An expeditious preparation of various sulfoforms of the disaccharide β-d-Galp-(1 → 3)-d-Galp, a partial structure of the linkage region of proteoglycans, as their 4-methoxyphenyl β-d-glycosides Original Research Article

An expeditious preparation of various sulfoforms of the disaccharide 4-methoxyphenyl O-(β-d-galactopyranosyl)-(1 → 3)-β-d-galactopyranoside, namely the 4I- and 6I-sulfate, the 4II- and 6II-sulfate, and the 6I,6II-disulfate derivatives, is reported for the first time. These molecules will be useful for the study of the early steps of the biosynthesis and sorting of proteoglycans. All target compounds were readily obtained from the common key intermediate 4-methoxyphenyl O-(2,3-di-O-benzoyl-4,6-di-O-levulinoyl-β-d-galactopyranosyl)-(1 → 3)-2-O-benzoyl-4,6-O-benzylidene-β-d-galactopyranoside, easily prepared from the common starting material 4-methoxyphenyl 4,6-O-benzylidene-β-d-galactopyranoside. Noticeable is the possible preparation of the different 6-O-sulfonated species through a one-pot procedure starting from a tetrol precursor.