Synthesis of a pentasaccharide fragment of varianose, a cell wall polysaccharide from Penicillium varians.
The first synthesis of an oligosaccharide fragment of varianose, a polysaccharide produced by Penicillium varians, is reported. The target pentasaccharide features both alpha- and beta-galactofuranoside residues and the alpha-galactofuranoside residue is hindered, being substituted on adjacent oxygens (O1 and O2), both of which are cis to the two-carbon side chain at C4. Key features of the synthesis include a novel method for the selective protection of the C3 hydroxyl group of galactofuranosyl residues via an epoxide formation/opening sequence, the introduction of the alpha-d-galactofuranosyl residue using a 2,3-anhydrosugar donor, and the use of the 1-benzenesulfinylpiperidine/trifluoromethanesulfonic anhydride activation method for the addition of an alpha-D-glucopyranosyl residue to a hindered hydroxyl group in an advanced tetrasaccharide intermediate.
Bai
Yu
Y
Alberta Ingenuity Centre for Carbohydrate Science and Department of Chemistry, The University of Alberta, Gunning-Lemieux Chemistry Centre, Edmonton, Alberta T6G 2G2, Canada.
Lowary
Todd L
TL
D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002473:Cell Wall / Q000737:chemistry*; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000138:chemical synthesis* / Q000737:chemistry*; D010407:Penicillium / Q000737:chemistry*; D011135:Polysaccharides, Bacterial / Q000737:chemistry*
D009844:Oligosaccharides; D011135:Polysaccharides, Bacterial; C517328:varianose