Chapter 27, Problem 27.43AP

Interpretation Introduction

(a)

Interpretation:

The structure of the product expected when valine would react with ${\text{H}}_{\text{2}}{\text{SO}}_{\text{4}}$ as catalyst in ethanol is to be predicted. The structure of the product expected when proline would react with ${\text{H}}_{\text{2}}{\text{SO}}_{\text{4}}$ as catalyst in ethanol is to be predicted.

Concept introduction:

The chemical compounds in which carbon is bonded with the acidic and basic group along with hydrocarbon side chain are known as amino acids. The amino acids are classified into acidic, basic, polar, non-polar, essential, and non-essential categories. The three-word abbreviation or one-word abbreviation is used for amino acids.

Answer to Problem 27.43AP

The structure of the product expected when valine would react with ${\text{H}}_{\text{2}}{\text{SO}}_{\text{4}}$ as catalyst in ethanol is shown below.

The structure of the product expected when proline would react with ${\text{H}}_{\text{2}}{\text{SO}}_{\text{4}}$ as catalyst in ethanol is shown below.

Explanation of Solution

The valine has a carboxylic group in it. This carboxylic group can undergo esterification with ethanol in the presence of sulfuric acid. The corresponding chemical reaction is shown below.

Figure 1

The proline has a carboxylic group in it. This carboxylic group can undergo esterification with ethanol in the presence of sulfuric acid. The corresponding chemical reaction is shown below.

Figure 2

Conclusion

The structure of the product expected when valine would react with ${\text{H}}_{\text{2}}{\text{SO}}_{\text{4}}$ as catalyst in ethanol is shown in Figure 1. The structure of the product expected when proline would react with ${\text{H}}_{\text{2}}{\text{SO}}_{\text{4}}$ as catalyst in ethanol is shown in Figure 2.

Interpretation Introduction

(b)

Interpretation:

The structure of the product expected when valine would react with benzoyl chloride and ${\text{Et}}_{\text{3}}\text{N}$ is to be predicted. The structure of the product expected when proline would react with benzoyl chloride and ${\text{Et}}_{\text{3}}\text{N}$ is to be predicted.

Concept introduction:

The chemical compounds in which carbon is bonded with the acidic and basic group along with hydrocarbon side chain are known as amino acids. The amino acids are classified into acidic, basic, polar, non-polar, essential, and non-essential categories. The three-word abbreviation or one-word abbreviation is used for amino acids.

Answer to Problem 27.43AP

The structure of the product expected when valine would react with benzoyl chloride and is shown below.

The structure of the product expected when proline would react with benzoyl chloride and ${\text{Et}}_{\text{3}}\text{N}$ is shown below.

Explanation of Solution

The valine has a basic amine group in it. This group can react with benzoyl chloride to form the amide bond. The corresponding chemical reaction is shown below.

Figure 3

The proline has a basic amine group in it. This group can react with benzoyl chloride to form amide bond. The corresponding chemical reaction is shown below.

Figure 4

Conclusion

The structure of the product expected when valine would react with benzoyl chloride and ${\text{Et}}_{\text{3}}\text{N}$ is shown in Figure 3.

The structure of the product expected when proline would react with benzoyl chloride and ${\text{Et}}_{\text{3}}\text{N}$ is shown in Figure 4.

Interpretation Introduction

(c)

Interpretation:

The structure of the product expected when valine would react with an aqueous $\text{HCl}$ solution is to be predicted. The structure of the product expected when proline would react with an aqueous $\text{HCl}$ solution is to be predicted.

Concept introduction:

The chemical compounds in which carbon is bonded with the acidic and basic group along with hydrocarbon side chain are known as amino acids. The amino acids are classified into acidic, basic, polar, non-polar, essential, and non-essential categories. The three-word abbreviation or one-word abbreviation is used for amino acids.

Answer to Problem 27.43AP

The structure of the product expected when valine would react with an aqueous $\text{HCl}$ solution is shown below.

The structure of the product expected when proline would react with an aqueous $\text{HCl}$ solution is shown below.

Explanation of Solution

The valine has a basic amine group in it. This amine group can react with acid to form an ammonium base. The corresponding chemical reaction is shown below.

Figure 5

The proline has a basic amine group in it. This amine group can react with acid to form an ammonium base. The corresponding chemical reaction is shown below.

Figure 6

Conclusion

The structure of the product expected when valine would react with an aqueous $\text{HCl}$ solution is shown in Figure 5.

The structure of the product expected when proline would react with an aqueous $\text{HCl}$ solution is shown in Figure 6.

Interpretation Introduction

(d)

Interpretation:

The structure of the product expected when valine would react with an aqueous $\text{NaOH}$ solution is to be predicted. The structure of the product expected when proline would react with an aqueous $\text{NaOH}$ solution is to be predicted.

Concept introduction:

The chemical compounds in which carbon is bonded with the acidic and basic group along with hydrocarbon side chain are known as amino acids. The amino acids are classified into acidic, basic, polar, non-polar, essential, and non-essential categories. The three-word abbreviation or one-word abbreviation is used for amino acids.

Answer to Problem 27.43AP

The structure of the product expected when valine would react with an aqueous $\text{NaOH}$ solution is shown below.

The structure of the product expected when proline would react with an aqueous $\text{NaOH}$ solution is shown below.

Explanation of Solution

The valine has an acidic carboxylic group in it. This group can react with a base such as sodium hydroxide to form a sodium salt of carboxylic acid. The corresponding chemical reaction is shown below.

Figure 7

The proline has an acidic carboxylic group in it. This group can react with a base such as sodium hydroxide to form a sodium salt of carboxylic acid. The corresponding chemical reaction is shown below.

Figure 8

Conclusion

The structure of the product expected when valine would react with an aqueous $\text{NaOH}$ solution is shown in Figure 7.

The structure of the product expected when proline would react with an aqueous $\text{NaOH}$ solution is shown in Figure 8.

Interpretation Introduction

(e)

Interpretation:

The structure of the product expected when valine would react with aqueous benzaldehyde and $\text{NaCN}$ with the supply of heat is to be predicted. The structure of the product expected when proline would react with aqueous benzaldehyde and $\text{NaCN}$ with the supply of heat is to be predicted.

Concept introduction:

The chemical compounds in which carbon is bonded with the acidic and basic group along with hydrocarbon side chain are known as amino acids. The amino acids are classified into acidic, basic, polar, non-polar, essential, and non-essential categories. The three-word abbreviation or one-word abbreviation is used for amino acids.

Answer to Problem 27.43AP

The structure of the product expected when valine would react with aqueous benzaldehyde and $\text{NaCN}$ with the supply of heat is shown below.

The structure of the product expected when proline would react with aqueous benzaldehyde and $\text{NaCN}$ with the supply of heat is shown below.

Explanation of Solution

The valine has a basic group in it. This group can be attacked by the benzaldehyde in the presence of sodium cyanide to form the final product. The corresponding chemical reaction is shown below.

Figure 9

The proline has a basic group in it. This group can be attacked by the benzaldehyde in the presence of sodium cyanide to form the final product. The corresponding chemical reaction is shown below.

Figure 10

Conclusion

The structure of the product expected when valine would react with aqueous benzaldehyde and $\text{NaCN}$ with the supply of heat is shown in Figure 9.

The structure of the product expected when proline would react with aqueous benzaldehyde and $\text{NaCN}$ with the supply of heat is shown in Figure 10.

Interpretation Introduction

(f)

Interpretation:

The structure of the product expected when valine would react with aqueous Fmoc-$\text{NHS}$ ester, ${\text{Na}}_{\text{2}}{\text{CO}}_{\text{3}}$ and aqueous $1,2-\text{dimethoxyethane}$ followed by neutralizing with ${\text{H}}_{\text{3}}{\text{O}}^{+}$ is to be predicted. The structure of the product expected when proline would react with aqueous Fmoc-$\text{NHS}$ ester, ${\text{Na}}_{\text{2}}{\text{CO}}_{\text{3}}$ and aqueous followed by neutralizing with ${\text{H}}_{\text{3}}{\text{O}}^{+}$ is to be predicted.

Concept introduction:

The chemical compounds in which carbon is bonded with the acidic and basic group along with hydrocarbon side chain are known as amino acids. The amino acids are classified into acidic, basic, polar, non-polar, essential, and non-essential categories. The three-word abbreviation or one-word abbreviation is used for amino acids.

Answer to Problem 27.43AP

The structure of the product expected when valine would react with aqueous Fmoc-$\text{NHS}$ ester, ${\text{Na}}_{\text{2}}{\text{CO}}_{\text{3}}$ and aqueous $1,2-\text{dimethoxyethane}$ followed by neutralizing with ${\text{H}}_{\text{3}}{\text{O}}^{+}$ is shown below.

The structure of the product expected when proline would react with aqueous Fmoc-$\text{NHS}$ ester, ${\text{Na}}_{\text{2}}{\text{CO}}_{\text{3}}$ and aqueous $1,2-\text{dimethoxyethane}$ followed by neutralizing with ${\text{H}}_{\text{3}}{\text{O}}^{+}$ is shown below.

Explanation of Solution

The valine has an amine group. This group can be protected by the reaction of valine with aqueous Fmoc-$\text{NHS}$ ester, ${\text{Na}}_{\text{2}}{\text{CO}}_{\text{3}}$ and aqueous $1,2-\text{dimethoxyethane}$ followed by neutralization with ${\text{H}}_{\text{3}}{\text{O}}^{+}$. The corresponding chemical reaction is shown below.

Figure 11

The proline has an amine group. This group can be protected by the reaction of proline with aqueous Fmoc-$\text{NHS}$ ester, ${\text{Na}}_{\text{2}}{\text{CO}}_{\text{3}}$ and aqueous $1,2-\text{dimethoxyethane}$ followed by neutralization with ${\text{H}}_{\text{3}}{\text{O}}^{+}$. The corresponding chemical reaction is shown below.

Figure 12

Conclusion

The structure of the product expected when valine would react with aqueous Fmoc-$\text{NHS}$ ester, ${\text{Na}}_{\text{2}}{\text{CO}}_{\text{3}}$ and aqueous $1,2-\text{dimethoxyethane}$ by neutralizing with ${\text{H}}_{\text{3}}{\text{O}}^{+}$ is shown in Figure 11.

The structure of the product expected when proline would react with aqueous Fmoc-$\text{NHS}$ ester, ${\text{Na}}_{\text{2}}{\text{CO}}_{\text{3}}$ and aqueous $1,2-\text{dimethoxyethane}$ followed by neutralizing with ${\text{H}}_{\text{3}}{\text{O}}^{+}$ is shown in Figure 12.

Interpretation Introduction

(g)

Interpretation:

The structure of the product expected when the given derivative of valine would react with $\text{DIC}/\text{HOBt}$ followed with the addition of glycine butyl ester is to be predicted. The structure of the product expected when the given derivative of proline would react with $\text{DIC}/\text{HOBt}$ followed with the addition of glycine butyl ester is to be predicted.

Concept introduction:

The chemical compounds in which carbon is bonded with the acidic and basic group along with hydrocarbon side chain are known as amino acids. These functional groups can be protected by different reagent to synthesize peptide chains. The protecting groups can be removed by hydrolysis.

Answer to Problem 27.43AP

The structure of the product expected when the given derivative of valine would react with $\text{DIC}/\text{HOBt}$ followed with the addition of glycine butyl ester is shown below.

The structure of the product expected when the given derivative of proline would react with $\text{DIC}/\text{HOBt}$ followed with the addition of glycine butyl ester is below.

Explanation of Solution

The valine has an amine group. This group can be protected by the reaction of valine with aqueous Fmoc-$\text{NHS}$ ester, ${\text{Na}}_{\text{2}}{\text{CO}}_{\text{3}}$ and aqueous $1,2-\text{dimethoxyethane}$ by neutralizing with ${\text{H}}_{\text{3}}{\text{O}}^{+}$. The carboxylic group of the derivative of valine can be protected with the help of reagent with $\text{DIC}/\text{HOBt}$ followed with the addition of glycine butyl ester. The corresponding chemical reaction is shown below.

Figure 13

The carboxylic group of the derivative of proline can be protected with the help of reagent with $\text{DIC}/\text{HOBt}$ followed with the addition of glycine butyl ester. The corresponding chemical reaction is shown below.

Figure 14

Conclusion

The structure of the product expected when the given derivative of valine would react with $\text{DIC}/\text{HOBt}$ followed with the addition of glycine butyl ester is shown in Figure 13.

The structure of the product expected when the given derivative of proline would react with $\text{DIC}/\text{HOBt}$ followed with the addition of glycine butyl ester is shown in Figure 14.

Interpretation Introduction

(h)

Interpretation:

The structure of the product expected when the given derivative of valine would react with anhydrous ${\text{CF}}_{\text{3}}{\text{CO}}_{\text{2}}\text{H}$ is to be predicted. The structure of the product expected when the given derivative of proline would react with anhydrous ${\text{CF}}_{\text{3}}{\text{CO}}_{\text{2}}\text{H}$ is to be predicted.

Concept introduction:

The chemical compounds in which carbon is bonded with the acidic and basic group along with hydrocarbon side chain are known as amino acids. These functional groups can be protected by different reagent to synthesize peptide chains. The protecting groups can be removed by hydrolysis.

Answer to Problem 27.43AP

The structure of the product expected when the given derivative of valine would react with anhydrous ${\text{CF}}_{\text{3}}{\text{CO}}_{\text{2}}\text{H}$ is shown below.

The structure of the product expected when the given derivative of proline would react with anhydrous ${\text{CF}}_{\text{3}}{\text{CO}}_{\text{2}}\text{H}$ is shown below.

Explanation of Solution

The derivative of valine has an ester linkage in it. The acid, ${\text{CF}}_{\text{3}}{\text{CO}}_{\text{2}}\text{H}$, can be used to hydrolysis the ester linkage of the derivative of valine. The corresponding chemical reaction is shown below.

Figure 15

The derivative of proline has an ester linkage in it. The acid, ${\text{CF}}_{\text{3}}{\text{CO}}_{\text{2}}\text{H}$, can be used to hydrolysis the ester linkage of the derivative of proline. The corresponding chemical reaction is shown below. The corresponding chemical reaction is shown below.

Figure 16

Conclusion

The structure of the product expected when the given derivative of valine would react with anhydrous ${\text{CF}}_{\text{3}}{\text{CO}}_{\text{2}}\text{H}$ is shown in Figure 15.

The structure of the product expected when the given derivative of proline would react with anhydrous ${\text{CF}}_{\text{3}}{\text{CO}}_{\text{2}}\text{H}$ is shown in Figure 16.

Interpretation Introduction

(i)

Interpretation:

The structure of the product expected when the given derivative of valine would react with $20\%$ piperidine in $\text{DMF}$ is to be predicted. The structure of the product expected when the given derivative of proline would react with $20\%$ piperidine in $\text{DMF}$ is to be predicted.

Concept introduction:

The chemical compounds in which carbon is bonded with the acidic and basic group along with hydrocarbon side chain are known as amino acids. These functional groups can be protected by different reagent to synthesize peptide chains. The protecting groups can be removed by hydrolysis.

Answer to Problem 27.43AP

The structure of the product expected when the given derivative of valine would react with $20\%$ piperidine in $\text{DMF}$ is shown below.

The structure of the product expected when the given derivative of proline would react with $20\%$ piperidine in $\text{DMF}$ is shown below.

Explanation of Solution

The solution of $20\%$ piperidine in $\text{DMF}$ is used to remove the protection of the amine group of derivative of valine. The corresponding chemical reaction is shown below.

Figure 17

The solution of $20\%$ piperidine in $\text{DMF}$ is used to remove the protection of the amine group of derivative of proline. The corresponding chemical reaction is shown below.

Figure 18

Conclusion

The structure of the product expected when the given derivative of valine would react with $20\%$ piperidine in $\text{DMF}$ is shown in Figure 17.

The structure of the product expected when the given derivative of proline would react with $20\%$ piperidine in $\text{DMF}$ is shown in Figure 18.

Interpretation Introduction

(j)

Interpretation:

The structure of the product expected when the given derivative of valine would react with $6M$ aqueous $\text{HCl}$ followed with supply of heat is to be predicted. The structure of the product expected when the given derivative of proline would react with $6M$ aqueous $\text{HCl}$ followed with supply of heat is to be predicted.

Concept introduction:

The chemical compounds in which carbon is bonded with the acidic and basic group along with hydrocarbon side chain are known as amino acids. These functional groups can be protected by different reagent to synthesize peptide chains. The protecting groups can be removed by hydrolysis.

Answer to Problem 27.43AP

The structure of the product expected when the given derivative of valine would react with $6M$ aqueous $\text{HCl}$ followed by heat is shown below.

The structure of the product expected when the given derivative of proline would react with $6M$ aqueous $\text{HCl}$ followed by heat is shown below.

Explanation of Solution

The derivative of valine has amide linkage in it. This amide linkage can be hydrolysis by heating with a strong acid such as $6M$ aqueous $\text{HCl}$. The corresponding chemical reaction is shown below.

Figure 19

The derivative of valine has amide linkage in it. This amide linkage can be hydrolysis by heating with a strong acid such as $6M$ aqueous $\text{HCl}$. The corresponding chemical reaction is shown below.

Figure 20

Conclusion

The structure of the product expected when the given derivative of valine would react with $6M$ aqueous $\text{HCl}$ followed with supply of heat is shown in Figure 19.

The structure of the product expected when the given derivative of proline would react with $6M$ aqueous $\text{HCl}$ followed with supply of heat is shown in Figure 20.