Investigation of epimer formation in amide coupling reactions: an experiment for advanced undergraduate students

An experiment is described to investigate how the choice of coupling agent and reaction conditions affects the ratio of epimers formed in the sensitive amide-coupling reaction between N-Boc or N-benzoyl (R)-phenylglycine and (S)-valine methyl ester. The experiment, which is suitable for third-year undergraduates, is designed to teach about important synthetic methods and reaction mechanisms, and to develop skills in designing experiments, data analysis, and team work