Versatile Synthesis of Diaminoxylosides via Iodosulfonamidation of Xylal Derivatives

d-Xylose is a special monosaccharide found in various organisms, which is characterized by conformational dynamics between different pyranose ring forms depending on the substitution pattern. With a perspective to study the conformational equilibria of xylosides and eventually use them as conformational switches, we sought an entry into a flexible synthesis of 2,4-diamino-xylosides. In particular, we synthesized 4-bromophenyl 2,4-diamino-3-O-(4-bromophenyl)-β-d-xyloside from l-arabinose utilizing a concomitant epimerization and differentiation at position 4 and iodosulfonamidation of a difunctional xylal at a later stage of the synthetic pathway. This strategy provides xylose derivatives with high stereochemical precision and a high degree of functionalization. The obtained xylose derivatives are of interest as conformational hinge molecules and as orthogonally protected triamino scaffold molecules.