Choosing to Teach the Mechanism

When it became clear that we would be changing texts for organic chemistry, most of my colleagues and I began dreading the long decision and transition process. We all use the same textbook and choose it by consensus. There are about seven faculty members in our department who teach in the organic chemistry series. We come from diverse educational backgrounds and have significantly different teaching styles. Consensus building with a large and diverse group like this can be a considerable challenge. This year’s selection process was daunting. We had narrowed down a long list of options to two very different candidates: a traditional text and Joel Karty’s mechanistically-organized text.

The traditional text was very similar to the text we were moving away from. We were looking for a more affordable textbook option that still met our pedagogical needs. The mechanistically-organized text represented a significant departure to the way each of us had structured our in-class time and problem sets. This is not to say that organizing organic chemistry material by mechanism was a foreign concept to us. Most of us encourage students to create a “reaction notebook.” For a portion of this notebook, we encourage students to organize the reactions by mechanism. We have found that our undergraduate students are able to complete this task with mixed success and have found it to be a useful exercise.

But a wholesale change to a mechanistic approach would be a large commitment on the faculty members’ part. It would mean completely revamping our lectures, in-class exercises, problem sets, exams, and other activities. I had to admit to hearing the siren’s song of remaining with the traditional approach—it certainly would have been easier, more comfortable for my teaching style, and would allow me to use my valuable preparation time for other purposes.

However, when I thought about what my students actually needed, the mechanism-based organization just made more sense to me. Our students struggle with seeing bigger patterns of mechanistic pathways. They are able to easily identify first steps or common steps, but, at least initially, fail to see the broader implications of similar reaction types. Without the understanding of this, it becomes easy for our students to fall into the trap of seeing every reaction as an individual reaction. It was my hope that a mechanistic approach in the text, with my continued emphasis in the classroom, would help our students overcome these hurdles. I believed that the painful change would be worth the effort, and I advocated for this with my colleagues.

After several discussions, we did decide to adopt Karty. We have completed one full year of using the text and I’m happy to report the change has been mostly positive. I have enjoyed reevaluating my teaching in the context of a mechanistic organization. I may have dreaded the change, but it has been satisfying for me professionally. In upcoming posts, I will discuss how I’ve been using a mechanistic organization in my course.

-Anne Wilson, Butler University

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