Nontraditional Synthesis of Disaccharides via Acyclic Vinylic Ether Intermediates: Catalytic C–O Cross-Coupling as the Enabling Link

High Resolution Image Download MS PowerPoint Slide We describe complementary methods for synthesizing acyclic vinylic ethers from two carbohydrate-derived synthons. We compare a nonstereoselective olefination approach with a stereoselective catalytic C–O cross-coupling method, preparing 1,2-disubstituted vinylic ethers with complexity on both sides of the ether linkage. Upon epoxidation/ in situ oxacyclization of acyclic vinylic ethers, we synthesized disaccharides with α- d -galacto-, α- d -talo-, β- d -allo-, and α- d -altropyranoside stereochemistry, from d -lyxose and d -ribose precursors. Stereoselective CuI/CyDMEDA-catalyzed C–O cross-couplings offer considerable potential for broadly implementing this nontraditional strategy for glycoside synthesis.