352020-79-2Relevant academic research and scientific papers
Synthesis of 1-deoxyhept-2-ulosyl-glycono-1,5-lactone utilizing α-selective O-glycosidation of 2,6-anhydro-1-deoxy-d-hept-1-enitols
Namme, Rie,Mitsugi, Takashi,Takahashi, Hideyo,Shiro, Moto,Ikegami, Shiro
, p. 9183 - 9192 (2007/10/03)
A series of 1-deoxy-heptulo-2-pyranosyl-glycono-1,5-lactones were synthesized utilizing completely α-selective O-glycosidation of heptenitols. Anomeric configuration of the products was confirmed by 3JC,H coupling measurement and X-ray crystal structural analysis. The benzyl-protected ketosyl saccharides were partly unstable, and glycosidic linkage was prone to cleave under the usual debenzylation conditions. To prevent this, we surveyed various additives for the Pd-catalyzed hydrogenation reaction and found that basic alumina was the most effective.
An efficient synthesis of new 1′-C-methyl-α-O-disaccharides using 1-methylenesugars as the glycosyl donors
Li, Xiaoliu,Ohtake, Hiro,Takahashi, Hideyo,Ikegami, Shiro
, p. 4283 - 4295 (2007/10/03)
A series of new 1′-C-methyl-α-disaccharides were firstly synthesized by the directly Lewis acid-catalyzed O-glycosidation of 1-methylenesugars used as glycosyl donors. The O-glycosidation afforded stereospecifically the corresponding 1′-methyl-α-O-glycosides whose configurations were tentatively assigned by the NMR spectra, COSY and the C-H coupling constant 3JH-2′,Me-1′. The O-glycosidation of the acetyl protected 1-methylenesugars showed that the acetyl group at the C-2-O position was not effective to control the stereochemistry of the product by neighboring group participation because of the formation of a tertiary oxycarbenium ion as a stable intermediate.
A facile synthesis of 1′-C-alkyl-α-disaccharides from 1-C-alkyl-hexopyranoses and methyl 1-C-methyl-hexopyranosides
Li, Xiaoliu,Ohtake, Hiro,Takahashi, Hideyo,Ikegami, Shiro
, p. 4297 - 4309 (2007/10/03)
Direct O-glycosidations using the 1-C-alkyl-2,3,4,6-tetra-O-benzyl-hexopyranoses as the glycosyl donors were carried out with a catalytic amount (0.2 equiv.) of trimethylsilyl trifluoromethanesulfonate (TMSOTf). The glycosidations proceeded α-stereoselect
