Intramolecular nitrogen delivery for the synthesis of C-glycosphingolipids. Application to the C-glycoside of the immunostimulant KRN7000

Abstract

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. © 2014 American Chemical Society.