D-galacturonic acid derivatives as acceptors and donors in glycosylation reactions

Article abstract of DOI:10.1016/S0008-6215(92)84237-M

Jones oxidation of suitably protected allyl β-D-galactopyranosides and subsequent esterification were reinvestigated. Partial deprotection of the resulting D-galacturonic acid derivatives afforded compounds suitable for transformation into glycosyl acceptors. The synthesis of 2-, 3-, and 4-trityl ethers, relying on efficient differential protecting-group strategies, is described. Trityl-cyanoethylidene condensation of these trityl ethers, leading to the protected disaccharide units β-D-Gal pA-(1 → 2)-D-Gal pA and β-D-Gal pA-(1 → 3)-Gal pA with high stereoselectivity, is demonstrated. A β-D-Gal pA-(1 → 4)-D-GalpA disaccharide was also prepared.