Whether the ortho-carboxy substituent acts as an intramolecular general-base catalyst or as an intramolecular nucleophilic catalyst can be determined by carrying out the hydrolysis of aspirin with 18O-labeled water and determining whether 18O is incorporated into ortho-carboxy-substituted phenol. Explain the results that would be obtained with the two types of catalysis.

Whether the ortho-carboxy substituent acts as an intramolecular general-base catalyst or as an intramolecular nucleophilic catalyst can be determined by carrying out the hydrolysis of aspirin with 18O-labeled water and determining whether 18O is incorporated into ortho-carboxy-substituted phenol. Explain the results that would be obtained with the two types of catalysis.

Organic Chemistry

8th Edition

ISBN:9781305580350

Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. Foote

Publisher:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. Foote

Chapter19: Enolate Anions And Enamines

Section: Chapter Questions

Problem 19.63P

See similar textbooks

Similar questions

A racemic mixture of 2-methyl-1-phenyl-1-butanone is formed when (R)-2-methyl-1-phenyl-1-butanone is dissolved in an acidic or basic aqueoussolution. Give an example of another ketone that undergoes acid- or base-catalyzed racemization.
(17, 18, 5) Give the relative rates of reaction of the four carboxylic acid derivatives below with aqueous sodium hydroxide to give the sodium carboxylate salt.
The base-promoted rearrangement of an -haloketone to a carboxylic acid, known as the Favorskii rearrangement, is illustrated by the conversion of 2-chlorocyclohexanone to cyclopentanecarboxylic acid. It is proposed that NaOH first converts the a-haloketone to the substituted cyclopropanone shown in brackets and then to the sodium salt of cyclopentanecarboxylic acid. (a) Propose a mechanism for base-promoted conversion of 2-chlorocyclohexanone to the proposed intermediate. (b) Propose a mechanism for base-promoted conversion of the proposed intermediate to sodium cyclopentanecarboxylate.
-Hydroxyketones and -hydroxyaldehydes are also oxidized by treatment with periodic acid. It is not the -hydroxyketone or aldehyde, however, that undergoes reaction with periodic acid, but the hydrate formed by addition of water to the carbonyl group of the -hydroxyketone or aldehyde. Write a mechanism for the oxidation of this -hydroxyaldehyde by HIO4.
In the acid-catalyzed dehydration of 2-methyl-1-propanol, what carbocation would be formed if a hydride shift accompanied cleavage of the carbon–oxygen bond in the alkyloxonium ion? What ion would be formed as a result of a methyl shift? Which pathway do you think will predominate, a hydride shift or a methyl shift?
Each of the following reactions has been carried out under conditions such that disubstitution or trisubstitution occurred. Identify the principal organic product in each case. (a) Nitration of p-chlorobenzoic acid (dinitration) (b) Bromination of aniline (tribromination) (c) Bromination of o-aminoacetophenone (dibromination) (d) Bromination of p-nitrophenol (dibromination) (e) Reaction of biphenyl with tert-butyl chloride and iron(III) chloride (dialkylation) (f) Sulfonation of phenol (disulfonation)
In the Grignard Reaction experiment what would the reaction mechanism be if the reactants are Magnesium, 2-bromopropane, 4-benzaldehyde, phosphoric acid and diethyl ether, resulting in a product of 1-(4-methoxyphenyl)-2-methylpropan-1-ol
Explain how benzaldehyde and dimedone reacts with each other, and then with the aminotriazole to form compound 1a in the presence of an acid catalyst. Provide a detailed reaction mechanism. During the development of the optimized procedure for the experiment, it was found out that compound 1b can also be produced from the same set of starting materials. Propose a detailed reaction mechanism for the formation of 1b. Explain your answer. What factor/s may drive the formation of 1b over 1a?
Treatment of pentanedioic (glutaric) anhydride with ammonia at elevated temperature leads to a compound of molecular formula C5H7NO2. What is the structure of this product? [Hint: You need to think about the reactivity not only of acid anhydrides but also of amides and carboxylic acids]
To synthesize trans-cinnamic acid from benzaldehyde (PhCHO) and acetic anhydride (Ac2O) under basic, refluxing conditions to exemplify the Perkin condensation. 1. Draw the complete chemical reaction to be carried out. 2. Provide a complete arrow-pushing mechanism for the synthesis of trans-cinnamic acid. 3. Briefly describe the role of water, Na2CO3, and HCl in the isolation of the product. Draw the structure of the product at basic pH (after Na2CO3 addition) and at acidic pH (after HCl addition).
(a) Arrange the following compounds in an increasing order of their indicated property :(i) Benzoic acid, 4-Nitrobenzoic acid, 3,4-Dinitrobenzoic acid, 4-Methoxybenzoic acid (acid strength)(ii) CH3CH2CH (Br) COOH, CH3CH (Br) CH2COOH,(CH3)2CHCOOH, CH3CH2CH2COOH (acid strength)(b) How would you bring about the following conversions :(i) Propanone to Propene (ii) Benzoic acid to Benzaldehyde(iii) Bromobenzene to 1-phenylethanol
Propose a mechanism for the reaction of aniline with ethyl acetate to give acetanilide.What is the leaving group in your proposed mechanism? Would this be a suitableleaving group for an SN2 reaction?