Synthesis of 7-Oxabicyclo[2.2.1]heptane and Derivatives

Nature provides a number of 7-oxanorbornanes (7-oxabicyclo[2.2.1]heptanes), many of them with interesting biological activity. There are several routes to their synthesis; the most common remains the Diels–Alder reaction of furans with olefinic or acetylenic dienophiles. Several 7-oxanorbornane derivatives can be prepared enantiomerically enriched readily. They are extremely useful chirons for the total asymmetric synthesis of all kinds of natural products and bioactive compounds such as rare sugars and analogues, monosaccharides, and disaccharide mimetics. There are several methods for the C–O and C–C bond cleavage of 7-oxanorbornanes. Because of their bicyclic structure, 7-oxanorbornanes permit to generate a wide chemodiversity in a highly stereoselective manner.