Diethyl Ether → D-Galactal

Beteiligte Stoffe

Reaktionsschritte

To 2.00 g (2.47 mmol) of lactal carbonate 8c was added 4.44 g (9.86 mmol) of fucosyl fluoride 9c. The mixture was azeotroped 5 times with benzene and placed under high vacuum for two hours. Under an argon atmosphere 2.77 mL (12.33 mmol) of di-tert-butyl pyridine and 16 mL of dry ether were added. 2.0 g of freshly activated 4 Å molecular sieves were added and the mixture stirred one hour at room temperature. In an argon glove bag, 2.34 g (12.33 mmol) of stannous chloride (SnCl2) and 2.56 g (12.33 mmol) of silver perchlorate (AgClO4) were added. The flask was equipped with a reflux condenser and the reaction brought to reflux for 72 hours. The reaction was quenched with 5 mL of saturated bicarbonate and filtered through a pad of celite. Diluted with 50 mL ethyl acetate and washed 2 times with saturated bicarbonate, 2 times with sat. copper sulfate and 2 times with sat. brine. The organics were dried over MgSO4 and concentrated. Flash chromatography in 20% ethyl acetate/hexanes afforded 2.10 g (51%) of a white foam 10 c:

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