilic substitution reaction of benzene with $\alpha ,\beta -$ unsaturated carbonyl aromatic compound in presence of Lewis acid forms electrophilic substituted product. Benzene ring is substituted at the double bond position. The reaction is shown below.

Figure 12

Conclusion

The complete reaction is shown in Figure 12.

Interpretation Introduction

(m)

Interpretation:

The given reaction is to be completed.

Concept introduction:

The Claisen condensation reaction in which two esters or one ester and a carbonyl compound react together to form $\beta$ ketoester and $\beta$-diketone compound in the presence of a base. The product formed $\beta$ ketoester is an unstable compound than the ester that is why a base is used to shift the reaction equilibrium.

Answer to Problem 22.88AP

The complete reaction is shown below.

Explanation of Solution

The reaction of diethyl malonate in the presence a base forms an enolate ion. This attacked on another ester molecule and result in the formation of $\beta -$ ketoester. This reaction is a type of Claisen condensation reaction This compound undergoes hydrolysis followed by decarboxylation reaction forms $\beta -$ keto carboxylic acid compound. The reaction is shown below.

Figure 13

Conclusion

The complete reaction is shown in Figure 13.