Nucleophilic Acyl Substitution Practice Problems
Edman's degradation of a peptide forms thiazoline which can undergo rearrangement in dilute acid to phenylthiohydantoin (PTH) amino acid. Propose a mechanism for the rearrangement of the thiazoline shown below. (Hint: Thioesters react readily with nucleophiles.)
Suggest a four-step synthesis involving an organocuprate reagent to produce the desired product.
Determine the structure of the compounds corresponding to i-iv for each of the following reactions:
The reaction of an acyl chloride with an aqueous solution of primary or secondary amine forms an amide as the major product. Predict the product formed when acetyl chloride reacts with trimethylamine.
Acetic acid is dissolved in isotopically labeled water (H 2O18) with an acid catalyst. Draw the labeled product(s) formed.
What neutral nucleophile would you use to convert methyl propionate into N-ethylpropionamide?
Determine the identity of the major products obtained in the reaction between benzoyl chloride and each of the compounds shown below.
(ii) potassium acetate
Show how to make each of the compounds shown below using the appropriate acyl chlorides and amines as your starting materials.
Under mild conditions, which of the proposed reactions below would take place quickly?
Show how to synthesize each of the compounds below using appropriate acyl chlorides and alcohols as the starting materials.
(i) methyl propionate
(ii) phenyl 2-methylhexanoate
Propose a plausible mechanism for the base catalyzed hydrolysis of the compound shown below.
Propose a plausible mechanism for the acid-catalyzed hydrolysis of the compound shown below.
For the following compounds, identify the products that would be obtained upon complete hydrolysis:
Show how to synthesize each of the compounds shown below using alanine as your starting material. Give the structure of each product in your answer.
(i) alanine ethyl ester
(ii) (cyclohexanecarbonyl) alanine