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The octopus type oligo-hydroxypropylene glycol β-D-glucopyranosides were successfully synthesized in this studies: the sterospecific compound of allyl 2, 3, 4, 6-tetra-O-acetyl-β-D-glucopyranosides (1) was deacetylated with NaOMe in MeOH lead to allyl-β-D-glucopyranoside (2) which was perallylated and followed by hydroboration and subsequent oxidation afforded (3-hydroxy-propyl) 2, 3, 4, 6-tetraO(3-hydroxy-propyl)- β-D-glucopyranoside (4). As a result, not only allylpropylene glycol β-D-glucopyranosides (5, 7, and 9) but also hydroxypropylene glycol β-D-glucopyranosides (6, 8, and 10) were synthesized by repeated sequential perallylation followed by hydroboration/oxidation. Keywords : hydroboration/oxidation, perallylation, oligo-hydroxypropylene glycol β-D-glucopyranosides 1. INTRODUCTION Carbohydrates are naturally occurring abund-ant compounds that have been widely studied for a plethora of applications (Hanessian, 1983; Scott, 1994; Middleton et al., 1993). Of parti-cular interest has been their use as polyfunctional molecules for the design and/or synthesis of car-bohydrate-centered multivalent glycoclusters and glycodendrimers (Lindhorst et al., 1998; Lind-horst et al., 2001; Lindhorst et al., 2006). Most of them are based on a multi-step synthesis con-sisting of oligo-glycosylation in order to achieve a uniform O-hydroxy-spacer, such as ethylene or propylene glycol not only in the 2, 3, 4, 6-tetra hydroxy groups but also at the α-anomeric po-sition, turning them into carbohydrate-centered cluster glycosides (Lindhorst et al., 1998; Lind-horst et al., 2001; Lindhorst et al., 2006).Thus, it became our goal to attempt the syn-thesis of the exhaustive glycosylation of octopus type β-D-glucopyranosides. This could provide us with a great potential opportunity of a novel class of high-molecular weight monosaccharide mimetics, which could possibly be adapted for the generation of various spacers with different |
