- Iron(iii) chloride modulated selective 1,2-trans glycosylation based on glycosyl trichloroacetimidate donors and its application in orthogonal glycosylation
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The development of a new glycosylation method for efficient stereoselective synthesis of β-gluco- and galactosides from their corresponding armed trichloroacetimidate donors mediated by 10 mole% of FeCl3 has been focused. FeCl3 has a
- Mukherjee, Mana Mohan,Basu, Nabamita,Ghosh, Rina
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p. 105589 - 105606
(2016/11/18)
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- Synthesis of blocked trisaccharide analogue related to the repeating unit of the o-antigen form e. Coli: 025
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Methyl 2-O-benzoyW, frO-benzylidene-O-a-D-glucopyranoside 1 was condensed with rhamnose-1-thio donor 2 in the presence of NIS/TMSOTf to yield the disaccharide methyl 2,3,4-tri-0-acetyl-0-α-L-rhamnopyranosyl-(l-3)-2-0- benzoyl-4,6-O-benzylidene-O-α-o-gluco
- Srivastava, Jayant,Khare, Anakshi,Khare, Naveen K.
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experimental part
p. 848 - 852
(2009/12/24)
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- Synthesis and nmr characterisation of methyl mono- and DI-0-α-L-rhamnopyranosyl-α-d-glucopyranosiduronic acids
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The synthesis and NMR characterisation of methyl mono- and di-O-α-L-rhamnopyranosyl-α-D-glucopyranosiduronic acids 1-6 are described. Two commercial starting products were used: methyl α-D-glucopyranoside 7 for the preparation of 1 and 2, and methyl (R)-4,6-O-benzylidene-α-D-glucopyranoside 8 for 3-6. Oxidation reaction of the hydroxymethyl group of glucose to a carboxylic acid group was performed by sodium hypochlorite 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO)-mediated procedure after the coupling reaction. Glycosylation was carried out using the trichloroacetimidate approach with trimethylsilyl trifluoromethanesulfonate (TMSOTf) as promoter, resulting in a completely stereoselective formation of the a glycosyl linkage.
- Battistelli, Chiara Laura,De Castro, Cristina,Iadonisi, Alfonso,Lanzetta, Rosa,Mangoni, Lorenzo,Parrilli, Michelangelo
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- Phenylselenoglycosides as novel, versatile glycosyl donors. Selective activation over thioglycosides
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Selective activation of phenylselenoglycosides over ethylthioglycosides with silver trifluoromethanesulfonate and anhydrous potassium gives an efficient synthesis of disaccharides from selenoglycoside donors and thioglycoside acceptors. Activation is quenched by addition of 1,1,3,3-tetramethylurea or collidine.
- Mehta,Pinto
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p. 4435 - 4438
(2007/10/02)
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- SYNTHESIS AND CONFORMATIONAL ANALYSIS OF METHYL 3-O-MALTOSIDE DERIVATIVES: A BRANCHED TRISACCHARIDE WITH THE CENTRAL GLUCOPYRANOSE RESIDUE IN THE 1C4 CONFORMATION
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The branched trisaccharide 4-O-α-D-glucopyranosyl-3-O-α-L-rhamnopyranosyl-β-D-glucopyranose is a model for a part of the lipopolysaccharide from Shigella flexneri serotype I,1a, which has the structure ->2)-α-L-Rha-(1->3)-α-tives, using silver triflate-promoted glycosylation reactions.Similarly, the model disaccharide glucosides methyl 3-O-α-L(and D)-rhamnopyranosyl-α-(and β)-D-glucosides have been synthesized.The acetylated derivatives of the trisaccharides have been converted into their glycosyl bromides (22 and 23) and glycosyl fluorides (24 and25), and the latter transformed into the 1,6-anhydro derivatives by treatment with srong acid base.The conformations of the acetylated derivatives have been analysed by 1H- and 13C-n.m.r. spectroscopy.In most of the branched trisaccharide derivatives, the conformation of the central glucopyranose residue is predominantly 1C4.X-Ray analysis showed that, in the solid state for the glycosyl fluoride 24, the conformation of the central glucopyranose residue is 1C4.
- Bock, Klaus,Guzman, Fernandez-Bolanos,Norrestam, Rolf
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