Synthesis of Glycosides with 4-(4-Hydroxyphenyl)-1,2,3-thia- and -selenadiazole Aglycones

Glycosylation of 4-(4-hydroxyphenyl)-1,2,3-thia(selena)diazoles with 1-α-bromo-2,3,4,6-tetra-O-acetyl-D-glucopyranose, 1-α-bromo-2,3,4,6-tetra-O-acetyl-D-galactopyranose, and 1-α-bromo-2,3,5-tri-O-acetyl-D-xylopyranose under the conditions of interphase catalysis has afforded the corresponding acetylated glycosides. An alternative pathway of selenadiasole glycosides synthesis from semicarbazones of 1-β-O-(4-acetylphenyl)-2,3,4,6-tetra-O-acetyl-D-glucopyranose, -2,3,4,6-tetra-O-acetyl-D-galactopyranose, and -2,3,5-tri-O-acetyl-D-xylopyranose via oxidation with selenium dioxide has been elaborated.