Aryl Sulfonates in Inversions at Secondary Carbohydrate Hydroxyl Groups: A New and Improved Route Toward 3-Azido-3-deoxy-beta-D-galactopyranosides

A method of using benzenesulfonates and imidazylates as leaving groups at the secondary C3 galactopyranose carbon, instead of the commonly used less stable triflate leaving group, to facilitate scale-up and improve reproducibility is disclosed. The benzenesulfonates and imidazylates were proven to be significantly more stable than the corresponding triflates and the method was used to devise an improved route toward 3-azido-3-deoxy-beta-D-galactopyranosides.