A Coumarin Mystery–The Case Of The Missing Methyl Groups

This article describes a discovery-oriented undergraduate experiment positioned as a “mystery” in an upper-level mechanistic organic course at the University of Toronto. Students individually undertake a trivial synthetic reaction between an aromatic salicylaldehyde and 2,2-dimethyl-1,3-dioxane-4,6-dione (Meldrum’s acid), without being informed of the product structure. They work collaboratively during the reaction time to propose both a likely product and operative mechanism given the experimental conditions and physical observations made. Finally, students obtain spectroscopic information about their synthesized compound and justify whether their predictions were sound (or otherwise).