A New and Practical Procedure for the Preparation of the Glucohexatose Phytoalexin Elicitor

摘要

The phytoalexin elicitor β-(1 → 3)-branched β-(1 → 6)-linked glucohexatose has been regio- and stereospecifically synthesized by coupling of the 3,6-branched gluco-trisaccharide Schmidt reagent 10 with a mixture of multiol 3,6-branched gluco-trisaccharides 13 which consists of free 5,6'-OH trisaccharide, free 5,2',6'-OH trisaccharide, free 5,3',6'-OH trisaccharide and so on. The compounds 10 and 13 were prepared from 1,2:5, 6-di-O-isopropylidene-α-D-glucofuranose, 2,3,4,6-tetra-O-benzoyl-α-D-glucopyranosyl trichloroacetimidate, and 2,3,4,6-tetra-O-acetyl-α-D-glucopyranosyl trichloroacetimidate through regio- and stereoselective manners.