Chapter 22, Problem 22.82AP

Interpretation Introduction

(a)

Interpretation:

The synthesis of $3-\text{methylcyclopentanol}$ from the reaction of $2-\text{cyclopentenone}$ is to be stated.

Concept introduction:

In organic chemistry, the class of functional group which is derived from conjugated diene by replacing one double bond with a carbonyl group is known as enone. The dienone compound is in conjugation to each other.

Answer to Problem 22.82AP

The synthesis of $3-\text{methylcyclopentanol}$ from the reaction of $2-\text{cyclopentenone}$ is shown below.

Explanation of Solution

The reaction of $2-\text{cyclopentenone}$ with halogen acids, gives addition product. This undergoes Wurtz reaction followed by reduction reaction with ${\text{NaBH}}_{\text{4}}$, and forms the desired product. The synthesis of $3-\text{methylcyclopentanol}$ from the reaction of $2-\text{cyclopentenone}$ is shown below.

Figure 1

Conclusion

The synthesis of $3-\text{methylcyclopentanol}$ from the reaction of $2-\text{cyclopentenone}$ is shown in Figure 1.

Interpretation Introduction

(b)

Interpretation:

The synthesis of $1,3,3-\text{trimethylcyclohexanol}$ from $3-\text{methylcyclohexenone}$ is to be stated.

Concept introduction:

In organic chemistry, the class of functional group which is derived from conjugated diene by replacing one double bond with a carbonyl group. The dienone compound is in conjugation to each other.

Answer to Problem 22.82AP

The synthesis of $1,3,3-\text{trimethylcyclohexanol}$ from $\text{3-methyl-2-cyclohexenone}$ is shown below.

Explanation of Solution

The reaction of $\text{3-methyl-2-cyclohexenone}$ with Grignard reagent gives $\text{1, 3-dimethylcyclohex-2-enol}$ followed. Alkylation of $\text{1, 3-dimethylcyclohex-2-enol}$ by ${\text{NaBH}}_{\text{4}}$ gives the desired product. The synthesis of $1,3,3-\text{trimethylcyclohexanol}$ from $3-\text{methylcyclohexenone}$ is shown below.

Figure 2

Conclusion

The synthesis of $1,3,3-\text{trimethylcyclohexanol}$ from $\text{3-methyl-2-cyclohexenone}$ is shown in Figure 2.

Interpretation Introduction

(c)

Interpretation:

The synthesis of $2-\text{benzylcyclohexanone}$ from diethyl heptanedioate is to be stated.

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 22.82AP

The synthesis of $2-\text{benzylcyclohexanone}$ from diethyl heptanedioate is shown below.

Explanation of Solution

Diethyl heptanedioate in presence of ${\text{NaOEt/H}}_{\text{3}}{\text{O}}^{\text{+}}$ results in the formation of ethyl $2$-oxocyclohexanecarboxylic acid. Ethyl $2$-oxocyclohexanecarboxylic acid reacts with $\text{NaOEt}$ and ${\text{PhCH}}_{\text{2}}\text{Br}$ to form ethyl $1$-benzyl-$2$-oxocyclohexanecarboxylic acid which on reaction with ${\text{NaOH, H}}_{\text{2}}\text{O}$ and ${\text{H}}_{\text{3}}{\text{O}}^{\text{+}}\text{,}\text{heat}$ results in the formation of desired product, $2$-benzylcyclohexanone. The synthesis of $2-\text{benzylcyclohexanone}$ from diethyl heptanedioate is shown below.

Figure 3

Conclusion

The synthesis of $2-\text{benzylcyclohexanone}$ from diethyl heptanedioate is shown in Figure 3.

Interpretation Introduction

(d)

Interpretation:

The synthesis of $2,2-\text{dimethylpropane}-1,3-\text{diol}$ from diethyl malonate is to be stated.

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 22.82AP

The synthesis of $2,2-\text{dimethylpropane}-1,3-\text{diol}$ from diethyl malonate is shown below.

Explanation of Solution

The reaction of diethyl malonate in presence of base and then ${\text{CH}}_{\text{3}}\text{I}$ forms methyl monosusbtituted product. It further reacts with a base and then with ${\text{CH}}_{\text{3}}\text{I}$ forms methyl disubstituted product. Then it undergoes reduction reaction which leds to the formation of the desired product. The synthesis of $2,2-\text{dimethylpropane}-1,3-\text{diol}$ from diethyl malonate is shown below.

Figure 4

Conclusion

The synthesis of $2,2-\text{dimethylpropane}-1,3-\text{diol}$ from diethyl malonate is shown in Figure 4.

Interpretation Introduction

(e)

Interpretation:

The synthesis of $4-\text{aminobutanol}$ from ethyl acrylate is to be stated.

Concept introduction:

An ester is a derivative of carboxylic acid 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 22.82AP

The synthesis of $4-\text{aminobutanol}$ from ethyl acrylate is shown below.

Explanation of Solution

The reaction of ethyl acrylate with ammonia forms amide derivative. It undergoes reduction reaction with ${\text{LiAlH}}_{\text{4}}$ followed by addition reaction with $\text{HBr}$ in peroxides which forms $4-\text{bromobutan}-1-\text{amine}$. Then it reacts with potassium cyanide followed by hydrolysis and decarboxylation. It results in the formation of $4-\text{aminobutanol}$. The synthesis of $4-\text{aminobutanol}$ from ethyl acrylate is shown below.

Figure 5

Conclusion

The synthesis of $4-\text{aminobutanol}$ from ethyl acrylate is shown in Figure 5.

Interpretation Introduction

(f)

Interpretation:

The synthesis of $N^1,N^1-\text{diethylpropane}-1,3-\text{diamine}$ from acrylonitrile is to be stated.

Concept introduction:

In organic chemistry, the compound with the molecular formula ${\text{CH}}_{\text{2}}=\text{CH}-\text{C}\equiv \text{N}$ is known as acrylonitrile. It shows similar chemical properties to alkene and cyanide compounds. It is used to synthesis polyacrylonitrile polymer.

Answer to Problem 22.82AP

The synthesis of $N^1,N^1-\text{diethylpropane}-1,3-\text{diamine}$ from acrylonitrile is shown below.

Explanation of Solution

The reaction of acrylonitrile with ${\text{LiAlH}}_{\text{4}}$ followed by addition reaction with $\text{HBr}$ in peroxides forms $3-\text{bromopropanamine}$. Then it reacts with $\text{KCN}$ followed by ${\text{LiAlH}}_{\text{4}}$ and then amine alkylation reaction. it forms the desired product. The synthesis of $N^1,N^1-\text{diethylpropane}-1,3-\text{diamine}$ from acrylonitrile is shown below.

Figure 6

Conclusion

The synthesis of $N^1,N^1-\text{diethylpropane}-1,3-\text{diamine}$ from acrylonitrile is shown in Figure 6.

Interpretation Introduction

(g)

Interpretation:

The synthesis of $2-\text{phenylbutanoic}\text{}\text{acid}$ from phenylacetic acid is to be stated.

Concept introduction:

Carboxylic acid is a class of organic compound contains a $-\text{COOH}$ group attached with a hydrocarbon chain. They occur widely in nature that includes amino acid, acetic acid (vinegar) and so on. Deprotonation of carboxylic acid gives carboxylate anion which is mostly present in soaps. The name of these compounds ends with a suffix $-oicacid$ or $-icacid$.

Answer to Problem 22.82AP

The synthesis of $2-\text{phenylbutanoic}\text{}\text{acid}$ from phenylacetic acid is shown below.

Explanation of Solution

Esterification of phenylacetic acid forms ethyl $2-$ phenylacetate. Then it reacts with sodium ethoxide and ethyl iodide to form ethyl $2-$ phenylbutanoate. It undergoes saponification followed by acidic treatment to form the desired product. The synthesis of $2-\text{phenylbutanoic}\text{}\text{acid}$ from phenylacetic acid is shown below.

Figure 7

Conclusion

The synthesis of $2-\text{phenylbutanoic}\text{}\text{acid}$ from phenylacetic acid is shown in Figure 7.

Interpretation Introduction

(h)

Interpretation:

The synthesis of $1,3-\text{diphenylbutan}-1-\text{one}$ from acetophenone is to be stated.

Concept introduction:

In Aldol condensation reaction, the base abstracts an acidic proton from the $\text{α}$ carbon atom to form enolate. This enolate or enol reacts with carbonyl compound that leads to the formation of $\text{β}$-hydroxyaldehyde or $\text{β}$-hydroxyketone which on further dehydration gives the conjugated enone.

Answer to Problem 22.82AP

The synthesis of $1,3-\text{diphenylbutan}-1-\text{one}$ from acetophenone is shown below.

Explanation of Solution

The reaction of acetophenone in presence of base abstracts a $\alpha -$ proton. It attacked on another acetophenone followed by hydrolysis it forms $\beta -$ hydroxyaldehyde. It undergoes dehydration reaction followed by hydrogenation forms the desired product. The synthesis of $1,3-\text{diphenylbutan}-1-\text{one}$ from acetophenone is shown below.

Figure 8

Conclusion

The synthesis of $1,3-\text{diphenylbutan}-1-\text{one}$ from acetophenone is shown in Figure 8.

Interpretation Introduction

(i)

Interpretation:

The synthesis of deuterium substituted diphenylethanol from phenylacetic acid is to be stated.

Concept introduction:

Carboxylic acid is a class of organic compound that contains a $-\text{COOH}$ group attached with a hydrocarbon chain. They occur widely in nature that includes amino acid, acetic acid (vinegar) and so on. Deprotonation of carboxylic acid gives carboxylate anion which is mostly present in soaps. The name of these compounds ends with a suffix $-oicacid$ or $-icacid$.

Answer to Problem 22.82AP

The synthesis of di-deuterium substituted diphenyl ethanol from phenylacetic acid is shown below.

Explanation of Solution

Reaction of $\text{2}$-phenylacetic acid with ethanol and acid gives ethyl $\text{2}$-phenylacetate. It reacts with heavy water in the presence of ${\text{D}}_3{\text{O}}^{+}$ to undergo a deuterium exchange reaction to form deutrated ethyl $\text{2}$-phenylacetate. It undergoes reduction to form deutrated alcohol. This alcohol undergoes oxidation in the presence of PCC to form a deutrated aldehyde which on reaction with phenyl magnesium bromide gives the desired product. The synthesis of deuterium substituted diphenyl ethanol from phenylacetic acid is shown below.

Figure 9

Conclusion

The synthesis of deuterium substituted diphenyl ethanol from phenylacetic acid is shown in Figure 9.

Interpretation Introduction

(j)

Interpretation:

The synthesis of tetra-deuterium substituted product from cyclohexanone is to be stated.

Concept introduction:

In organic chemistry, the carbonyl compound is a class of functional group which contains a $\text{C}=\text{O}$ group. They are of two types, aldehyde $-\text{CHO}$ and ketone $\text{RC}=\text{OR}$. They are the oxidized product of alcohol. Tollens reagent test confirms the presence of aldehyde group only.

Answer to Problem 22.82AP

The synthesis of tetra-deuterium substituted product from cyclohexanone is shown below.

Explanation of Solution

The reaction of cyclohexanone with ${\text{D}}_{\text{2}}\text{O}/{\text{D}}_{\text{3}}{\text{O}}^{\text{+}}$ followed by Wittig reaction forms the desired product. The synthesis of tetra-deuterium substituted product from cyclohexanone is shown below.

Figure 10

Conclusion

The synthesis of tetra-deuterium substituted from cyclohexanone is shown in Figure 10.

Interpretation Introduction

(k)

Interpretation:

The synthesis of ${\text{CH}}_{\text{3}}\text{O}-\text{Ph}-\text{CO}-{\text{CH}}_{\text{2}}-\text{O}-\text{Ph}$ from acetyl chloride is to be stated.

Concept introduction:

Friedel Craft acylation is an electrophilic aromatic substitution reaction. In this reaction, the synthesis of the monoacylated product takes place from the reaction between aromatic rings and acyl chlorides. The organic reaction in which an organohalide is reacted with alcohols or phenols to form ethers is Willamson synthesis reaction.

Answer to Problem 22.82AP

The synthesis of ${\text{CH}}_{\text{3}}\text{O}-\text{Ph}-\text{CO}-{\text{CH}}_{\text{2}}-\text{O}-\text{Ph}$ from acetyl chloride is shown below.

Explanation of Solution

The reaction of phenol with methyl halide forms methylphenyl ether. It reacts with acetyl chloride followed by chlorination in sunlight. Then it reacts with phenol to give the desired product. The synthesis of ${\text{CH}}_{\text{3}}\text{O}-\text{Ph}-\text{CO}-{\text{CH}}_{\text{2}}-\text{O}-\text{Ph}$ from acetyl chloride is shown below.

Figure 11

Conclusion

The synthesis of ${\text{CH}}_{\text{3}}\text{O}-\text{Ph}-\text{CO}-{\text{CH}}_{\text{2}}-\text{O}-\text{Ph}$ from acetyl chloride is shown in Figure 11.

Interpretation Introduction

(l)

Interpretation:

The synthesis of $4-\text{methylnonan}-5-\text{one}$ from diethyl malonate is to be stated.

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 22.82AP

The synthesis of $4-\text{methylnonan}-5-\text{one}$ from diethyl malonate is shown below.

Explanation of Solution

Methylation of diethyl malonate in the presence of sodium ethoxide and ${\text{CH}}_{\text{3}}\text{I}$ gives diethyl $\text{2}$-methylmalonate. The conjugate addition of enolate formed by the reaction of diethyl $\text{2}$-methylmalonate with sodium ethoxide on $4$-methylhept-$1$-en-$3$-one gives a diester compound. It undergoes saponification followed by acidic treatment to give a diacid. This diacid undergoes decarboxylation under heating conditions to give the desired product. The synthesis of $4-\text{methylnonan}-5-\text{one}$ from diethyl malonate is shown below.

Figure 12

Conclusion

The synthesis of $4-\text{methylnonan}-5-\text{one}$ from diethyl malonate is shown in Figure 12.

Interpretation Introduction

(m)

Interpretation:

The synthesis of $\text{3}-\left(2-\text{oxocyclopentyl}\right)\text{propanoic}\text{acid}$ from $\text{ethyl}2-\text{oxocyclopentanecarboxylate}$ is to be stated.

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 22.82AP

The synthesis of $\text{3}-\left(2-\text{oxocyclopentyl}\right)\text{propanoic}\text{acid}$ from diethyl malonate is shown below.

Explanation of Solution

The hydrolysis reaction of $\text{ethyl}2-\text{oxocyclopentanecarboxylate}$ followed by decarboxylation reaction forms cyclopentanone which reacts with ethyl iodide in $\text{NaH}/\text{THF}$ followed by chlorination reaction. Further, it reacts with $\text{KCN}$ that on hydrolysis reaction forms the desired product. The synthesis of $\text{3}-\left(2-\text{oxocyclopentyl}\right)\text{propanoic}\text{acid}$ from $\text{ethyl}2-\text{oxocyclopentanecarboxylate}$ is shown below.

Figure13

Conclusion

The synthesis of $\text{3}-\left(2-\text{oxocyclopentyl}\right)\text{propanoic}\text{acid}$ from diethyl malonate is shown in Figure 13.