NAP ether mediated intramolecular aglycon delivery:: A unified strategy for 1,2-cis-glycosylation

A methodology directed towards the stereoselective construction of 1,2-cis-glycosides through naphthylmethyl (NAP) ether mediated intramolecular aglycon derivery (IAD) has been developed. Stereospecific constructions of various 1,2-cis linkages, as in beta-mannopyrano-, beta-arabinofurano-, and alpha-glucopyranosides, were achieved through NAP-IAD. This methodology was successfully applied to the synthesis of Glc alpha(1 -> 2)-Glc alpha(1 -> 3)-Glc alpha(1 -> 3)Man (Glc(3)Man(1)), the non-reducing terminal structure of the tetradecasaccharide Glc(3)Man(9)GlcNAc(2), a common precursor of all N-linked glycans. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008).