When I first perused the Preliminary Edition of Joel Karty’s textbook, I was apprehensive about the organization and whether students would really benefit from this change. Midway through the first semester it became clear to me that a mechanistically organized course creates a broad-based platform that gets to the heart of what we are trying to teach students—problem solving skills. When I had organized my course by functional group, the broad number of reaction types meant that students gradually let the reactions wane over time because of a lack of practice. I now believe that when students spend their efforts on mastering common elementary steps they’re less likely to forget them because they’re constantly reinforced throughout two semesters of curriculum.
Using a simpler classification system for analyzing reactions is beneficial to all students. Last semester, around the same time that the ten most common elementary steps were introduced in lecture, the class was also completing a Fischer Esterfication reaction in lab in order to synthesize banana oil. While reactions were refluxing, I challenged students to see if they could complete the moderately advanced mechanism for this reaction. I gave them only the hint that no basic intermediates could be created since they were using acidic conditions. Several of my top students were able to correctly draw this multistep mechanism without ever seeing it in class.
Most other groups were able to determine that the reaction must begin with a proton transfer, and with the hint of using nucleophilic addition and elimination they were able to complete this mechanism (in Week 8 of the course). This exercise also solidified the importance of proton transfers as several students commented about how many we used in this mechanism. Many students intuitively asked if this many proton transfers were common for other mechanisms. At such an early point in the course, students were able to see this common trend and then begin the process of analyzing reaction conditions in order to understand where to begin solving a problem.
Many of my exams have a number of dreaded “fill-in-the-box” problems where students are asked to fill in the reagents, starting materials, or products that best complete a transformation. Past performance has shown that students struggle with these application-based problems. When using Karty’s book, students still struggle equally with these fill-in-the-box problems, but I have noticed an overall improvement on questions that ask them to draw out a mechanism. Students are even able to do well on mechanism drawing problems where I ask for the mechanism without first giving the product.
Many of my students will never have to conduct a Williamson ether synthesis or anti-Markovnikov elimination. It is even likely and understandable that this terminology will eventually fade from their lexicon. However, the problem-solving skills developed by students who take an organic course organized by mechanism are not as likely to fade, and these learned skills will provide greater avenues to success to students at all ability levels.
— James Wollack, St. Catherine University
James Wollack teaches at St. Catherine University and is currently class-testing the Preliminary Edition of Joel Karty’s forthcoming textbook. Click here to learn more about Prof. Wollack.