Rules of the Day 3-02-07

Click here for today's lecture mechanism sheet 1

Click here for today's lecture mechanism sheet 2

1. The characteristic reaction mechanism of carboxylic acid derivatives is Mechanism B, with or without a protonation.

2. The key issue with the four main carboxylic acid derivatives is leaving group ability. The better the leaving group ability, the more reactive the carboxylic acid derivative.

3. Listed from most to least reactive with nucleophiles, the carboxylic acid derivatives are acid chlorides, acid anhydrides, esters, amides. This is a big range of activity, as acid chlorides are extremely reactive while amides are extremely unreactive.

4. All of the carboxylic acid derivatives can be hydrolyzed, acid chlorides and anhydrides react with water directly, but the solution becomes acidic as the reaction proceeds.

5. Acid chlorides and anhydrides are so reactive that they will react with alchols directly to create esters. The mechansims are the same as for the hydrolysis reaction.

6. Esters require acid catalysis or base promotion to hydrolyze. The acid catalyzed ester hydrolysis mechanism is the functional reverse of the Fischer esterification mechanism, illustrating the concept of microscopic reversibility.

Homework: Continue Working on Homework Problem Set 6. It will be due before class next Wednesday, March 1. Reading: Sections 18.5-18.6 (If you did not already read this) Problems in Book: 18.6, 18.7, 18.21, 18.22 You will not turn these in but they are very helpful to PREPARE for the next lecture.