Chapter 13, Problem 13.29P

Interpretation Introduction

(a)

Interpretation:

It is to be determined whether each of the following syntheses requires a reaction that alters the carbon skeleton.

Concept introduction:

Chemical syntheses are carries out by transforming one functional group to another. If the bonding arrangement of carbon atoms remains the same in the product formed, that means the synthesis does not require a change in the carbon skeleton. If it is changed, that means the synthesis requires a change in the carbon skeleton. The forming or breaking of carbon-carbon $\text{π}$ bond is not considered because the bonding arrangement of carbon atoms remains the same due to the $\text{σ}$ bond between those atoms.

Answer to Problem 13.29P

This chemical synthesis does require a reaction that alters the carbon skeleton because a carbon-carbon $\text{σ}$ bond must break.

Explanation of Solution

The given chemical synthesis is

The starting compound is a six carbons ring whereas the product is a seven membered ring with one oxygen atom. Thus, the arrangement of carbon atoms in the product has changed by breaking the carbon-carbon $\text{σ}$ bond.

Therefore, this transformation requires a reaction that alters the carbon skeleton.

Conclusion

It is determined that the synthesis requires a reaction that alters the carbon skeleton based on the change in the arrangement of carbon atoms.

Interpretation Introduction

(b)

Interpretation:

It is to be determined whether each of the following syntheses requires a reaction that alters the carbon skeleton.

Concept introduction:

Chemical syntheses are carries out by transforming one functional group to another. If the bonding arrangement of carbon atoms remains the same in the product formed, that means the synthesis does not require a change in the carbon skeleton. If it is changed, that means the synthesis requires a change in the carbon skeleton. The forming or breaking of carbon-carbon $\text{π}$ bond is not considered because the bonding arrangement of carbon atoms remains the same due to the $\text{σ}$ bond between those atoms.

Answer to Problem 13.29P

This chemical synthesis does not require a reaction that alters the carbon skeleton as there is no need to break or form a carbon-carbon $\text{σ}$ bond.

Explanation of Solution

The given chemical synthesis is

The starting compound is an alcohol, and the product is ether. The transformation occurs by replacement of the hydrogen attached to oxygen by the isopropyl group, which requires breaking of $\text{O}-\text{H}$ bond and formation of $\text{O}-\text{C}$ bond. It does not break or form carbon-carbon $\text{σ}$ bond; thus, there is no change in the arrangement of carbon atoms from the starting compound to product. Therefore, this transformation does not require a reaction that alters the carbon skeleton.

Conclusion

It is determined that the synthesis does not require a reaction that alters the carbon skeleton based on the retention of the arrangement of carbon atoms.

Interpretation Introduction

(c)

Interpretation:

It is to be determined whether each of the following syntheses requires a reaction that alters the carbon skeleton.

Concept introduction:

Chemical syntheses are carries out by transforming one functional group to another. If the bonding arrangement of carbon atoms remains the same in the product formed, that means the synthesis does not require a change in the carbon skeleton. If it is changed, that means the synthesis requires a change in the carbon skeleton. The forming or breaking of carbon-carbon $\text{π}$ bond is not considered because the bonding arrangement of carbon atoms remains the same due to the $\text{σ}$ bond between those atoms.

Answer to Problem 13.29P

This chemical synthesis does require a reaction that alters the carbon skeleton because a carbon-carbon $\text{σ}$ bond must form.

Explanation of Solution

The given chemical synthesis is

In this chemical synthesis, the carboxylic acid is converted to a ketone by a replacement of hydroxyl group bonded to carbonyl carbon with the methyl group. This occurs by breaking of $\text{O}-\text{H}$ bond and formation of $\text{C}-\text{C}$ bond.

It means there is a formation of carbon-carbon $\text{σ}$ bond that changes the arrangement of carbon atoms. Therefore, this synthesis requires a reaction that alters the carbon skeleton.

Conclusion

It is determined that the synthesis requires a reaction that alters the carbon skeleton based on the change in the arrangement of carbon atoms.

Interpretation Introduction

(d)

Interpretation:

It is to be determined whether each of the following syntheses requires a reaction that alters the carbon skeleton.

Concept introduction:

Chemical syntheses are carries out by transforming one functional group to another. If the bonding arrangement of carbon atoms remains the same in the product formed, that means the synthesis does not require a change in the carbon skeleton. If it is changed, that means the synthesis requires a change in the carbon skeleton. The forming or breaking of carbon-carbon $\text{π}$ bond is not considered because the bonding arrangement of carbon atoms remains the same due to the $\text{σ}$ bond between those atoms.

Answer to Problem 13.29P

This chemical synthesis does not require a reaction that alters the carbon skeleton because carbon-carbon $\text{π}$ bond must break, but there is no need to break or form carbon-carbon $\text{σ}$ bond.

Explanation of Solution

The given chemical synthesis is

The starting compound is an alkene, and the product is ether. The transformation occurs by addition of ${\text{HOCH}}_{\text{2}}{\text{CH}}_{\text{3}}$ across the double bond, which requires breaking of carbon-carbon $\text{π}$ bond and formation of $\text{O}-\text{C}$ bond. It does not break or form the carbon-carbon $\text{σ}$ bond; thus, there is no change in the arrangement of carbon atoms from the starting compound to the product. Therefore, this synthesis does not require a reaction that alters the carbon skeleton.

Conclusion

It is determined that the synthesis does not require a reaction that alters the carbon skeleton based on the retention of arrangement of carbon atoms.

Interpretation Introduction

(e)

Interpretation:

It is to be determined whether each of the following syntheses requires a reaction that alters the carbon skeleton.

Concept introduction:

Chemical syntheses are carries out by transforming one functional group to another. If the bonding arrangement of carbon atoms remains the same in the product formed, that means the synthesis does not require a change in the carbon skeleton. If it is changed, that means the synthesis requires a change in the carbon skeleton. The forming or breaking of carbon-carbon $\text{π}$ bond is not considered because the bonding arrangement of carbon atoms remains the same due to the $\text{σ}$ bond between those atoms.

Answer to Problem 13.29P

This chemical synthesis does require a reaction that alters the carbon skeleton because a carbon-carbon $\text{σ}$ bond must form.

Explanation of Solution

The given chemical synthesis is

In this chemical synthesis, the hydrogen atom of benzene is replaced by the acetyl group, ${\text{CH}}_{\text{3}}\text{C=O}$, which occurs by breaking of $\text{C}-\text{H}$ bond and formation of $\text{C}-\text{C}$ bond. It means there is a formation of carbon-carbon $\text{σ}$ bond that changes the arrangement of carbon atoms.

Therefore, this synthesis requires a reaction that alters the carbon skeleton.

Conclusion

It is determined that the synthesis requires a reaction that alters the carbon skeleton based on the change in the arrangement of carbon atoms.

Interpretation Introduction

(f)

Interpretation:

It is to be determined whether each of the following syntheses requires a reaction that alters the carbon skeleton.

Concept introduction:

Chemical syntheses are carries out by transforming one functional group to another. If the bonding arrangement of carbon atoms remains the same in the product formed, that means the synthesis does not require a change in the carbon skeleton. If it is changed, that means the synthesis requires a change in the carbon skeleton. The forming or breaking of carbon-carbon $\text{π}$ bond is not considered because the bonding arrangement of carbon atoms remains the same due to the $\text{σ}$ bond between those atoms.

Answer to Problem 13.29P

This chemical synthesis does require a reaction that alters the carbon skeleton because a carbon-carbon $\text{σ}$ bond must form.

Explanation of Solution

The given chemical synthesis is

The starting compound has a five carbons ring with double bond, and the product has a five carbons ring fused with a three-membered ring. This could occur by breaking of carbon-carbon $\text{π}$ bond and forming of two carbon-carbon $\sigma$ bonds. Thus, there is change in the arrangement of carbon atoms.

Therefore, this synthesis requires a reaction that alters the carbon skeleton.

Conclusion

It is determined that the synthesis requires a reaction that alters the carbon skeleton based on the change in arrangement of carbon atoms.

Interpretation Introduction

(g)

Interpretation:

This chemical synthesis does require a reaction that alters the carbon skeleton because a carbon-carbon $\text{σ}$ bond must form.

Concept introduction:

Chemical syntheses are carries out by transforming one functional group to another. If the bonding arrangement of carbon atoms remains the same in the product formed, that means the synthesis does not require a change in the carbon skeleton. If it is changed, that means the synthesis requires a change in the carbon skeleton. The forming or breaking of carbon-carbon $\text{π}$ bond is not considered because the bonding arrangement of carbon atoms remains the same due to the $\text{σ}$ bond between those atoms.

Answer to Problem 13.29P

No, this chemical synthesis does not require a reaction that alters the carbon skeleton because carbon-carbon $\text{π}$ bond must break and two carbon-oxygen $\sigma$ bonds must form, but there is no need to break or form carbon-carbon $\text{σ}$ bond.

Explanation of Solution

The given chemical synthesis is

The starting compound is an alkene, and the product is epoxide. The transformation occurs by breaking of carbon-carbon $\text{π}$ bond and forming two carbon-oxygen $\sigma$ bonds. Thus, there is no breaking or forming of carbon-carbon $\sigma$ bond and hence no change in the arrangement of carbon atoms. Therefore, this transformation does not require a reaction that alters the carbon skeleton.

Conclusion

It is determined that the synthesis does not require a reaction that alters the carbon skeleton based on the retention of arrangement of carbon atoms.

Interpretation Introduction

(h)

Interpretation:

It is to be determined whether each of the following syntheses requires a reaction that alters the carbon skeleton.

Concept introduction:

Chemical syntheses are carries out by transforming one functional group to another. If the bonding arrangement of carbon atoms remains the same in the product formed, that means the synthesis does not require a change in the carbon skeleton. If it is changed, that means the synthesis requires a change in the carbon skeleton. The forming or breaking of carbon-carbon $\text{π}$ bond is not considered because the bonding arrangement of carbon atoms remains the same due to the $\text{σ}$ bond between those atoms.

Answer to Problem 13.29P

This chemical synthesis does require a reaction that alters the carbon skeleton because a carbon-carbon $\text{σ}$ bond must form.

Explanation of Solution

The given chemical synthesis is

The starting compound has a five carbons chain with two conjugated double bonds, and the product has a six carbons ring fused. This could occur by breaking of carbon-carbon $\text{π}$ bond and forming at least two carbon-carbon $\sigma$ bonds. Thus, there is change in the arrangement of carbon atoms.

Therefore, this synthesis requires a reaction that alters the carbon skeleton.

Conclusion

It is determined whether the synthesis requires a reaction that alters the carbon skeleton based on the change in the arrangement of carbon atoms.