Stereospecific synthesis of 1,2-cis glycosides by vinyl-mediated IAD

Org Lett. 2004 Oct 14;6(21):3797-800. doi: 10.1021/ol048427o.

Abstract

[reaction: see text] Stereospecific 1,2-cis glycosylation of 2-O-vinyl thioglycosides, synthesized from the corresponding alcohols by Ir-catalyzed transvinylation with vinyl acetate, is achieved by iodine-mediated tethering of a range of primary and secondary carbohydrate acceptors, followed by intramolecular aglycon delivery (IAD). The use of such an intramolecular glycosylation strategy furnishes the desired alpha-gluco and beta-manno disaccharides in an entirely stereoselective manner.