Chapter 22, Problem 22.22P

Interpretation Introduction

(a)

Interpretation:

Whether the given compound is synthesized in good yield or not by an aldol condensation with its starting materials is to be stated. The reason as to why the required aldol condensation would not succeed for compound that is not synthesized in good yield is to be stated.

Concept Introduction:

Aldol condensation is the nucleophilic addition reaction of the carbonyl compounds. An enolate ion generated from one of the carbonyl compound attack the electrophilic carbon of the other carbonyl compound to produce $\beta$-hydroxy aldol or $\beta$-hydroxy ketone. This product further gives dehydration or condensation product by elimination small molecule such as water.

Answer to Problem 22.22P

The given compound can be synthesized using aldol condensation in good yield. The starting materials are $p-\text{methoxybenzaldehyde}$ and $\text{pentan}-3-\text{one}$.

Explanation of Solution

The given compound is shown below.

Figure 1

In the above preparation of the compound, the enolate is generated on the $\alpha -$ carbon of the $\text{pentan}-3-\text{one}$ which is favorable to be generated on ketone rather than aldehyde. The enolate is then attack on the electrophilic carbon of the $p-\text{methoxybenzaldehyde}$ to produce $\beta -\text{hydroxyketone}$ which is finally dehydrated to give the condensed product. Therefore, the given compound is synthesized using aldol condensation in good yield. The structures of the starting materials which are used to produce the given compound are shown below.

Figure 2

Conclusion

The given compound can be synthesized by aldol condensation of $p-\text{methoxybenzaldehyde}$ and $\text{pentan}-3-\text{one}$.

Interpretation Introduction

(b)

Interpretation:

Whether the given compound is synthesized in good yield or not by an aldol condensation with its starting materials is to be stated. The reason as to why the required aldol condensation would not succeed for compound that is not synthesized in good yield is to be stated.

Concept Introduction:

Aldol condensation is the nucleophilic addition reaction of the carbonyl compounds. An enolate ion generated from one of the carbonyl compound attack the electrophilic carbon of the other carbonyl compound to produce $\beta$-hydroxy aldol or $\beta$-hydroxy ketone. This product further gives dehydration or condensation product by elimination small molecule such as water.

Answer to Problem 22.22P

The given compound can be synthesized using aldol condensation in good yield. The starting materials are benzaldehyde and $\text{hexan}-3-\text{one}$.

Explanation of Solution

The given compound is shown below.

Figure 3

In the preparation of the above compound, the enolate will be generated on the $\alpha -$ carbon of $\text{hexan}-3-\text{one}$ which is favorable to be generated on ketone rather than aldehyde. The enolate will then attack the electrophilic carbon of the benzaldehyde to produce the $\beta -\text{hydroxyketone}$ which is finally dehydrated to give the condensed product.

The structures of the starting materials which are used to produce the given compound are shown below.

Figure 4

Conclusion

The given compound can be synthesized by aldol condensation of benzaldehyde and $\text{hexan}-3-\text{one}$.

Interpretation Introduction

(c)

Interpretation:

Whether the given compound is synthesized in good yield or not by an aldol condensation with its starting materials is to be stated. The reason as to why the required aldol condensation would not succeed for compound that is not synthesized in good yield is to be stated.

Concept Introduction:

Aldol condensation is the nucleophilic addition reaction of the carbonyl compounds. An enolate ion generated from one of the carbonyl compound attack the electrophilic carbon of the other carbonyl compound to produce $\beta$-hydroxy aldol or $\beta$-hydroxy ketone. This product further gives dehydration or condensation product by elimination small molecule such as water.

Answer to Problem 22.22P

The given compound can be synthesized using aldol condensation but not in a good in good yield. The starting material is $\text{7}-\text{oxoctanal}$.

Explanation of Solution

The given compound is shown below.

Figure 5

In the preparation of the above compound, intramolecular aldol condensation takes place. To form this compound enolate must be generated by aldehyde and it has to attack the carbonyl carbon of ketone which is not favorable condition. Favorable condition is that enolate should be generated on ketone which attacks the electrophilic carbon of the aldehyde. This is because the carbon of aldehyde is more acidic than the carbon of ketone. The structure of the starting material which is used to produce the given compound is shown below.

Figure 6

Therefore, the given compound cannot be synthesized by aldol condensation in a good yield.

Conclusion

This compound cannot be synthesized in a good yield by the aldol condensation.

Interpretation Introduction

(d)

Interpretation:

Whether the given compound is synthesized in good yield or not by an aldol condensation with its starting materials is to be stated. The reason as to why the required aldol condensation would not succeed for compound that is not synthesized in good yield is to be stated.

Concept Introduction:

Aldol condensation is the nucleophilic addition reaction of the carbonyl compounds. An enolate ion generated from one of the carbonyl compound attack the electrophilic carbon of the other carbonyl compound to produce $\beta$-hydroxy aldol or $\beta$-hydroxy ketone. This product further gives dehydration or condensation product by elimination small molecule such as water.

Answer to Problem 22.22P

The given compound can be synthesized by aldol condensation in good yield. The starting material is $6-\text{oxoheptanal}$.

Explanation of Solution

The given compound is shown below.

Figure 7

The given compound, is prepared by the intramolecular aldol condensation of $6-\text{oxoheptanal}$ to produce the $\beta -\text{hydroxyketone}$ which is finally dehydrated to give the condensed product. This compound is prepared in a good yield because of the presence of the three acidic carbon atoms which results in the formation of carbanion at three different places. The structure of the starting material which is used to produce the given compound is shown below.

Figure 8

Conclusion

The given compound can be synthesized by intramolecular aldol condensation of $6-\text{oxoheptanal}$ in a good yield.

Interpretation Introduction

(e)

Interpretation:

Whether the given compound is synthesized in good yield or not by an aldol condensation with its starting materials is to be stated. The reason as to why the required aldol condensation would not succeed for compound that is not synthesized in good yield is to be stated.

Concept Introduction:

Aldol condensation is the nucleophilic addition reaction of the carbonyl compounds. An enolate ion generated from one of the carbonyl compound attack the electrophilic carbon of the other carbonyl compound to produce $\beta$-hydroxy aldol or $\beta$-hydroxy ketone. This product further gives dehydration or condensation product by elimination small molecule such as water.

Answer to Problem 22.22P

The given compound can be synthesized from aldol condensation in a good yield. The starting materials are: $1,3-\text{diphenylpropan}-2-\text{one}$ and benzil.

Explanation of Solution

The given compound is shown below.

Figure 9

In the preparation of the given compound, the enolate will be generated on the $\alpha$-carbon of the ketone group of $1,3-\text{diphenylpropan}-2-\text{one}$ which is the only possibility of generation of enolate in the $1,3-\text{diphenylpropan}-2-\text{one}$. The enolate will then attack the electrophilic carbon of the ketone group of the benzil to produce $\beta -\text{hydroxyketone}$ which is finally dehydrated to give the condensed product. The structures of the starting materials are shown below.

Figure 10

Conclusion

The given compound can be synthesized by aldol condensation of $1,3-\text{diphenylpropan}-2-\text{one}$ and benzyl in a good yield.

Interpretation Introduction

(f)

Interpretation:

Whether the given compound is synthesized in good yield or not by an aldol condensation with its starting materials is to be stated. The reason as to why the required aldol condensation would not succeed for compound that is not synthesized in good yield is to be stated.

Concept Introduction:

Aldol condensation is the nucleophilic addition reaction of the carbonyl compounds. An enolate ion generated from one of the carbonyl compound attack the electrophilic carbon of the other carbonyl compound to produce $\beta$-hydroxy aldol or $\beta$-hydroxy ketone. This product further gives dehydration or condensation product by elimination small molecule such as water.

Answer to Problem 22.22P

The given compound can be synthesized by aldol condensation in a good yield. The starting materials are $2\text{ moles}$ of benzaldehyde and acetone.

Explanation of Solution

The given compound is shown below.

Figure 11

In the preparation of the compound, the enolate is generated on the $\alpha$-carbon of the ketonic group of acetone which is favorable to be generated on ketone rather than aldehyde. The enolate will then attack the electrophilic carbon of the aldehyde group of the benzaldehyde to produce $\beta -\text{hydroxyketone}$ is finally dehydrated to give the condensed product. The structures of the starting materials for the preparation of the given compound are shown below.

Figure 12

Conclusion

The given compound can be synthesized by aldol condensation of benzaldehyde and acetone.

Interpretation Introduction

(g)

Interpretation:

Whether the given compound is synthesized in good yield or not by an aldol condensation with its starting materials is to be stated. The reason as to why the required aldol condensation would not succeed for compound that is not synthesized in good yield is to be stated.

Concept Introduction:

Aldol condensation is the nucleophilic addition reaction of the carbonyl compounds. An enolate ion generated from one of the carbonyl compound attack the electrophilic carbon of the other carbonyl compound to produce $\beta$-hydroxy aldol or $\beta$-hydroxy ketone. This product further gives dehydration or condensation product by elimination small molecule such as water.

Answer to Problem 22.22P

The given compound can be synthesized by aldol condensation. The starting materials are trimethylacetone and acetaldehyde.

Explanation of Solution

The given compound is shown below.

Figure 13

In the preparation of the given compound, the enolate will be generated on the $\alpha$-carbon of the ketonic group of trimethylacetone which is favorable to be generated on ketone rather than aldehyde. The enolate will then attack the electrophilic carbon of the aldehyde group of the acetaldehyde to produce $\beta -\text{hydroxyketone}$ which is finally dehydrated to give the condensed product. The structures of the starting materials, acetaldehyde and trimethylacetone are shown below.

Figure 14

Conclusion

The given compound can be synthesized by aldol condensation by trimethylacetone and acetaldehyde in a good yield.

Interpretation Introduction

(h)

Interpretation:

Whether the given compound is synthesized in good yield or not by an aldol condensation with its starting materials is to be stated. The reason as to why the required aldol condensation would not succeed for compound that is not synthesized in good yield is to be stated.

Concept Introduction:

Aldol condensation is the nucleophilic addition reaction of the carbonyl compounds. An enolate ion generated from one of the carbonyl compound attack the electrophilic carbon of the other carbonyl compound to produce $\beta$-hydroxy aldol or $\beta$-hydroxy ketone. This product further gives dehydration or condensation product by elimination small molecule such as water.

Answer to Problem 22.22P

The given compound can be synthesized by aldol condensation in a good yield. The starting material is $\text{cyclodecan}-1,6-\text{dione}$.

Explanation of Solution

The given compound is shown below.

Figure 15

The enolate will be generated on the $\alpha$-carbon of the ketonic group of $\text{cyclodecan}-1,6-\text{dione}$ which is favorable to be generated on ketone rather than aldehyde. The enolate will then attack the electrophilic carbon of the aldehyde group of the $\text{cyclodecan}-1,6-\text{dione}$ to produce $\beta -\text{hydroxyketone}$ which is finally dehydrated to give the condensed product. The structure of the starting material is shown below.

Figure 16

Conclusion

The given compound can be synthesized by aldol condensation of $\text{cyclodecan}-1,6-\text{dione}$ in a good yield.