Topic 38: Elimination - Alkenes

38.1What constitutes a β-elimination reaction?
 
38.2What are the three types of disubstituted alkenes?
 
38.3Why do we classify cis and trans isomers as diasteriomers?
 
38.4What is the trend in stability of alkenes, based on substitution (mono, di, tri, tetra)?
 
38.5What is the general “explanation” for this trend (using Google)? Is this the explanation your author gives?
 
38.6What is hyperconjugation, and how might it explain the trend in stability of substituted alkenes?
 

Topic 39: Elimination - The E2 mechanism

39.1What are the essential features of the E2 mechanism? Why “2” here?
 
39.2What special alignment of atoms is necessary for (or at least, strongly favors) an E2 mechanism?
 
39.3Besides strong RO– bases, what nitrogen-containing weak bases are popular for effecting E2 reactions? Your author may refer to these as strong bases, but technically they are not strong bases; all amines are weak bases.]
 
39.4Which nitrogen atom of DBN accepts the proton? Why this one and not the other?
 
39.5What is so special about DBN and DBU? [HINT: What makes them poor nucleophiles? And what does that have to do with this question?]
 
39.6Which solvent - nonpolar, polar aprotic, or protic - best promotes E2 reactions? Why?
 
39.7What do these abbreviations stand for: DMF, DMSO?
 
39.8If you needed to carry out an E2 reaction in the lab, why would you perhaps not choose DMSO as a solvent for the reaction? (two good reasons)
 

Topic 40: Elimination - the Zaitsev Rule and reaction selectivity

40.1What is the Zaitsev/Saytzeff/Zaitseff Rule?
 
40.2Why can't people seem to agree on how to spell Zaitsev's name?
 
40.3When does the Zaitsev Rule apply? When does it not?
 
40.4What does it mean for a reaction to be regioselective?
 
40.5What does it mean for a reaction to be stereoselective?
 
19 questions
364 questions for Organic I

364 Questions for Organic I

Dearest Student. This web page is a set of questions I call Detailed Intended Learning Outcomes For Organic Chemistry (Part I). 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 247 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)