22. Carboxylic Acid Derivatives: NAS

In the mechanism for the acid-catalyzed hydrolysis of an ester,

c. what species is HB⁺ most likely to be in the hydrolysis reaction?

d. what species is HB⁺ most likely to be in the reverse reaction?

What products are formed from the acid-catalyzed hydrolysis of the following esters?

a.

b.

Because bromocyclohexane is a secondary alkyl halide, both cyclohexanol and cyclohexene are formed when the alkyl halide reacts with hydroxide ion. Suggest a method to synthesize cyclohexanol from bromocyclohexane that forms little or no cyclohexene.

(b) Finish the solution for Solved Problem 20-1 by providing a mechanism for the acid-catalyzed hydrolysis of ethyl formate.

Propose a mechanism for the acid-catalyzed hydrolysis of phenylalanine ethyl ester.

Show the mechanism for the acid-catalyzed formation of 23c starting with the product obtained from its hydrolysis.

For each heterocyclic compound,

(ii) show what compounds would result from complete hydrolysis.

(a)

(b)

(c)

The mechanism for acidic hydrolysis of a nitrile resembles the basic hydrolysis, except that the nitrile is first protonated, activating it toward attack by a weak nucleophile (water). Under acidic conditions, the proton transfer (tautomerism) involves protonation on nitrogen followed by deprotonation on oxygen. Propose a mechanism for the acid-catalyzed hydrolysis of benzonitrile to benzamide.

How could you convert N-methylbenzamide to the following compounds?

d. benzyl alcohol

How would you make the following compounds from N-benzylbenzamide?

b. benzoic acid

Show how the following compounds could be prepared from the given starting materials. You can use any necessary organic or inorganic reagents.

d.

Predict the products and propose mechanisms for the following reactions.

(a)

Aspartame, the sweetener used in the commercial products NutraSweet and Equal, is 200 times sweeter than sucrose. What products will be obtained if aspartame is hydrolyzed completely in an aqueous solution of HCl?

Compare each of the mechanisms listed here with the mechanism for each of the two parts of the acid-catalyzed hydrolysis of an ester, indicating a. similarities. b. differences.

4. acid-catalyzed hydrolysis of an amide

Propose mechanisms for the following reactions.

(c)