I did not realize my commitment to traditions—in my personal life and in the classroom—until recently. In my personal life, I discovered that I was married to a person who did not know that: Christmas trees are decorated while listening to Christmas music and not with a basketball game on in the background; salads are eaten after the main meal; there is no TV in the morning; and soda is a restaurant-only drink. In the classroom, my closely-held tradition was to introduce free radicals first. Traditions are fine, important things, which is why we observe them. But at what point do we rethink traditions? Are we traditionalists open to new, improved ideas?
Two-cycle organic chemistry is a pedagogical approach that has gained in popularity over the last couple decades. It’s a rather simple idea: The first semester course is treated as something of a survey, dealing primarily with the fundamentals, whereas the second semester revisits many of the same topics from the first semester, but treating them in greater depth. This two-cycle approach seems to be particularly advantageous for institutions whose biology majors (and other nonmajors) are required to take just one semester of organic chemistry. With less depth in each first-semester topic, nonmajors are exposed to more topics, and the material, moreover, can seem less intimidating. For chemistry majors and pre-health students, a significant benefit might come from the way that second-semester material is treated. Revisiting the first semester topics in greater depth represents an inherent review of the earlier material, allowing students to stay fresh on that material throughout the entire year. And because the second semester maintains a focus on the more challenging material, students should be better prepared for the final exam.
Despite these potential benefits, instructors who teach (or want to teach) a two-cycle organic course face a significant problem: Which book to use. Continue reading
This unique chapter is the game changer for how students perceive organic reactions. Whenever I discuss Joel’s textbook with colleagues, this chapter is the first aspect of the book that I mention.
Chapter 7, “An Overview of the Most Common Elementary Steps,” briefly surveys ten steps:
- Proton transfer
- Bond formation (coordination)
- Bond breaking (heterolysis)
- Addition of a nucleophile to a polar pi bond
- Elimination to form a polar pi bond
- Addition of an electrophile to a nonpolar pi bond
- Elimination of an electrophile to form a nonpolar pi bond
- Carbocation rearrangements
This survey covers the elementary steps that students will see in a reaction mechanism until they study pericyclic reactions and reactions involving free radicals.