Glycosidation Allyl chloroformate

Glycosidation Allyl chloroformate, 9 Boron trifluoride etherate, 43 Silver(I) tetrafluoroborate, 273 Silver (I) trifluoromethanesulfonate, 274 Thallium zeolites, 296 Tin(II) trifluoromethanesulfonate, 301 Trichloroacetonitrile, 321 Grignard reactions and reactions of... 

A mixture of the glycoside 17 (1 mmol) and dibutyltin oxide (1 mmol) in benzene was refluxed for 16 h with azeotropic removal of water. The solution was evaporated to ca. 25 mL, tetrabutylammonium iodide (1 mmol) and allyl bromide (0.5 mL) were added, and the mixture was heated at 60 °C for 8 h. Evaporation to dryness gave a residue which was processed by column chromatography on silica gel (chloroform/methanol, 95 5). Crystals (18, 85%), m.p. 105 °C (Et20), [a]D -20° (2.0, dichloromethane). 

---