Chem 242 @ Dickinson

The End of Carboxylic Acids

Today was the end of Chapter 20. We talked about how to prepare carboxylic acids and noted two important new methods -- hydrolysis (reaction with water) of nitriles and reaction of Grignards with carbon dioxide. Being able to work through the mechanism of acid hydrolysis of a nitrile is a useful skill; we spent the last 12 - 15 minutes of class working on it in groups.

We also saw two examples of the astounding reactivity of lithium aluminum hydride -- when it reacts with a carboxylic acid to form an alcohol and when it reacts with a nitrile to form an amine. In both cases the hydride source continues to attack even though there is a negative charge!

At the beginning of class, I talked a bit about the modeling projects and gave a brief overview of the kinds of things that you will have to do. By the beginning of next week each student will receive an e-mail (to their Dickinson address) containing an attached file. That file will be the starting material for a Claisen rearrangement that will be studied. The instructions will be posted shortly. I mentioned that lab time would be a good time to work on these.

Chapter 21 will be the topic for the next three days. Planned coverage is Friday: 21.1 - 3; Monday: 21.4 - 5; Wednesday: 21.6 - 8. Problem set 6 and the Chapter 21 Need to Know will be posted to the right and on the web site.

posted by DCChem @ 9:35 AM