Synthetic studies on glycosphingolipids from the Protostomia phyla: syntheses of arthro-series glycosphingolipids

Abstract

Glycosphingolipids isolated from larvae of the green-bottle fly, Lucilia caesar, have quite unique structures containing GlcNAcβ-(1→3)-Man and GalNAcβ-(1→4)-GlcNAcβ-(1→3)-Man. We have synthesized two glycosphingolipids, β- d-GlcNAc p-(1→3)-β- d-Man p-(1→4)-β- d-Glc p-(1→1)-Cer and β- d-GalNAc p-(1→4)-β- d-GlcNAc p-(1→3)-β- d-Man p-(1→4)-β- d-Glc p-(1→1)-Cer. A key reaction in the synthetic sequence is the application of the intramolecular aglycon delivery (IAD) approach for the synthesis of the β-mannopyranosidic linkages.