Topic 7: Electrophilic aromatic substitution

7.1What is the mechanism of electrophilic aromatic substitution? [Note that when writing mechanisms, it is never necessary to draw more than one resonance contributor. You can do that if you want (as long as you add […] around them), but it is not necessary. Your author does not show these brackets, but you must if you decide to show all resonance contributors.]
 
7.2How many steps are involved in an electrophilic aromatic substitution, ignoring production of the electrophile?
 
7.3Which is the faster reaction — The addition of the electrophile, or the loss of H+?
 
7.4Are the conditions for electrophilic aromatic substitution acidic or basic? Why?
 

Topic 8: Halogenation, nitration, and sulfonation

8.1What is the function of the Lewis acid in these reactions?
 
8.2You know that “H+” does not exist and that it is just an abbreviation. What is it an abbreviation for? [Hint: Most organic reactions are not carried out in water.]
 
8.3If I told you that “Br+” is an abbreviation we can use in an aromatic bromination, what would that be an abbreviation for?
 
8.4Write the mechanism for a bromination reaction using the abbreviations “H+” and “Br+”, using no curvy arrows and only one resonance contributor for the intermediate cation.
 
8.5Why are only Br2 and Cl2 used in aromatic halogenation OF BENZENE, never I22 or F22?
 
8.6Is this a general statement, or is iodination of other aromatic compounds possible? How do you know?
 
8.7What is “E+” in an aromatic nitration? What is the recipe for making it?
 
8.8What is “E+” in an aromatic sulfonation? What is the recipe for making it?
 

Topic 9: Friedel-Crafts alkylation and acylation

9.1What is an “alkyl” group?
 
9.2What is “E+” in a Friedel-Crafts alkylation? (That is, why the quotes?) What is a recipe for making it?
 
9.3What are three other recipes for creating alkyl cations that you learned from last semester?
 
9.4What is a complication of the Friedel-Crafts alkylation that is always a concern when a mechanism involves alkyl cations?
 
9.5(Looking ahead) Alkyl groups on a benzene ring accelerate the F-C alkylation reaction. What is the implication of this, since the product of the F-C alkylation of benzene adds an alkyl group to the benzene ring?
 
9.6What is an “acyl” group?
 
9.7What is “E+” in a Friedel-Crafts acylation? What is a recipe for making it?
 
9.8What problem of the F-C alkylation does F-C acylation solve?
 
9.9(Looking ahead) Adding an acyl group to a benzene ring slows down the F-C acylation reaction. How does this also make F-C acylation more useful than F-C alkylation?
 
9.10What synthetic limitation (bonus?) is introduced by F-C acylation that is not present in F-C alkylation?
 
9.11What does intramolecular mean? What is an example of an intramolecular Friedel-Crafts acylation?
 
23 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)