Exploring the Wittig Reaction: A Collaborative Guided-Inquiry Experiment for the Organic Chemistry Laboratory

A two-week guided-inquiry Wittig reaction experiment was developed for the undergraduate organic laboratory. In week one, groups are assigned a research topic to investigate the Wittig reaction, such as the effect that substituents on the carbonyl compound may have on E/Z selectivity. A hypothesis, controlled by a provided chemical list, is developed along with a series of experiments to test predictions. For example, more Z isomer might be expected from a steric effect of methyl substituents on o-, m-, and p-tolualdehydes. In the second week, students perform reactions by adapting a general procedure and obtain E/Z selectivities from H-1 NMR. Compiled data are shared online as groups aim to support or refute their hypotheses. As a result of the experiment, students gain insights into the nature of science and the analysis of data as well as a better understanding of the research process.