25. Condensation Chemistry

In condensation reactions, which of the following best describes what typically occurs?

Which of the following transformations is an example of a condensation reaction?

Which of the following reactions lead to the formation of an amide?

What compounds are obtained from the following hydrolysis reactions?

c.

Write the mechanism for the acid-catalyzed reaction of tert-butyl acetate with methanol.

Catalytic antibodies catalyze a reaction by forcing the conformation of the substrate in the direction of the transition state. The synthesis of the antibody is carried out in the presence of a transition state analog—a stable molecule that structurally resembles the transition state. This causes an antibody to be generated that recognizes and binds to the transition state, thereby stabilizing it. For example, the following transition state analog has been used to ­generate a catalytic antibody that catalyzes the hydrolysis of the structurally similar ester:

a. Draw a possible transition state for the hydrolysis reaction.

Draw the products of the following reactions:

d.

Propose a mechanism for the rearrangement of the thiazoline obtained from the reaction of Edman's reagent with a peptide to a PTH-amino acid. (Hint: Thioesters are very reactive toward nucleophiles.)

Co²⁺ catalyzes the hydrolysis of the lactam shown here. Propose a mechanism for the metal-ion catalyzed reaction.

The following compound has been found to be an inhibitor of penicillinase. The enzyme can be reactivated by hydroxylamine (NH₂OH). Propose a mechanism to account for the reactivation.

The following compound has been found to be an inhibitor of penicillinase. The enzyme can be reactivated by hydroxylamine (NH₂OH). Propose a mechanism to account for the inhibition.

A Mannich reaction puts a -group on the α-carbon of a ketone. Propose a mechanism for the reaction.