ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Preparation of methyl 6-o-beta-d-galactopyranosyl-alpha-galactopyranosides and 6-o-beta-d-galactopyranosides

J. Hlavatý, Š. Karácsonyi, and J. Alfőldi

Institute of Chemistry, Centre for Chemical Research, Slovak Academy of Sciences, CS-842 38 Bratislava

Abstract: By condensation of l,2:3,4-di-0-isopropylidene-α-D-galactose with 2,3,4,6-tetra-O-acetyl-α-D-galactopyranosyl bromide in acetonitrile in the presence of Hg(CN)₂ l,2:3,4-di-0-isopropylidene-6-O-(2,3,4,6-tetra-O-acetyl-β-D-galactopyranosyl)-α-D-galactopyranose has been prepared. This derivative on deacetylation and removal of the protecting groups afforded 6-O-β-D-galactopyranosyl-D-galactopyranose. Glycosidation of per-O-acetyl-6-0-β-D-galactobiose in acetonitrile in the presence of Hg(CN)₂ gave a mixture of methyl 2,3,4-tri-0-acetyl-6-0-(2,3,4,6-tetra-0-acetyl-β-D-galactopyranosyl)-β- and -α-D-galactopyranosides. When using Ag₂C0₃ and iodine in dichloromethane, only the ß-anomer was formed. After deacetylation methyl 6-0-ß-D-galactopyranosyl-ß-D-galactopyranoside and methyl 6-0-β-D-galactopyranosyl-α-D-galactopyranoside were obtained.

Full paper in Portable Document Format: 424a519.pdf

Chemical Papers 42 (4) 519–525 (1988)