Scope and Limitations of 2‑Deoxy- and 2,6-Dideoxyglycosyl Bromides as Donors for the Synthesis of β‑2-Deoxy- and β‑2,6-Dideoxyglycosides

Abstract

It is shown that 2-deoxy- and 2,6-dideoxyglycosyl bromides can be prepared in high yield (72–94%) and engaged in glycosylation reactions with β:α selectivities ≥6:1. Yields of product are 44–90%. Fully armed 2-deoxyglycoside donors are viable, while 2,6-dideoxyglycosides require one electron-withdrawing substituent for high efficiency and β-selectivity. Equatorial C-3 ester protecting groups decrease β-selectivity, and donors bearing an axial C-3 substituent are not suitable. The method is compatible with azide-containing donors and acid-sensitive functional groups