C-glycosphingolipid precursors via iodocyclization of homoallyic trichloroacetimidates

•α-C-glycosyl-linked homoallylic tricloroacetimidates were prepared.•Iodocyclization of these substrates gave highly substituted C-linked iodo-oxazines•E- and Z-alkenes favored anti and syn 1,3-amino alcohol motifs, respectively.•These products are potential precursors to C-glycosides of the glycolipid KRN7000.

The iodocyclization of homoallylic trichloroacetimidates derived from α-C-allyl galactoside were investigated. In line with the stereochemical trend observed for less substituted non-glycosylated frameworks, E and Z substrates delivered stereoselectively the 1,3-anti and 1,3-syn amino alcohol motifs, respectively. These products are advanced precursors to C-glycosides of the potent immunostimulatory glycolipid KRN7000.

Graphical abstractThe iodocyclization of homoallylic trichloroacetimidates provides precursors to C-linked glycolipids.Figure optionsDownload full-size imageDownload as PowerPoint slide