Ah yes, it is that time of year again; a seven week coast to the Organic Chemistry II finish line. All the elementary steps have been introduced and discussed multiple times and it feels like review from here. Most texts seem to end with reactions like Aldol condensation and Robinson Annulation. A functional group approach … Continue reading All Downhill After the Aldol
When to Introduce Conjugate Addition: Sometimes More is More
There were two places in Joel’s text that surprised me: where 1,2 versus 1,4 addition to a conjugated diene appeared—Chapter 11—and where direct versus conjugate nucleophilic addition to polar pi bonds appeared—Chapter 17. Both of these chapters introduce basic concepts and then expand all the way to complex applications, much further than a functional-group organized … Continue reading When to Introduce Conjugate Addition: Sometimes More is More
How the Ten Elementary Steps Unified My Course
For years I told my students they shouldn’t merely memorize a list of reactions. But what were my actions really telling them? In the last textbook I used, the alkene chapter began with nomenclature, then covered Markovnikov addition of H-X and water, halogenation and halohydrin formation, and ended with hydroboration/oxidation. The next chapter that covered … Continue reading How the Ten Elementary Steps Unified My Course
Taking the Enolate off the Pedestal
I’ve noticed over the years that when I put a “name” on something, students tend to panic. We will be doing just fine with SN2 reactions, but when I suddenly name it the Williamson Ether Synthesis, my students become very concerned, as if it’s some completely different concept. Whenever I bring up the Williamson Ether … Continue reading Taking the Enolate off the Pedestal
Six Things Students Should Be Able to Do upon Completing Chapter 7, and One Thing They Shouldn’t
In my previous post, I described how happy I’ve been with my students’ ability to process the relatively complex interplay between kinetics and thermodynamics to understand the outcome of a competing set of chemical reactions. The specific example I gave involved the competition between transesterification and the Claisen condensation reaction, and that got me thinking … Continue reading Six Things Students Should Be Able to Do upon Completing Chapter 7, and One Thing They Shouldn’t
Ending on a Good Note
A few days ago I returned the second exam of organic II, the bulk of which covered nucleophilic addition and nucleophilic addition-elimination reactions. The following day, a student came to my office to ask questions about the problems she missed. This particular student got off to a rocky start at the beginning of the semester … Continue reading Ending on a Good Note
Demystifying Enolate Chemistry
In my mind, enolate chemistry is one of the highlights of the second-semester organic chemistry course. Granted, the list of named enolate-based reactions (Aldol, Claisen, Michael, Robinson, etc.) can be daunting to students. Nevertheless, the importance of enolate chemistry in biochemical processes (glycolysis, gluconeogenesis, fatty acid biosynthesis), as well as in the synthesis of compounds … Continue reading Demystifying Enolate Chemistry
Improvements on Retrosynthetic Analysis
Success in organic chemistry is heavily reliant on a student’s ability to identify patterns. Until recently, I organized my course by functional group. It was only after I adopted Joel Karty’s approach that I recognized that the variety of reactions used to synthesize each functional group can vary widely and that this variance makes it … Continue reading Improvements on Retrosynthetic Analysis