Synthesis of Methyl (Ethyl 2-O-acyl-3,4-di-O-benzyl-1-thio-.beta.-D-glucopyranosid)uronates and Evaluation of Their Use as Reactive .beta.-Selective Glucuronic Acid Donors
作者:Per J. Garegg、Lars Olsson、Stefan Oscarson
DOI:10.1021/jo00112a046
日期:1995.4
The synthesis of derivatives of methyl (ethyl 2-0-acyl-3,4-di-O-benzyl-1-thio-beta-D-glucopyranosid)-uronate with different ester groups (acetyl, benzoyl, pivaloyl, and anisoyl) at O-2 is described. The synthesis proceeds via a two-step oxidation (DMSO/DCC followed by PDC/MeOH) of C-6 on a suitably protected glucose derivative to give directly the methyl glucuronic ester without affecting the thioglycoside. The thioglucuronides were tested as donors in coupling reactions with unreactive carbohydrate alcohols using dimethyl(methylthio)sulfonium triflate (DMTST) as promoter, Due to the activating benzyl protecting groups at O-3 and -4, the sluggishness of fully acylated glucuronic acid donors could be overcome and glucuronide disaccharides were produced in fair to good yields. The glucuronides were obtained with the desired P-configuration because of the participating group at O-2. Among the different ester groups tried, the benzoyl group was found to give the highest yield in the couplings.
Kucar, Stefan; Zamocky, Juraj; Zemek, Juraj, Collection of Czechoslovak Chemical Communications, 1984, vol. 49, # 8, p. 1780 - 1787
作者:Kucar, Stefan、Zamocky, Juraj、Zemek, Juraj、Anderle, Dusan、Matulova, Maria
DOI:——
日期:——
Synthesis of the Repeating Unit of the Capsular Polysaccharide of Streptococcus Pneumoniae Type 3 as a Building Block Suitable for Formation of Oligomers
作者:Per. Garegg、Stefan Oscarson、Ulf Tedebark
DOI:10.1080/07328309808002339
日期:1998.5.1
The synthesis of a cellobiouronic thioglycoside donor 12, protected with a selectively removable 3′-O-benzyl group is described. The donor 12 is suitable as a monomer building block in the construction of oligomer structures corresponding to the capsularpolysaccharide of Streptococcus pneumoniaetype 3. The carboxyl function was introduced through regioselective TEMPO-oxidation of a 4′,6′-diol cellobiose