Concise synthesis of 1-deoxy-4-O-β-D-galactopyranosyl-D-nojirimycin avoiding a glycosylation step

Article abstract of DOI:10.1016/S0040-4039(00)02165-1

2′,6′-Di-O-benzyl-2,3:5,6:3′,4′-tri-O-isopropylide nelactose dimethyl acetal was used as starting material for the preparation of the until now unknown 4-O-β-D-galactopyranosyl-D-xylo-hexos-5-ulose derivatives 7-9, through selective C-5 oxidation of its partially deprotected derivatives 4-6. Hydrolysis of 7-9 with aq. CF₃COOH led to deprotected 1,5-dicarbonyl disaccharides 11-12, diastereoselectively transformed without purification into 1-deoxy-4-O-β-D-galactopyranosyl-D-nojirimycin derivatives in about 60% yield, through a double reductive amination reaction.