Acid-Catalyzed O‑Glycosylation with Stable Thioglycoside Donors

Two classes of thioglycoside, 4-(4-methoxyphenyl)-3-butenyl­thioglycosides (MBTGs) and 4-(4-methoxyphenyl)-4-pentenyl­thioglycosides (MPTGs), undergo acid-catalyzed O-glycosylations with a range of sugar and nonsugar alcohols at 25 °C. Electron density at the styrene alkene is critical for reactivity while sugar protecting group patterns have a minimal effect. In contrast with most methods for thioglycoside activation, acid-catalyzed activation of MBTGs is compatible with electroneutral alkenes.