What product would you expect to be formed in the reaction of phenylalanine with ethanol in the presence of hydrogen chloride? (Do not show the amino acid as a zwitterion, show the answer as a neutral amino acid). Ph NH CH2CH3 Edit Drawing

Another method to form a peptide bond involves a two-step process:[1] Conversion of a Boc-protected amino acid to a p-nitrophenyl ester.[2] Reaction of the p-nitrophenyl ester with an amino acid ester.a. Why does a p-nitrophenyl ester “activate” the carboxy group of the first amino acid to amide formation? b. Would a p-methoxyphenyl ester perform the same function? Why or why not?

Draw the structure of leu-enkephalin, a pentapeptide that acts as an analgesic and opiate, and has the following sequence: Tyr–Gly–Gly–Phe–Leu. (The structure of a related peptide, met-enkephalin, appeared in Section 22.6B.)

4) What would happen if you treated Alanine (above) with an aqueous solution of: a. HCI HO b. NaOH HO NH₂ NH₂ HCI NaOH

The last part is incorrect. Please provide the correct solution.

Draw a structural formula for the product formed when alanine is treated with the following reagent . Q.)(CH3CO)2O, CH3COONa

Which of the following amines can be used to resolve a racemic mixture of amino acids?

Another method to form a peptide bond involves a two-step process Reaction of the p-nitrophenyl ester with an amino acid ester. Why does a p-nitrophenyl ester “activate” the carboxy group of thefirst amino acid to amide formation?

2

13. Explain why the dansyl chloride treatment of a single polypeptide chain followed by its complete acid hydrolysis yields several dansylated amino acids.