Topic 3: The Diels-Alder reaction, Part I: concerted [4 + 2] cycloaddition

3.1 Who were Diels and Alder? They‘re long dead, it turns out. When did they do this work? Did they know each other? Were they friends? competitors?
 
3.2 Does “Diels” rhyme with “deals” or “dials”? How do you know?
 
3.3 What exactly is the Diels-Alder reaction? Use a source beyond your book to be sure you have the best definition.
 
3.4 What is a concerted reaction? And why is that especially good for selectivity?
 
3.5 Why is the Diels-Alder reaction still one of the most powerful, most reliable, most used reactions in synthetic organic chemistry, even after all these years?
 
3.6 What is an intramolecular Diels-Alder reaction?
 
3.7 What is a hetero Diels-Alder reaction?+I292
 

Topic 4: The Diels-Alder reaction, Part II: stereo- and regio-selectivity

4.1 The Diels-Alder reaction is both stereoselective and regioselective. Explain the origins of this selectivity
 
4.1 How many different isomeric outcomes are possible in the Diels-Alder addition of the following two compounds? Find pairwise relationships among them that are enantiomeric, diastereomeric, or neither (that is, the two are regioisomers, not stereoisomers).

 
4.2 The Diels-Alder reaction, like the SN2 reaction or catalytic hydrogenation, is also stereospecific. What is it about all these mechanisms that raise them to the special level of being stereospecific, not just stereoselective?
 
4.3 How does your book define “endo” and “exo”?
 
4.4 Can you define endo addition without any reference to a “bridge” position? That is, how would you generalize the idea in the book to real cases, where the diene is not a 1,3-cyclopentadiene?
 
4.5How do the terms “electron withdrawing group” and “electron donating group” fit into this discussion?
 
4.6What is “partial charge”? And how does that fit into this conversation?
 
4.7The Diels-Alder reaction is concerted, but that does not mean all bonds are being formed to the same extent at all times. In order to explain the very high regioselectivity of the Diels-Alder reaction, which bond is probably most formed first?
 
4.8 What is an asymmetric Diels-Alder reaction? Why might that be of particular practical use?
 
16 questions
472 questions for Organic II

472 Questions for Organic II

Dearest Student. This web page is a set of questions I call Detailed Intended Learning Outcomes For Organic Chemistry (Part II). Some time ago I asked myself, "Bob, what do you think are the key questions that you hope students will be able to answer after taking Chemistry 248 at St. Olaf College?" So here you have them. Some are very simple; some require more thought. All are good questions to be thinking about as you read, discuss, and master the practical aspects of organic chemistry. They are discussion starters and review tips. There are no answers here (though there are some clues). The questions are here to help you focus on what's important (to me, at least!) and organize your learning process. The questions are grouped into topics. Bite-size chunks. Take them a few at a time. Don't feast on them all at one sitting!

(preliminary version 2021.01.15 feeback: Bob Hanson)