Ring Flips of Chair Conformations

I’m back in the lecture classroom again this semester — I was on research leave Spring 2018 and have been teaching biochemistry labs and my chemical biology discussion-based course in Fall 2017/2018. I have two sections of the first semester of organic chemistry (CHEM 205 at UR). Many of the students are first-year students and so when the light-bulb clicks on, it shows all over their face.

One of my favorite demonstrations is holding up a color-coded model of cyclohexane and performing a ring flip. I will put all blue groups in the axial positions and all green groups in the equatorial positions. When the ring flip happens, they switch directions. I ask the students to watch closely, to focus on the structure, and then I do the flip. There is always an exclamation, a sense of awe (and maybe confusion to how I did it), but it gets the point across so clearly.

A week from today, the students have their first hour exam. Please send motivational thoughts toward Richmond during the morning, especially if they are related to chair structures of cyclohexanes.

~jap