Intramolecular Nitrogen Delivery for the Synthesis of C-Glycosphingolipids. Application to the C-Glycoside of the Immunostimulant KRN7000

[Image: see text] The key reaction in this approach to C-glycosphingolipids is the stereoselective iodocyclization of a sugar-linked homoallylic carbonimidothioate. E and Z reaction substrates were assembled in a convergent fashion via an alkene metathesis strategy and exhibited the same alkene facial selectivity in the iodocyclization irrespective of alkene geometry, although the E alkene was found to be less reactive.