title: Pyranoside-into-furanoside rearrangement: new reaction in carbohydrate chemistry and its application in oligosaccharide synthesis.
abstract: Great interest in natural furanoside-containing compounds has challenged the development of preparative methods for their synthesis. Herein a novel reaction in carbohydrate chemistry, namely a pyranoside-into-furanoside (PIF) rearrangement permitting the transformation of selectively O-substituted pyranosides into the corresponding furanosides is reported. The discovered process includes acid-promoted sulfation accompanied by rearrangement of the pyranoside ring into a furanoside ring followed by solvolytic O-desulfation. This process, which has no analogy in organic chemistry, was shown to be a very useful tool for the synthesis of furanoside-containing complex oligosaccharides, which was demonstrated by synthesizing disaccharide derivatives α-D-Galp-(1→3)-β-D-Galf-OPr, 3-O-s-lactyl-β-D-Galf-(1→3)-β-D-Glcp-OPr, and α-L-Fucf-(1→4)-β-D-GlcpA-OPr related to polysaccharides from the bacteria Klebsiella pneumoniae and Enterococcus faecalis and the brown seaweed Chordaria flagelliformis.
authors.affiliation: Laboratory of Glycoconjugate Chemistry, N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky prospect 47, 119991 Moscow (Russian Federation).
authors.forename: Vadim B
authors.initials: VB
authors.lastname: Krylov
authors.forename: Dmitry A
authors.initials: DA
authors.lastname: Argunov
authors.forename: Dmitry Z
authors.initials: DZ
authors.lastname: Vinnitskiy
authors.forename: Stella A
authors.initials: SA
authors.lastname: Verkhnyatskaya
authors.forename: Alexey G
authors.initials: AG
authors.lastname: Gerbst
authors.forename: Nadezhda E
authors.initials: NE
authors.lastname: Ustyuzhanina
authors.forename: Andrey S
authors.initials: AS
authors.lastname: Dmitrenok
authors.forename: Johannes
authors.initials: J
authors.lastname: Huebner
authors.forename: Otto
authors.initials: O
authors.lastname: Holst
authors.forename: Hans-Christian
authors.initials: HC
authors.lastname: Siebert
authors.forename: Nikolay E
authors.initials: NE
authors.lastname: Nifantiev
mesh_terms: D002240:Carbohydrate Sequence; D013293:Enterococcus faecalis / Q000737:chemistry; D006027:Glycosides / Q000138:chemical synthesis / Q000737:chemistry*; D006031:Glycosylation; D007711:Klebsiella pneumoniae / Q000737:chemistry; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000138:chemical synthesis* / Q000737:chemistry; D012624:Seaweed / Q000737:chemistry
chemical_list: D006027:Glycosides; D009844:Oligosaccharides
keywords: carbohydrates; furanoside; glycosylation; rearrangement; sulfation