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Rules of the Day 3-7-08

Click here for a copy of the mechanism sheet used in lecture today.

1. When learning mechanisms, the key to "catching the wave" is to always ask yourself WHY each step hapens the way it does. When you start understanding the answers to that question at each step, the whole thing will make sense.

2. Water and alcohols are such weak nucleophiles that they can only react with very reactive carbonyl species (acid chlorides or anhydrides) directly, and they require acid with all other carbonyl species (aldehydes, ketones, esters, carboxylic acids, amides).

3. Amines and anions such as hydroxide are strong enough nucleophiles that they react with all carbonyl species directly (no acid involved).

4. All the different carbonyl mechanism as variations on common themes, mechainsms A-D. Each step is one of the four elements of 1) Add a proton, 2) Take a proton away, 3) Attack with a nucleophile, 4) Loss of a leaving group.

5. A great way to study for organic or any class is to EVERY WEEK prepare "cheat sheets" for yourself that contain all of the information on them you would need to take into the next midterm ((of course the midterms are closed book, but imagine what would be on the sheets if we did allow you to bring four pieces of paper to each exam).

6. A roadmap is a "concept map" for the different reactions we have learned, allowing you to NAVIGATE synthesis problems.

7. A great way to practice for synthesis problems is to write the reactions we have learned backwards, that is, write the products of each reaction, followed by the starting materials and riagents needed to make them. In other words, focus on being able to identify Key Recognition Elements for each reaction!

 

Homework:Continue Working on Homework Problem Set 7. It will be due before class on Wednesday, March 19. Reading: Sections 19.1-19.2 Problems in Book: 18.34, 18.35, 18.37, 18.43, 18.44, 18.51, 19.1-19.3, 19.17-19.19 You will not turn these in but they are very helpful to PREPARE for the next lecture.