Synthesis, NMR and conformational studies of branched oligosaccharides. 3. Synthesis of 2,3-di-O-glycosylated methyl α-L-rhamnopyranoside derivatives
N. E. Nifant'ev, G. M. Lipkind, A. S. Shashkov, N. K. Kochetkov
N. D. Zelinsky Institute of Organic Chemistry, Academy of Sciences of the USSR, Moscow
Abstract: Within a programme of spectral (NMR) and conformational studies of 2,3-di-O-glyco-sylated derivatives of α-L-rhamnopyranose, a series of branched oligosaccharides (I)–(XII) was synthesized.
X-(1-2) \ α-L-Rhap-OMe (I) - (XII) / Y-(1-3) X Y -------------------- (I) α-D-Manp α-L-Rhap (II) α-D-Manp β-D-Glcp (III) α-D-Manp β-L-Fucp (IV) β-D-Glcp α-D-Manp (V) β-D-Glcp α-D-Manp (VI) β-D-Glcp β-L-Fucp (VII) α-L-Fucp β-L-Fucp (VIII) α-L-Fucp α-D-Manp (IX) α-L-Fucp β-D-Glcp (X) β-L-Fucp α-L-Rhap (XI) β-L-Fucp α-D-Manp (XII) β-L-Fucp β-D-Glcp
The preparation was carried out using stereoselective glycosylation of (1→3)-linked disaccharidic glycosyl-acceptors and appropriately substituted methyl 2-O-(β-L-fu-copyranosyl)-α-L-rhamnopyranoside. In the synthesis of compounds (VII)–(IX) the α-L-fucopyranosyl residue was stereoselectively introduced using benzobromofucose and per-O-acetylated 1-thiofucoside.
Russian Journal of Bioorganic Chemistry 1991, 17 (9):1229-1250