Iodine Promoted Glycosylation with Glycosyl Iodides: α‐Glycoside Synthesis

Abstract

Glycosidation of fully acetylated glucopyranosyl iodide with methanol under the influence of iodine gave α‐glucoside selectively. Use of less reactive acceptors led to the formation of α/β‐mixtures. Glycosylations with fully benzoylated glucosyl iodide yielded β‐glucosides only. In contrast, iodine-promoted glycosylation of serine and threonine with 2‐azido‐2‐deoxy‐glycosyl iodides, easily obtained in three steps, proceeded smoothly, resulting in only α‐linked products in high yield in most cases.

Keywords:

• Glycosyl iodine
• Iodine
• Glycosylated amino acids
• α-glycosylation

Acknowledgment

This work was supported by an EU Marie Curie Intra‐European Fellowship (to R. v W) and by the Weston Foundation. We thank the UK EPSRC Mass Spectrometry Service Centre, Swansea, for invaluable support.