Chapter 24, Problem 24.9P

Interpretation Introduction

(a)

Interpretation: The aldol product that is formed by the reaction of the two molecules of butanal in the presence of base is to be shown. The reagents that are needed to convert the obtained product to the given compound are to be predicted.

Concept introduction: Aldol reaction is the condensation reaction of the organic chemistry. In this reaction an enolate ion or an enol reacts with the 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 24.9P

The aldol product that is formed by the reaction of the two molecules of butanal in the presence of base is $2-\text{ethyl}-3-\text{hydroxyhexanal}$. The reagents that are needed to convert $2-\text{ethyl}-3-\text{hydroxyhexanal}$ to the given compound are shown below:

Explanation of Solution

The aldol product that is formed by the reaction of the two molecules of butanal in the presence of base is shown as,

Figure 1

In this reaction, first of all, one equivalent of butanal is treated with the strong base that results in the formation of a resonance-stabilized enolate ion. This enolate ion reacts with the second equivalent of butanal followed by the hydrolysis that leads to the formation of the desired product, $2-\text{ethyl}-3-\text{hydroxyhexanal}$.

The reagents that are needed to convert $2-\text{ethyl}-3-\text{hydroxyhexanal}$ to the given compound are shown as,

Figure 2

Thus, the reagent that is needed to convert $2-\text{ethyl}-3-\text{hydroxyhexanal}$ to the given compound is sodium borohydride present in the solution of methanol. In this reaction, $2-\text{ethyl}-3-\text{hydroxyhexanal}$ gets reduced by sodium borohydride that results in the formation of a primary alcohol as the desired product.

Conclusion

The aldol product that is formed by the reaction of the two molecules of butanal in the presence of base is $2-\text{ethyl}-3-\text{hydroxyhexanal}$. The reagents that are needed to convert $2-\text{ethyl}-3-\text{hydroxyhexanal}$ to the given compound are shown in Figure 2.

Interpretation Introduction

(b)

Interpretation: The aldol product that is formed by the reaction of the two molecules of butanal in the presence of base is to be shown. The reagents that are needed to convert the obtained product to the given compound are to be predicted.

Concept introduction: Aldol reaction is the condensation reaction of the organic chemistry. In this reaction an enolate ion or an enol reacts with the 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 24.9P

The aldol product that is formed by the reaction of the two molecules of butanal in the presence of base is $2-\text{ethyl}-3-\text{hydroxyhexanal}$. The reagents that are needed to convert $2-\text{ethyl}-3-\text{hydroxyhexanal}$ to the given compound are shown below:

Explanation of Solution

The aldol product that is formed by the reaction of the two molecules of butanal in the presence of base is shown in Figure 1.

In this reaction, first of all, one equivalent of butanal is treated with the strong base that results in the formation of a resonance-stabilized enolate ion. This enolate ion reacts with the second equivalent of butanal followed by the hydrolysis that leads to the formation of the desired product, $2-\text{ethyl}-3-\text{hydroxyhexanal}$.

The reagents that are needed to convert $2-\text{ethyl}-3-\text{hydroxyhexanal}$ to the given compound are shown as,

Figure 3

In this reaction, $2-\text{ethyl}-3-\text{hydroxyhexanal}$ undergoes dehydration in the presence of a base that leads to the formation of $2-\text{ethylhex}-2-\text{enal}$. The compound, $2-\text{ethylhex}-2-\text{enal}$ reacts with dimethyl lithium cuprate followed by the hydrolysis that results in the formation of the desired product.

Conclusion

The aldol product that is formed by the reaction of the two molecules of butanal in the presence of base is $2-\text{ethyl}-3-\text{hydroxyhexanal}$. The reagents that are needed to convert $2-\text{ethyl}-3-\text{hydroxyhexanal}$ to the given compound are shown in Figure 3.

Interpretation Introduction

(c)

Interpretation: The aldol product that is formed by the reaction of the two molecules of butanal in the presence of base is to be shown. The reagents that are needed to convert the obtained product to the given compound are to be predicted.

Concept introduction: Aldol reaction is the condensation reaction of the organic chemistry. In this reaction an enolate ion or an enol reacts with the 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 24.9P

The aldol product that is formed by the reaction of the two molecules of butanal in the presence of base is $2-\text{ethyl}-3-\text{hydroxyhexanal}$. The reagents that are needed to convert $2-\text{ethyl}-3-\text{hydroxyhexanal}$ to the given compound are shown below:

Explanation of Solution

The aldol product that is formed by the reaction of the two molecules of butanal in the presence of base is shown in Figure 1.

In this reaction, first of all, one equivalent of butanal is treated with the strong base that results in the formation of a resonance-stabilized enolate ion. This enolate ion reacts with the second equivalent of butanal followed by the hydrolysis that leads to the formation of the desired product, $2-\text{ethyl}-3-\text{hydroxyhexanal}$.

The reagents that are needed to convert $2-\text{ethyl}-3-\text{hydroxyhexanal}$ to the given compound are shown as,

Figure 4

In this reaction, $2-\text{ethyl}-3-\text{hydroxyhexanal}$ undergoes dehydration in the presence of a base that leads to the formation of $2-\text{ethylhex}-2-\text{enal}$. The compound, $2-\text{ethylhex}-2-\text{enal}$ reacts with sodium borohydride followed by the hydrolysis that results in the formation of the desired product.

Conclusion

The aldol product that is formed by the reaction of the two molecules of butanal in the presence of base is $2-\text{ethyl}-3-\text{hydroxyhexanal}$. The reagents that are needed to convert $2-\text{ethyl}-3-\text{hydroxyhexanal}$ to the given compound are shown in Figure 4.

Interpretation Introduction

(d)

Interpretation: The aldol product that is formed by the reaction of the two molecules of butanal in the presence of base is to be shown. The reagents that are needed to convert the obtained product to the given compound are to be predicted.

Concept introduction: Aldol reaction is the condensation reaction of the organic chemistry. In this reaction an enolate ion or an enol reacts with the 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 24.9P

The aldol product that is formed by the reaction of the two molecules of butanal in the presence of base is $2-\text{ethyl}-3-\text{hydroxyhexanal}$. The reagents that are needed to convert $2-\text{ethyl}-3-\text{hydroxyhexanal}$ to the given compound are shown below:

Explanation of Solution

The aldol product that is formed by the reaction of the two molecules of butanal in the presence of base is shown in Figure 1.

In this reaction, first of all, one equivalent of butanal is treated with the strong base that results in the formation of a resonance-stabilized enolate ion. This enolate ion reacts with the second equivalent of butanal followed by the hydrolysis that leads to the formation of the desired product, $2-\text{ethyl}-3-\text{hydroxyhexanal}$.

The reagents that are needed to convert $2-\text{ethyl}-3-\text{hydroxyhexanal}$ to the given compound are shown as,

Figure 5

In this reaction, $2-\text{ethyl}-3-\text{hydroxyhexanal}$ undergoes dehydration in the presence of a base that leads to the formation of $2-\text{ethylhex}-2-\text{enal}$. The compound, $2-\text{ethylhex}-2-\text{enal}$ reacts with methylmagnesium bromide followed by the hydrolysis that results in the formation of the desired product.

Conclusion

The aldol product that is formed by the reaction of the two molecules of butanal in the presence of base is $2-\text{ethyl}-3-\text{hydroxyhexanal}$. The reagents that are needed to convert $2-\text{ethyl}-3-\text{hydroxyhexanal}$ to the given compound are shown in Figure 5.