Concept explainers
(a)
Interpretation:
It is to be indicated whether the given conversions would be energetically favorable or unfavourable. Also, it is to be given if the reaction is likely to occur readily.
Concept introduction:
Nucleophilic acyl substitution describes a class of substitution reactions involving nucleophiles and acyl compounds. An acid derivative has a leaving group, which is substituted by a nucleophile. If the leaving group is more stable than the nucleophile (weaker in terms of basicity), then the reaction is energetically favorable and occurs readily. If the nucleophile is more stable than the leaving group, then the reaction is enegetically unfavorble and does not occur readilty. This can be explained on the basis of the stability ladder below:
An acyl substitution that converts an acid derivative from a higher rung on the stability ladder to one on a lower rung of the ladder is energetically favorable. An acyl substitution that converts an acid derivative from a lower rung on the stability ladder to one on a higher rung of the ladder is energetically unfavorable.
Answer to Problem 20.5YT
The given conversion would be energetically unfavourable, and the reaction does not occur readily.
Explanation of Solution
The given reaction is
This is an example of a nucleophilic acyl substitution reaction in which an anhydride is getting converted into an acyl chloride. An acid derivative has a leaving group, which is substituted by a nucleophile. If the leaving group is more stable than the nucleophile (weaker in terms of basicity), then the reaction is energetically favorable and occurs readily. If the nucleophile is more stable than the leaving group, then the reaction is enegetically unfavorble and does not occur readilty. This can be explained on the basis of the stability ladder below:
An acyl substitution that converts an acid derivative from a higher rung on the stability ladder to the one on a lower rung of the ladder is energetically favorable. An acyl substitution that converts an acid derivative from a lower rung on the stability ladder to one on a higher rung of the ladder is energetically unfavorable.
Referring to this chart, an acid chloride is from a lower rung while an acyl chloride is from a higher rung on the stability ladder. Thus, this reaction is energetically unfavorable and so does not occur readily.
Conversion of an acid derivative from a lower rung to higher rung on the stability ladder is energetically unfavourable, and the reaction does not occur readily.
(b)
Interpretation:
It is to be indicated whether the given conversions would be energetically favorable or unfavourable. Also, it is to be given if the reaction is likely to occur readily.
Concept introduction:
Nucleophilic acyl substitution describes a class of substitution reactions involving nucleophiles and acyl compounds. An acid derivative has a leaving group, which is substituted by a nucleophile. If the leaving group is more stable than the nucleophile (weaker in terms of basicity), then the reaction is energetically favorable and occurs readily. If the nucleophile is more stable than the leaving group, then the reaction is enegetically unfavorble and does not occur readilty. This can be explained on the basis of the stability ladder below:
An acyl substitution that converts an acid derivative from a higher rung on the stability ladder to one on a lower rung of the ladder is energetically favorable. An acyl substitution that converts an acid derivative from a lower rung on the stability ladder to one on a higher rung of the ladder is energetically unfavorable.
Answer to Problem 20.5YT
The given conversion would be energetically unfavourable, and it does not occur readily.
Explanation of Solution
The given reaction is
This is an example of a nucleophilic acyl substitution reaction in which an amide is getting converted into an ester. If the leaving group is more stable than the nucleophile (weaker in terms of basicity), then the reaction is energetically favorable and occurs readily. If the nucleophile is more stable than the leaving group, then the reaction is enegetically unfavorble and does not occur readilty. This can be explained on the basis of the stability ladder below:
An acyl substitution that converts an acid derivative from a higher rung on the stability ladder to one on a lower rung of the ladder is energetically favorable. An acyl substitution that converts an acid derivative from a lower rung on the stability ladder to one on a higher rung of the ladder is energetically unfavorable.
Referring to this chart, an amide is from a lower rung while an ester is from a higher rung on the stability ladder. Thus, this reaction is energetically unfavorable and so does not occur readily.
Conversion of an acid derivative from a lower rung to higher rung on the stability ladder is energetically unfavourable, and the reaction does not occur readily.
(c)
Interpretation:
It is to be indicated whether the given conversions would be energetically favorable or unfavourable. Also, it is to be given if the reaction is likely to occur readily.
Concept introduction:
Nucleophilic acyl substitution describes a class of substitution reactions involving nucleophiles and acyl compounds. An acid derivative has a leaving group, which is substituted by a nucleophile. If the leaving group is more stable than the nucleophile (weaker in terms of basicity), then the reaction is energetically favorable and occurs readily. If the nucleophile is more stable than the leaving group, then the reaction is enegetically unfavorble and does not occur readilty. This can be explained on the basis of the stability ladder below:
An acyl substitution that converts an acid derivative from a higher rung on the stability ladder to one on a lower rung of the ladder is energetically favorable. An acyl substitution that converts an acid derivative from a lower rung on the stability ladder to one on a higher rung of the ladder is energetically unfavorable.
Answer to Problem 20.5YT
The given conversion would be energetically unfavourable, and it does not occur readily.
Explanation of Solution
The given reaction is
This is an example of nucleophilic acyl substitution reaction in which an acid chloride is getting converted into an ester. If the leaving group is more stable than the nucleophile (weaker in terms of basicity), then the reaction is energetically favorable and occurs readily. If the nucleophile is more stable than the leaving group, then the reaction is enegetically unfavorble and does not occur readilty. This can be explained on the basis of the stability ladder below:
An acyl substitution that converts an acid derivative from a higher rung on the stability ladder to one on a lower rung of the ladder is energetically favorable. An acyl substitution that converts an acid derivative from a lower rung on the stability ladder to one on a higher rung of the ladder is energetically unfavorable.
Referring to this chart, an acid chloride is from a higher rung while an ester is from a lower rung on the stability ladder. Thus, this reaction is energetically favorable and occurs readily.
Conversion of an acid derivative from a higher rung to lower rung on the stability ladder is energetically favourable, and the reaction occurs readily.
(d)
Interpretation:
It is to be indicated whether the given conversions would be energetically favorable or unfavourable. Also, it is to be given if the reaction is likely to occur readily.
Concept introduction:
Nucleophilic acyl substitution describes a class of substitution reactions involving nucleophiles and acyl compounds. An acid derivative has a leaving group, which is substituted by a nucleophile. If the leaving group is more stable than the nucleophile (weaker in terms of basicity), then the reaction is energetically favorable and occurs readily. If the nucleophile is more stable than the leaving group, then the reaction is enegetically unfavorble and does not occur readilty. This can be explained on the basis of the stability ladder below:
An acyl substitution that converts an acid derivative from a higher rung on the stability ladder to one on a lower rung of the ladder is energetically favorable. An acyl substitution that converts an acid derivative from a lower rung on the stability ladder to one on a higher rung of the ladder is energetically unfavorable.
Answer to Problem 20.5YT
The given conversion would be energetically unfavourable, and it does not occur readily.
Explanation of Solution
The given reaction is
This is an example of a nucleophilic acyl substitution reaction in which an acid anhydride is getting converted into dicarboxylic acid. If the leaving group is more stable than the nucleophile (weaker in terms of basicity), then the reaction is energetically favorable and occurs readily. If the nucleophile is more stable than the leaving group, then the reaction is enegetically unfavorble and does not occur readilty. This can be explained on the basis of the stability ladder below:
An acyl substitution that converts an acid derivative from a higher rung on the stability ladder to one on a lower rung of the ladder is energetically favorable. An acyl substitution that converts an acid derivative from a lower rung on the stability ladder to one on a higher rung of the ladder is energetically unfavorable.
Referring to this chart, an acid anhydride is from a higher rung while a carboxylic acid is from a lower rung on the stability ladder. Thus, this reaction is energetically favorable and occurs readily.
Conversion of an acid derivative from a higher rung to lower rung on the stability ladder is energetically favourable, and the reaction occurs readily.
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Chapter 20 Solutions
Organic Chemistry: Principles and Mechanisms (Second Edition)
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- Draw the structures of the missing reactants, intermediates, or products in the following mechanism. Include all lone pairs.arrow_forwardA proton transfer reaction can occur when an aldehyde is placed in strong base, such as an alkoxide ion, producing an alcohol and a charged conjugate base that is resonance stabilized. In the left box, draw the curved arrows for the proton transfer. In the middle and right boxes, draw the two structures for the resonance-stabilized product as noted in the box-specific directions. Be sure to include all lone pairs and nonzero formal charges.arrow_forwardDetermine the product for each of the following reactions and determing which product will predominate.arrow_forward
- Organic Chemistry: A Guided InquiryChemistryISBN:9780618974122Author:Andrei StraumanisPublisher:Cengage Learning