Methyl 1,2-Orthoesters in Acid-Washed Molecular Sieves Mediated Glycosylations

Abstract

Glycosylation of alcohol derivatives with D-mannose and D- glucose derived methyl 1,2-orthobe nzoates can be promoted by commercially available acid-washed 300 molecular sieves (AW-MS), which functions both as promoter and as a drying agent in an operationally simple process. In this manner, glycosides can be obtained in good to excellent yields at room temperature, reflux, or under microwave (MW) heating. The usefulness of the process has been shown with the prepar ation of some diterpene glycosides.