Synthesis and NMR and conformational studies of branched oligosaccharides. 1. Synthesis of branched oligosaccharides containing identical monosaccharide substituents at O2 and 03 of the α-L-rhamnopyranose residue

N. E. Nifant'ev, L. V. Backinowsky, 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-bis-O-gly-cosylated derivatives of α-L-rhamnopyranose the following oligosaccharides were synthesized.

α-L-Rhap-(l-2)
              \
              α-L-Rhap-OMe                (VIII)
              /
α-L Rhap-(l-3)


α-D-Manp-(l-2)
              \
              α-L-Rhap-OMe                (X)
              /
α-L-Manp-(l-3)

β-D-Glcp-(l-2)
              \
              α-L-Rhap-OMe                (XII)
              /
β-D-Glcp-(l-3) 

β-L-Fucp-(l-2)
              \
              α-L-Rhap-OMe                (XIV)
              /
β-L-Fucp-(l-3)

β-L-Fucp-(l-2)-α-L-Rhap-OMe                (XIX)

α-L-Rhap-(l-2)
              \
              α-L-Rhap(1-2)-α-L-Rhap-OMe   (XXIII)
              /
α-L-Rhap-(l-3)

α-L-Rhap-(l-2)-α-L-Rhap-(l-2)-α-L-Rhap-OMe  (XXVIII)

α-D-Manp-(l-2)-α-L-Rhap-OMe                (XXX)

α-D-Manp-(l-3)-α-L-Rhap-OMe                (XXXII)

β-L-Fucp-(l-3)-α-L-Rhap-OMe                (XXXIV)

For these compounds the ¹H and ¹³C NMR spectra were obtained and interpreted. Signals in spectra of oligosaccharides (VIII), (X), (XII), (XIV), (XXIII), and (XXVIII) were-assigned with the use of 2D correlation spectroscopy ¹H–¹H COSYRCT and ¹H–¹³C.

Russian Journal of Bioorganic Chemistry 1991, 17 (4):517-530

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