Synthesis of Tetrahydro-2-(2-propynyloxy)-2H-pyran: Illustrating Markownikov Addition, Protecting Groups, and Advance 1H-NMR Phenomena

A procedure for the preparation and purification of tetrahydro-2-(2-propynyloxy)-2H-pyran is reported for use as an introductory organic laboratory exercise. Synthesis of the target compound illustrates Markownikov Addition and formation of a THP-ether protecting group, produces an acetal functional group, and models a recently developed resin used in combinatorial chemistry. Purification of the target compound via flash column chromatography exposes students to a central technique of modern synthetic methodology. Analysis of the target compound via 1H NMR introduces non-first order coupling (i.e. AB quartet) and long range (i.e. 4-bond) coupling.