Topic 12: Limitations of electrophilic aromatic substitution

12.1Aniline and phenol are too reactive under the standard conditions of halogenation. What happens instead?
 
12.2What is the solution to this problem?
 
12.3Neither Friedel-Crafts alkylation nor Friedel Crafts acylation can be carried out on aromatic systems that already have strong electron-withdrawing groups. (Note that “strong” here excludes halogens.) What is the explanation of this?
 
12.4F-C alkylation and F-C acylation also do not work for aniline. Why is that?
 
12.5(Looking ahead) The solution in cases involving aniline and phenol is to first “tone them down” by treatment with acetyl chloride (Section 22.8), as shown below, where “X” is the benzene ring. See discussion. Why does this solve the problem? What additional potential problem does it raise?



 
12.6What is polyalkylation, and when, specifically, is it a problem?
 
12.7Which group wins if two directing groups already on a benzene ring oppose each other‘s influence?
 

Topic 13: Additional reactions of aromatic compounds

13.1What is nucleophilic aromatic substitution?
 
13.2What sort of substitutents are required for nucleophilic aromatic substitution?
 
13.3What is benzyne? What conditions generate benzyne? What makes it such a reactive intermediate?
 
13.4What is benzylic bromination? When could it be useful in a synthesis?
 
13.5What synthetic problem does benzylic oxidation with KMnO4 solve?
 
13.6What are the Clemmensen and Wolff-Kishner reductions, and what synthetic issue do they solve?
 
13.7Why is the reduction of a nitro group to an amine a particularly useful reaction synthetically?
 
13.8(Looking ahead) The reaction of a Grignard reagent with CO2 is mentioned in Section 20.14. How could that be extremely useful here from a synthetic point of view?
 
15 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)