SELECTIVE O-GLUCOSYLATION OF 4,7-DIHYDROXYCOUMARIN

Selective glucosylation of 4,7-dihydroxycoumarin 1 has been studied. D ifferent acidity of 4- and 7-hydroxyl functions provides the correspon ding synthetic paths. Interaction of 4,7-hydroxycoumarin monosodium sa lt with 2,3,4,6-tetra-O-acetyl-alpha-D-glucopyranosyl bromide 2 in DMF A followed by the product deacetylation provides 4-O-(beta-D-glucopyra nosyl)-7-hydroxycoumarin 3. Interaction of 4-benzyloxy-7-hydroxycoumar in 4 with 2 followed by the product deacetylation and debenzylation pr ovides 7-O-(beta-D-glucopyranosyl)-4-hydroxycoumarin 5.