Synthesis of potassium (2R)-2-O-α-D-mannopyranosyl-(1→2)- α-D-glucopyranosyl-2,3-dihydroxypropanoate: A naturally compatible solute

摘要

An expedient synthesis of the potassium salt of (2R)-2-O-α-D- mannopyranosyl-(1→2)-α-D-glucopyranosyl-2,3-dihydroxypropanoic acid (MGG)a-a recently isolated, rare, compatible solutea-was accomplished. A bis-acetal-protected thioglucoside, 6-OTBDPS, with a 2-OH group was used as the acceptor in the first glycosylation reaction with tetraacetylmannosyl trichloroacetimidate, and as the donor in the glycosylation reaction with the glycerate derivative. The α anomer was the only product of both glycosylation reactions, as expected for the formation of the α-mannoside. The formation of the 1,2-cis glucoside was more challenging.