165199-13-3Relevant academic research and scientific papers
On the stereochemistry of tethered intermediates in p-methoxybenzyl- assisted β-mannosylation
Lergenmueller, Matthias,Nukada, Tomoo,Kuramochi, Koji,Dan, Akihito,Ogawa, Tomoya,Ito, Yukishige
, p. 1367 - 1376 (2007/10/03)
We have previously developed a novel method for the stereocontrolled synthesis of β-manno-glycoside. Starting from 2-O-PMB (p-methoxybenzyl)- protected mannosyl donor 1, conversion into the mixed acetal 3 under oxidative conditions followed by the activation of the anomeric position affords β-manno-glycoside as a single stereoisomer. Although the utility of this method has been further demonstrated in the synthesis of the core structure of Asn-linked glycan chains, there remained uncertainty with respect to the stereochemistry of the mixed acetal. In order to make a stereochemical assignment of this intermediate, diastereomeric acetals 14a, 15a and 14b, 15b were prepared from 9 + 10/7 and 11 + 12/13, respectively. Investigations by means of NMR and a computational approach using DADAS 90 for quantifying steric hindrance, resulted in the conclusion that 14a/15a derived from 2-O-PMB-protected 9 has an (S) configuration and 14b/15b derived from 2-O-unprotected 11 has an (R) configuration. Based on the characteristic 1H-NMR patterns inherent to the (S) isomers 4,6-O-benzylidene-protected 30- 35, derived from thiomannosides 5, 23, 24, 26, 27, were also revealed to have the (S) configuration.
p-Methoxybenzylidene-tethered β-mannosylation for stereoselective synthesis of asparagine-linked glycan chains
Dan, Akihito,Lergenmu?ller, Matthias,Amano, Masayuki,Nakahara, Yoshiaki,Ogawa, Tomoya,Ito, Yukishige
, p. 2182 - 2190 (2007/10/03)
One of the main obstacles in the chemical synthesis of Asn-linked glycoprotein oligosaccharides has been the formation of β-manno glycoside linked to the 4 position of N-acetylglucosamine. Addressing this fundamental problem, we previously developed the u
