Chapter 19, Problem 19.41AP

Interpretation Introduction

(a)

Interpretation:

The product formed in the reaction of butyraldehyde and $\text{PhMgBr}$, then with dilute ${\text{H}}_3{\text{O}}^{+}$ is to be predicted.

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. The Grignard reagent is used to increase the chain length of the carbon-carbon bond.

Answer to Problem 19.41AP

The product formed in the reaction of butyraldehyde and $\text{PhMgBr}$, then with dilute ${\text{H}}_3{\text{O}}^{+}$ is an alcohol as shown below.

Explanation of Solution

Butyraldehyde reacts with $\text{PhMgBr}$, then with dilute ${\text{H}}_3{\text{O}}^{+}$ to give $\text{1-phenylbutan-1-ol}$. The product formed in this reaction is by the help of Grignard reagent.

The reduction of butyraldehyde takes place to form the product. The reaction is shown below.

Figure 1

Conclusion

The product formed in the reaction of butyraldehyde and $\text{PhMgBr}$, then with dilute ${\text{H}}_3{\text{O}}^{+}$ is $\text{1-phenylbutan-1-ol}$ as shown in Figure 1.

Interpretation Introduction

(b)

Interpretation:

The product formed in the reaction of butyraldehyde and ${\text{LiAlH}}_{\text{4}}$ in ether, then with dilute ${\text{H}}_3{\text{O}}^{+}$ is to be predicted.

Concept introduction:

The gain of electrons involved in the particular reaction is termed as reduction. The reduction process also involves the removal of an electronegative atom from a molecule followed by the hydrogen atom addition into that molecule.

Answer to Problem 19.41AP

The product formed in the reaction of butyraldehyde and ${\text{LiAlH}}_{\text{4}}$ in ether, then with dilute ${\text{H}}_3{\text{O}}^{+}$ is an alcohol as shown below.

Explanation of Solution

Butyraldehyde reacts with ${\text{LiAlH}}_{\text{4}}$, then with dilute ${\text{H}}_3{\text{O}}^{+}$ to give $\text{butan-1-ol}$. The product formed in this reaction is by the help of lithium aluminium hydride.

The reduction of butyraldehyde takes place to form the product. The reaction is shown below.

Figure 2

Conclusion

The product formed in the reaction of butyraldehyde and ${\text{LiAlH}}_{\text{4}}$, then with dilute ${\text{H}}_3{\text{O}}^{+}$ is $\text{butan-1-ol}$ as shown in Figure 2.

Interpretation Introduction

(c)

Interpretation:

The product formed in the reaction of butyraldehyde and alkaline ${\text{KMnO}}_{\text{4}}$, then with dilute ${\text{H}}_3{\text{O}}^{+}$ is to be predicted.

Concept introduction:

Oxidation is the process of addition of oxygen. Oxidation is also defined as loss of electrons. In the oxidation process, there is increase in the oxidation state. The acid is added in the reaction for protonation.

The oxidizing agent is defined as the species which oxidizes others and itself gets reduced.

Answer to Problem 19.41AP

The product formed in the reaction of butyraldehyde and ${\text{KMnO}}_{\text{4}}$, then with dilute ${\text{H}}_3{\text{O}}^{+}$ is a butyric acid as shown below.

Explanation of Solution

Butyraldehyde reacts with ${\text{KMnO}}_{\text{4}}$, then with dilute ${\text{H}}_3{\text{O}}^{+}$ to give butyric acid. The alkaline ${\text{KMnO}}_{\text{4}}$ is used to oxidize aldehyde into their respective acid. The hydronium ion is used for protonation in the reaction which is shown below.

Figure 3

Conclusion

The product formed in the reaction of butyraldehyde and alkaline ${\text{KMnO}}_{\text{4}}$, then with dilute ${\text{H}}_3{\text{O}}^{+}$ is butyric acid as shown in Figure 3.

Interpretation Introduction

(d)

Interpretation:

The product formed in the reaction of butyraldehyde and aqueous ${\text{H}}_{\text{2}}{\text{Cr}}_{\text{2}}{\text{O}}_{\text{7}}$ is to be predicted.

Concept introduction:

Oxidation is the process of addition of oxygen. Oxidation is also defined as loss of electrons. In the oxidation process, there is increase in the oxidation state. The acid is added in the reaction for protonation.

The oxidizing agent is defined as the species which oxidizes others and itself gets reduced.

Answer to Problem 19.41AP

The product formed in the reaction of butyraldehyde and aqueous ${\text{H}}_{\text{2}}{\text{Cr}}_{\text{2}}{\text{O}}_{\text{7}}$ is a butyric acid as shown below.

Explanation of Solution

Butyraldehyde reacts with aqueous ${\text{H}}_{\text{2}}{\text{Cr}}_{\text{2}}{\text{O}}_{\text{7}}$ to give butyric acid.. The aqueous ${\text{H}}_{\text{2}}{\text{Cr}}_{\text{2}}{\text{O}}_{\text{7}}$ is used to oxidize aldehyde into their respective acid. The hydronium ion is used for protonation in the reaction which is shown below.

Figure 4

Conclusion

The product formed in the reaction of butyraldehyde and aqueous ${\text{H}}_{\text{2}}{\text{Cr}}_{\text{2}}{\text{O}}_{\text{7}}$ is butyric acid as shown in Figure 4.

Interpretation Introduction

(e)

Interpretation:

The product formed in the reaction of butyraldehyde and ${\text{NH}}_{\text{2}}\text{OH}$ at $\text{pH}=\text{5}$ is to be predicted.

Concept introduction:

Oxime belongs to the family of imines. The formula of oxime is $\text{RR'C=NOH}$. Types of oxime are ketoxime and aldoxime. This reaction proceeds through a nucleophilic addition reaction. The catalyst acts as a nucleophile in the reaction.

Answer to Problem 19.41AP

The product formed in the reaction of butyraldehyde and ${\text{NH}}_{\text{2}}\text{OH}$ at $\text{pH}=\text{5}$ is a butyraldehyde oxime as shown below.

Explanation of Solution

Butyraldehyde reacts with ${\text{NH}}_{\text{2}}\text{OH}$ at $\text{pH}=\text{5}$ to give butyraldehyde oxime. The ${\text{NH}}_{\text{2}}\text{OH}$ is used to convert aldehyde into aldehyde oxime. This reaction is based on the importance of . When the is high then the product formed is an amine. However, when the is low then the product is not formed. The reaction is shown below.

Figure 5

Conclusion

The product formed in the reaction of butyraldehyde and ${\text{NH}}_{\text{2}}\text{OH}$ at $\text{pH}=\text{5}$ is butyraldehyde oxime as shown in Figure 5.

Interpretation Introduction

(f)

Interpretation:

The product formed in the reaction of butyraldehyde and ${\text{Ag}}_{\text{2}}\text{O}$ is to be predicted.

Concept introduction:

Oxidation is the process of addition of oxygen. Oxidation is also defined as loss of electrons. In the oxidation process, there is increase in the oxidation state. The acid is added in the reaction for protonation.

The oxidizing agent is defined as the species which oxidizes others and itself gets reduced.

Answer to Problem 19.41AP

The product formed in the reaction of butyraldehyde and ${\text{Ag}}_{\text{2}}\text{O}$ is a butyric acid as shown below.

Explanation of Solution

Butyraldehyde reacts with ${\text{Ag}}_{\text{2}}\text{O}$ to give butyric acid. The ${\text{Ag}}_{\text{2}}\text{O}$ is used to oxidize aldehyde into their respective acid. The ${\text{OH}}^{-}$ acts as a nucleophile which attacks on the carbonyl carbon of the aldehyde.

Figure 6

Conclusion

The product formed in the reaction of butyraldehyde and ${\text{Ag}}_{\text{2}}\text{O}$ is a butyric acid as shown in Figure 6.

Interpretation Introduction

(g)

Interpretation:

The product formed in the reaction of butyraldehyde and zinc amalgam in the presence of $\text{HCl}$ is to be predicted.

Concept introduction:

Clemmensen reduction is defined as the reduction in which aldehydes or ketones are converted into alkane or hydrocarbon. The catalyst is used in this reaction is zinc amalgam in the presence of concentrated hydrochloric acid. This is one of the easy methods to convert aldehydes or ketones into hydrocarbon.

Answer to Problem 19.41AP

The product formed in the reaction of butyraldehyde and zinc amalgam in the presence of $\text{HCl}$ is butane as shown below.

Explanation of Solution

Butyraldehyde reacts with zinc amalgam in the presence of $\text{HCl}$ to give butane. Zinc is oxidized and the losing electrons are attracted by carbonyl carbon. Then protonation takes place and carbocation is formed. Carbocation taking two electrons and neutralized by acid. The overall reaction is shown below.

Figure 7

Conclusion

The product formed in the reaction of butyraldehyde and zinc amalgam in the presence of $\text{HCl}$ is butane as shown in Figure 7.

Interpretation Introduction

(h)

Interpretation:

The product formed in the reaction of butyraldehyde and ${\text{CH}}_{\text{3}}{\text{CH=PPh}}_{\text{3}}$ is to be predicted.

Concept introduction:

The Wittig reaction is the chemical reaction that involves conversion of an aldehyde or ketone into an alkene. The chemical name of Wittig reagent is triphenyl phosphonium ylide. In the Wittig reaction, aldehydes or a ketone reacts with triphenyl phosphonium ylide to generate an alkene and triphenylphosphine oxide. The Wittig reagent gives good yields of alkene even when other functional groups are present on the aldehydes or ketone. However, as the steric hindrance of the aldehydes or ketone increases, the yield of alkene decreases.

Answer to Problem 19.41AP

The geometrical isomers are formed in the reaction of butyraldehyde and ${\text{CH}}_{\text{3}}{\text{CH=PPh}}_{\text{3}}$ as shown below.

Explanation of Solution

Butyraldehyde reacts with ${\text{CH}}_{\text{3}}{\text{CH=PPh}}_{\text{3}}$ forms two geometrical isomeric units. When the butyraldehyde is treated with ylide. The conjugate base of the phosphonium ion leads to the formation of the product. The double bond of the carbonyl bond is converted into an alkene. The cis and trans geometrical isomers are obtained. The reaction is shown below.

Figure 8

Conclusion

Butyraldehyde reacts with ${\text{CH}}_{\text{3}}{\text{CH=PPh}}_{\text{3}}$ forms two geometrical isomeric units as shown in Figure 8.