Facile Epimerization of (+)-Sclareolide: A Versatile Experiment for Laboratory Education

An experiment to teach the concept of epimerization in advanced practical settings is presented in a versatile format suitable for those interested in developing their laboratory curriculum and activities. The experiment was implemented at two different locations, namely, the Faculty of Pharmacy at the University of Helsinki, in Finland (UHEL), and the School of Pharmacy at the University College Cork (UCC), in Ireland. At both locations, students were able to generate and isolate the epimer of (+)-sclareolide 1 in high yields and purity and in short reaction times using our newly developed catalytic procedure mediated by bismuth(III) triflate. The laboratory environments were designed to be accessible to all students regardless of their prior knowledge of chemistry. Both supportive and procedural study guides are presented, which enabled active learning of epimerization, the principles of catalysis, and Brønsted acidity in organic reaction mechanisms, as well as carbocation-mediated reaction mechanisms and stereochemical configuration in general. A variety of assessment tools were used to collect student feedback on the laboratory sessions, which can guide and help to further enhance future laboratory sessions using our protocol. This work situates epimerization in a real-world context, which should increase student motivation and interest in learning about the topic.