why-does-the-carbonyl-oxygen-participate-in-an-intramolecular-sn2-reaction-with-

Question

Why does the carbonyl oxygen participate in an intramolecular SN2 reaction with the gamma carbon in the methionine derivative?

Accepted Answer

To form a stable 5-membered ring structure.

Answer

To rearrange the peptide into a linear form.

Answer

To break the peptide backbone.

Answer

To create a disulfide bridge.