34395-01-2Relevant academic research and scientific papers
Direct synthesis of 1,6-anhydro sugars from unprotected glycopyranoses by using 2-chloro-1,3-dimethylimidazolinium chloride
Tanaka, Tomonari,Huang, Wei Chun,Noguchi, Masato,Kobayashi, Atsushi,Shoda, Shin-ichiro
supporting information; experimental part, p. 2154 - 2157 (2009/08/17)
Various 1,6-anhydro sugars have been synthesized directly from the corresponding unprotected glycopyranoses in excellent yields by using 2-chloro-1,3-dimethylimidazolinium chloride (DMC) as a dehydrative condensing agent. The reactions took place smoothly under mild reaction conditions in aqueous media. The present method would be a practical tool for synthesis of 1,6-anhydro derivatives of monosaccharides, linear-oligosaccharides, and branched-oligosaccharides.
EFFECT OF PROTECTING GROUPS AND SOLVENTS IN ANOMERIC O-ALKYLATION OF MANNOPYRANOSE
Tamura, Junichi,Schmidt, R. R.
, p. 895 - 912 (2007/10/02)
Anomeric O-alkylation of mannopyranoses with various protecting groups was investigated using mannose derivatives and 2,3-O-isopropylidene-1-O-trifluoromethanesulfonyl-D-glycerol (1) as alkylating agent.Generally, in polar solvents higher α/β ratios were obtained than in nonpolar solvents.Sterically demanding protecting groups at the 6-O-position and polar solvents led to higher yields.Reactivity differences were explained by different complex formation.Based on these results mannopyranosyl-α(1-4)glucopyranosides 26 and 27 were synthesized using mannose derivatives 5 and 6 having a 6-O-(p-methoxyphenyl)diphenylmethyl group and galactosyl trifluoromethanesulfonate 24 or nonafluorobutanesulfonate (nonaflate) 25, respectively, as alkylating agents.
Anomeric O-Alkylation, 9. Disaccharide Synthesis via Anomeric O-Alkylation
Tsvetkov, Yury E.,Klotz, Wolfgang,Schmidt, Richard R.
, p. 371 - 376 (2007/10/02)
Base-promoted reaction of tetra-O-benzyl-glucose 1a with secondary alkyl trifluoromethanesulfonates 2 and 3 in toluene provides in the presence of 15-crown-5 preferentially β-glycosides 2aβ and 3aβ, respectively, in high yields.For reactions carried out a
The function of the 5-hydroxymethyl group of lactose in enzymatic hydrolysis with beta-galactosidase from E. coli.
Adelhorst,Bock
, p. 1114 - 1121 (2007/10/02)
A series of 6-substituted methyl lactoside derivatives together with methyl allolactoside and (6S)-methyl [6-2H]lactoside have been synthesized and characterized by NMR spectroscopy. All compounds were tested as substrates for the enzyme beta-galactosidas
Synthesis and characterization of 6-O-β-lactosyl-α,β-lactoses, 1-O-(6-O-β-lactosyl-β-lactosyl)-(R,S)-glycerols, and 4,6-di-O-β-D-galactopyranosyl-α,β-D-glucoses
Hronowski,Szarek,Hay,Krebs,Depew
, p. 101 - 117 (2007/10/02)
1,2,3,2',3',4',6'-Hepta-O-acetyl-β-lactose (4) was coupled with 2,3,6,2',3',4',6'-hepta-O-acetyl-α-lactosyl bromide (7) in the presence of Hg(CN)2 to afford 1,2,3,2',3',4',6'-hepta-O-acetyl-6-O-(2,3,6,2',3',4',6'-hepta-O- acetyl-β-lactosyl)-β-lactose (11) which, upon O-deacetylation, gave 6-O-β-lactosyl-α,β-lactoses (64% from 4). In contrast, the reaction of 7 with benzyl 2,3,2',3',4',6'-hexa-O-acetyl-β-lactoside in the presence of Hg(CN)2 produced 3,6,2',3',4',6'-hexa-O-acetyl-1,2-O-(2,3,2',3',4',6'-hexa-O-acetyl-1- O-benzyl-β-lactos-6-yl orthoacetyl)-α-lactose (63%) and 3,6,2',3',4',6'-hexa-O-acetyl-1,2-O-(1-cyanoethylidene)-α-lactose (27%). The glycosidation of 4 using 2,3,4,6-tetra-O-acetyl-α-D-galactopyranosyl bromide in the presence of Hg(CN)2 afforded, after deprotection, 4,6-di-O-β-D-galactopyranosyl-α,β-D-glucoses (66%). The reaction of 11 with 1,2-di-O-benzyl-(R,S)-glycerols and trimethylsilyl trifluoromethanesulfonate yielded, after deprotection, 1-O-(6-O-β-lactosyl-β-lactosyl)-(R,S)-glycerols (18%). Under the same coupling conditions 11 reacted with 2-O-benzylglycerol to form 3-O-acetyl-2-O-benzyl-1-O-{2',3',4',6'-hexa-O-acetyl-6-O-(2,3,6,2',3' ,4',6'-hepta-O-acetyl-β-lactosyl)-β-lactosyl}-(R,S)-glycerols (16%). 1,2,3,2′,3′,4′,6′-Hepta-O-acetyl-β-lactose (4) was coupled with 2,3,6,2′,3′,4′,6′-hepta-O-Acetyl-α- lactosyl bromide (7) in the presence of Hg(CN)2 to afford 1,2,3,2′,3′,4′,6′-hepta-O-acetyl-6-O-(2,3,6,2′,3$ PRM, 4′,6′-hepta-O-acetyl-6-O-(2,3,6,2′,3′, 4′,-hepta-O-acetyl-β-lactosyl)-β-lactose (11) which, upon O-deacetylation, gave 6-O-β-lactosyl-α,β-lactoses (64% from 4). In contrast, the reaction of 7 with benzyl 2,3,2′,3′,4′,6′-hexa-O-acetyl-β-lactoside in the presence of Hg(CN)2 produced 3,6,2′,3′,4′,6′-hexa-O- acetyl-1,2-O-(2,3,2′,3′,4′,6′-hexa-O-acetyl-1-O-benzy l- β-lactos-6-yl orthoacctyl)-α-lactose (63%) and 3,6,2′,3′,4′,6′-hexa- O-acetyl-1,2-O-(1-cyanoethylidene)-α-lactose (27%). The glycosidation of 4 using 2,3,4,6-tetra-O-acetyl-α-D- galactoyranosyl bromide in the presence of Hg(CN)2 afforded, after deprotection, 4,6-di-O-β-D- galactopyranosyl-α,β-D-glucoses (66%). The reaction of 11 with 1,2-di-O-benzyl-(R,S)-glycerols and trimethylsilyl trifluoromethanesulfonate yielded, after deprotection, 1-O-(6-O-β-lactosyl-β-lactosyl)-(R,S)-glycerols (18%). Under the same coupling conditions II reacted with 2-O-benzylglycerol to form 3-O-acetyl-2-O-benzyl- O-{2′,3′,4′,6′-hexa-O-acetyl-6-O-(2,3,6,2′,3 ′, 4′,6′-hepta-O-acetyl-β-lactosyl)-β-lactosyl}-( R,S)- glycerols (16%).
TOTAL SYNTHESIS OF CYCLOMALTOHEXAOSE
Takahashi, Yukio,Ogawa, Tomoya
, p. 277 - 296 (2007/10/02)
Described for the first time is a total synthesis of cyclomaltohexaose, in 0.3percent overall yield, in 21 steps starting from maltose.Maltose was transformed into allyl O-(2,3,6-tri-O-benzyl-α-D-glucopyranosyl)-(1->4)-2,3,6-tri-O-benzyl-β-D-glucopyranosi
STUDIES ON SIALIC ACIDS. V. SYNTHESIS OF α- AND β-D-Neu5Acp-(2->6)-LACTOSE
Furuhata, Kimio,Anazawa, Katsuko,Itoh, Masayoshi,Shitori, Yoshiyasu,Ogura, Haruo
, p. 2725 - 2731 (2007/10/02)
The reaction of methyl 5-acetamide-4,7,8,9-tetra-O-acetyl-2-chloro-2,3,5-trideoxy-D-glycero-β-Dgalacto-2-nonulopyranosonate with 1,6-anhydro-2,2',3,3',4'-penta-O-benzyl-β-D-lactose in the presence of mercury cyanide and mercury bromide gave a 1:1 mixture
