Chapter 21, Problem 21.86P

Interpretation Introduction

(a)

Interpretation:

The synthesis of ethyl acetate using only acetic acid as the source of carbon is to be proposed.

Concept introduction:

A carboxylic acid is a fairly stable compound and does not readily undergo nucleophilic addition to form a new $\text{C}-\text{C}$ bond. However, it can be converted to a much less stable derivative like acid chloride using inorganic reagents such as ${\text{SOCl}}_{\text{2}}$. Acid chloride being the least stable acid derivative readily undergoes a variety of nucleophilic addition or substitution reactions to form a new $\text{C}-\text{C}$ bond involving its carbonyl carbon.

Answer to Problem 21.86P

Ethyl acetate can be synthesized using only acetic acid as the source of carbon in the following way.

Explanation of Solution

The synthesis of ethyl acetate from acetic acid can be designed using retrosynthetic analysis.

The transform is an undoing of nucleophilic substitution at the carbonyl carbon.

In the forward direction, it can be achieved by reacting to acyl chloride with ethanol, both of which derived from acetic acid. The first one can be synthesized by reacting acetic acid with ${\text{SOCl}}_{\text{2}}$. Ethanol can be obtained by reducing acetic acid with ${\text{LiAlH}}_4$.

Thus the synthesis of ethyl acetate can be carried out as

Conclusion

The synthesis of ethyl acetate was proposed based on conversion of acetic acid to acid chloride followed by nucleophilic addition.

Interpretation Introduction

(b)

Interpretation:

The synthesis of $\text{butan-2-ol}$ using only acetic acid as the source of carbon is to be proposed.

Concept introduction:

A carboxylic acid is a fairly stable compound and does not readily undergo nucleophilic addition to form a new $\text{C}-\text{C}$ bond. However, it can be converted to a much less stable derivative like acid chloride using inorganic reagents such as ${\text{SOCl}}_{\text{2}}$. Acid chloride being the least stable acid derivative readily undergoes a variety of nucleophilic addition reactions to form a new $\text{C}-\text{C}$ bond involving its carbonyl carbon.

Answer to Problem 21.86P

$\text{Butan-2-ol}$ can be synthesized using only acetic acid as the source of carbon as

Explanation of Solution

$\text{Butan-2-ol}$ is a four carbon alcohol. Retrosynthetic analysis suggests the undoing of the C2-C3 bond. The corresponding precursors can be acid chloride and lithium diethyl cuprate.

The acid chloride can be obtained by treating acetic acid with ${\text{SOCl}}_{\text{2}}$. Lithium diethylcuprate can be obtained by reduction of the acid to ethanol followed by conversion to ethyl bromide using ${\text{PBr}}_3$, treatment of the bromide with lithium and finally with copper(I) iodide. The reaction between acid chloride and lithium diethylcuprate will yield butanone which can be reduced with ${\text{NaBH}}_{\text{4}}$ to $\text{butan-2-ol}$.

Conclusion

The synthesis of $\text{butan-2-ol}$ was proposed based on the conversion of acetic acid to acid chloride followed by nucleophilic addition and reduction.

Interpretation Introduction

(c)

Interpretation:

The synthesis of $\text{3-methylpentan-3-ol}$ using only acetic acid as the source of carbon is to be proposed.

Concept introduction:

A carboxylic acid is a fairly stable compound and does not readily undergo nucleophilic addition to form a new $\text{C}-\text{C}$ bond. However, it can be converted to a much less stable derivative like acid chloride using inorganic reagents such as ${\text{SOCl}}_{\text{2}}$. Acid chloride being the least stable acid derivative readily undergoes a variety of nucleophilic addition reactions to form a new $\text{C}-\text{C}$ bond involving its carbonyl carbon.

Answer to Problem 21.86P

$\text{3-Methylpentan-3-ol}$ can be synthesized using only acetic acid as the source of carbon as

Explanation of Solution

$\text{3-Methylpentan-3-ol}$ is a six-carbon compound. Therefore, its synthesis from acetic acid will involve three moles of acetic acid.

The first transform breaks up the bond between one ethyl group and the carbon bonded to the OH group. This fragment can come from ethyl lithium while the larger one would be butanone. Butanone, in turn, can be derived from ethyl acetate and ethyl lithium. Thus, the synthesis in the forward direction can be carried out as

Conclusion

The synthesis of $\text{3-methylpentan-3-ol}$ was proposed based on the conversion of acetic acid to ethyl acetate followed by nucleophilic addition.

Interpretation Introduction

(d)

Interpretation:

The synthesis of $\text{butan-2-one}$ using only acetic acid as the source of carbon is to be proposed.

Concept introduction:

A carboxylic acid is a fairly stable compound and does not readily undergo nucleophilic addition to form a new $\text{C}-\text{C}$ bond. However, it can be converted to a much less stable derivative like acid chloride using inorganic reagents such as ${\text{SOCl}}_{\text{2}}$. Acid chloride being the least stable acid derivative readily undergoes a variety of nucleophilic addition reactions to form a new $\text{C}-\text{C}$ bond involving its carbonyl carbon.

Answer to Problem 21.86P

$\text{Butan-2-one}$ can be synthesized using only acetic acid as the source of carbon as

Explanation of Solution

$\text{Butan-2-one}$ is a four carbon compound. It can be synthesized with two moles of acetic acid. One mole is reduced with ${\text{LiAlH}}_4$ to ethanol. Ethanol is then converted to ethyl bromide with ${\text{PBr}}_3$. Reacting ethyl bromide with lithium and then copper(I) iodide will provide the nucleophile needed to add to the acid chloride. The acid chloride is derived from acetic acid by treatment with ${\text{SOCl}}_{\text{2}}$.

Thus, $\text{butan-2-one}$ can be synthesized as

Conclusion

The synthesis of $\text{butan-2-one}$ was proposed based on conversion of acetic acid to acid chloride followed by nucleophilic addition.

Interpretation Introduction

(e)

Interpretation:

The synthesis of ethanamine using only acetic acid as the source of carbon is to be proposed.

Concept introduction:

A carboxylic acid is a fairly stable compound and does not readily undergo nucleophilic addition to form a new $\text{C}-\text{C}$ bond. However, it can be converted to a much less stable derivative like acid chloride using inorganic reagents such as ${\text{SOCl}}_{\text{2}}$. Acid chloride being the least stable acid derivative readily undergoes a variety of nucleophilic addition reactions to form a new $\text{C}-\text{C}$ bond involving its carbonyl carbon.

Answer to Problem 21.86P

Ethanamine can be synthesized using only acetic acid as the source of carbon as

Explanation of Solution

Ethanamine has only two carbons, the same as acetic acid. So it can be synthesized using only one mole of acetic acid. The first reaction is the conversion of the acid to acid chloride. The acid chloride can then be treated with ammonia to produce acetamide. The amide on reduction with ${\text{LiAlH}}_4$ followed by acid workup will produce ethanamine.

Conclusion

The synthesis of ethanamine was proposed based on the conversion of acetic acid to acid chloride followed by nucleophilic substitution and reduction.

Interpretation Introduction

(f)

Interpretation:

The synthesis of $\text{N-ethylacetamide}$ using only acetic acid as the source of carbon is to be proposed.

Concept introduction:

A carboxylic acid is a fairly stable compound and does not readily undergo nucleophilic addition to form a new $\text{C}-\text{C}$ bond. However, it can be converted to a much less stable derivative like acid chloride using inorganic reagents such as ${\text{SOCl}}_{\text{2}}$. Acid chloride being the least stable acid derivative readily undergoes a variety of nucleophilic addition reactions to form a new $\text{C}-\text{C}$ bond involving its carbonyl carbon.

Answer to Problem 21.86P

$\text{N-ethylacetamide}$ can be synthesized using only acetic acid as the source of carbon as

Explanation of Solution

$\text{N-ethylacetamide}$ is a four carbon compound. It can be synthesized using two moles of acetic acid, One mole can be converted to ethanamine as shown in part (e). The other one can be converted to acid chloride. The reaction between acid chloride and ethanamine will then yield $\text{N-ethylacetamide}$.

Conclusion

The synthesis of $\text{N-ethylacetamide}$ was proposed based on the conversion of acetic acid to acid chloride followed by nucleophilic substitution.

Interpretation Introduction

(g)

Interpretation:

The synthesis of $\text{N, N-diethylacetamide}$ using only acetic acid as the source of carbon is to be proposed.

Concept introduction:

A carboxylic acid is a fairly stable compound and does not readily undergo nucleophilic addition to form a new $\text{C}-\text{C}$ bond. However, it can be converted to a much less stable derivative like acid chloride using inorganic reagents such as ${\text{SOCl}}_{\text{2}}$. Acid chloride being the least stable acid derivative readily undergoes a variety of nucleophilic addition reactions to form a new $\text{C}-\text{C}$ bond involving its carbonyl carbon.

Answer to Problem 21.86P

$\text{N, N-diethylacetamide}$ can be synthesized using only acetic acid as the source of carbon as

Explanation of Solution

$\text{N, N-diethylacetamide}$ is a six carbon compound and will require three moles of acetic acid. The reaction can start with the synthesis of $\text{N-ethylacetamide}$ as shown in part (f). Reducing this with ${\text{LiAlH}}_{\text{4}}$ will produce diethylamine. Diethylamine can serve as the nucleophile in a reaction with acid chloride derived from acetic acid. The substitution of the chloride will form the desired product.

Conclusion

The synthesis of $\text{N, N-diethylacetamide}$ was proposed based on conversion of acetic acid to acid chloride followed by nucleophilic addition.