Solution- and solid-phase oligosaccharide synthesis using glucosyl iodides: a comparative study.
Glycosyl iodide donors have been used in both solid- and solution-phase syntheses yielding alpha-(1 --> 6)-linked glucosyl oligomers in highly efficient protocols. While the solid-phase strategy offers advantages in terms of ease of purification, it requires a total of 7.5 equiv of donor and approximately 12 h to complete the incorporation of one monosaccharide unit. In contrast, solution-phase methods require only 2.5 equiv of donor and 2-3 h reaction time per glycosylation. Moreover, since the reactions are virtually quantitative (> 90%) column chromatography of the material is facile. The overall advantages of solution-phase oligosaccharide synthesis were further illustrated in the convergent synthesis of a hexamer (methoxycarbonylmethyl 6-O-acetyl-2,3,4-tri-O-benzyl-alpha-D-glucopyranosyl-(1 --> 6)-tetrakis-(2,3,4-tri-O-benzyl-alpha-D-glucopyranosyl-(1 --> 6))-2,3,4-tri-O-benzyl-1-thio-alpha-D-glucopyranoside) that was constructed from dimer donor iodides in a two-plus-two and a two-plus-four fashion.
Lam
Son N
SN
University of California, Davis, Department of Chemistry, Davis, CA 95616, USA.
Gervay-Hague
Jacquelyn
J
D002236:Carbohydrate Conformation; D005960:Glucosides / Q000737:chemistry; D006031:Glycosylation; D007454:Iodides / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D009844:Oligosaccharides / Q000138:chemical synthesis*; D012996:Solutions; D013237:Stereoisomerism
D005960:Glucosides; D007454:Iodides; D009844:Oligosaccharides; D012996:Solutions