Tandem organochromium-coupling and epoxide ring opening: a direct approach for the synthesis of cyclic ethers

A two-step protocol for the convergent formation of cyclic ethers has been demonstrated. This involves the chemoselective 1,2-addition of vinylchromium species to a 4,5-epoxy aldehyde to generate γ,δ-epoxy alcohols followed by acid-induced transetherification to generate substituted tetrahydrofuran and pyran products.