High Pressure Mediated Asymmetric Diels-Alder Reaction of Chiral Sulfinylacrylate Derivatives with Furan and 2-Methoxyfuran

Asymmetric Diels-Alder reaction of c h i d sulfmylacrylate derivatives (1 and 2) with furan (3) and 2-methoxyfuran (4) proceeded under high pressure (1.2 GPa) conditions to give endo cycloadducts (6c-f).The absolute configuration of adduct (6) was confirmed by conversion of 6e to (-)-COTC (9).Optically pure 7-oxabicyclo[2.2.l]hept-5-ene derivatives are key intermediates in the chiral synthesis of biologically active and/or natural products.lAlthough this bicyclic framework is available by the asymmetric Diels-Alder (D-A) reaction of furans with more powerful c h i d dienophiles under ordinary