Direct Synthesis of Unsaturated Sugars from Methyl Glycosides

Transformation of sugars without protection of the OH groups is an ideal method and a powerful tool for biomass utilization, and particularly, unsaturated sugars are a promising target because they can be transformed to versatile chemicals because of the olefin group. Herein, we demonstrated direct transformation of various methyl glycosides, which can be easily obtained from sugar derivatives, without protection of the OH groups to the corresponding unsaturated sugars with maintaining their original stereostructures in high selectivities and yields (up to 90%) using ReO_x-Au/CeO₂ catalyst at low H₂ pressure (≤1.2 MPa) by deoxydehydration.