Tag: SN1/SN2/E1/E2

Seeing the Big Picture

As the semester comes to a close, I have been reflecting on my lectures and experiences with a mechanistically organized course. The Karty text has presented many different types of reactions; from all of the reactions, I want the students to be aware of the central theme in ALL organic mechanisms. In every step, there

Read More

Time Well Spent

Teaching a mechanistically organized course has many benefits. For example, I am able to spend less class time on nomenclature. This semester, I assigned nomenclature “chapters” 1-3 for the students to read outside of class, arranging them among chapters 1–10 of the text. This meant that I spent only 25% of lecture time explaining nomenclature.

Read More

Cutting off the Tail

testing

Favorite First-Semester Chapter: Chapter 9

My favorite chapter to teach in first-semester organic chemistry has to be Chapter 9 (“Nucleophilic Substitution and Elimination Reactions 1”) from Karty’s text. The introductions of S­N2/E2 and SN1/E1 reactions begin in Chapters 7 and 8, respectively, but Chapter 9 puts these reactions to the test and suggests to the students that reactions do not

Read 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

Read More

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

Read More

Teaching Solvent Effects Early Helps Keep Students’ Heads From Spinning

We started Chapter 9 in class a couple weeks ago, where we learn how to predict the outcome of the SN1/SN2/E1/E2 competition. Similar to how it’s done in most books, we do this by first learning about the major factors that influence the rate of each reaction in this competition. But unlike other books, this

Read More

Teaching the Mechanism Means Testing the Mechanism

Exam questions are a primary medium by which students learn what their instructor values most in the course. If we evaluate what we value, questions should test the mechanism and thus emphasize conceptual understanding, utilize real applications, and require deep thinking. And for me, the most important reason to pose mechanistic questions is to see

Read More

Mechanisms and Higher Order Cognitive Skills

I have been teaching organic chemistry with a mechanistic approach for a long time. Unfortunately, the book that I used prior to Karty tried but ultimately dropped this approach midway through the second semester of topics. In Joel’s text, mechanisms and thinking through a different lens pervade, which has prompted a number of my students

Read More

MCAT-2015 is Here

The new year traditionally brings a time for both reflection and looking forward. For teachers of organic chemistry everywhere, this past year stands out more than most. After years of planning, MCAT-2015 is finally upon us. I previously wrote about the challenges and opportunities this change holds for us and how we, at Middlebury College,

Read More