Allyl protecting group mediated intramolecular aglycon delivery(IAD) of glycosyl fluorides

摘要

Stereospecific 1,2-cis-glycosylation of 2-O-allyl protected glucosyl and mannosyl fluorides can be achieved via a sequence of allyl isomerization,N-iodosuccinimide mediated tethering,and intramolecular aglycon delivery (IAD).Fluoride is advantageous as an anomeric leaving group sine extended reaction times can be employed to tether hindered aglycon alcohols without competitive anomeric activation.Tin(II) chloride mediated intramolecular glycosylation furnishes the desired #alpha#-glucosides and #beta#-mannosides in an entirely stereoselective manner.