Synthesis of tri- and tetra-saccharide derivatives related to Klebsiella type 57

252-25

Synthesis of a tetrasaccharide analogue related to the repeating unit of the antigen from Klebsiella type 2

434-43

Synthesis of a mannotetraose derivative related to the antigen from Escherichia coli O9a:K26:H–

308-31

Synthesis of <i>p-</i>tolyl<i> </i>3,4-<i>O</i>-isopropylidene-2-<i>O</i>-(methylthiomethyl)-β-<img src='http://www.niscair.res.in/jinfo/smaller.gif' border=0>-fucopyranose

639-641Treatment of p-tolyl 3,4-O-isopropylidene-6-deoxy-1-thio-β--galactopyranoside and related compounds with methyl sulfoxide in the presence of acetic anhydride afford the formation of a methylthiomethyl ether namely p-tolyl 3,4-O-isopropylidene-2-O-(methylthiomethyl)-β--fucopyranose in place of the expected 2-keto compound

Synthesis of some blocked di-and trisaccharide derivatives related to the repeating unit of the O-antigen from <i>Shigella dysenteriae </i>type 3 in the form of their glycosides

2386-2394Starling from D-galactose and D-galactosaminc hydrochloridc, two new monosaccharide synthons namely 2-(trimethylsilyl)ethyl 4-O-acctyl-2,6-di-O-benzyl-β-D-galactopyranoside 2 and phenyl 3-O-acetyl-4,6-O-benzylidene-2-deoxy-2-phthalimido-1-thio-β-D galactopyranoside 5 have been synthesized which are then allowed to react with the monosaccharide derivatives 3,9, 16, 22 and 24 in the presence of either NIS/TfOH or TESOTf to give two di- and two trisaccharide derivatives related to the repeating unit of Shigella dysenteriae type 3, in the form of their glycosides. These blocked oligosaccharides can be utilized for the synthesis of glycoconjugates as synthetic vaccines

Synthesis of some of partially methylated galactoses from 1,6-anhydrogalactose

361-363Starting from 1<span style="font-size:13.5pt;mso-bidi-font-size:6.5pt;font-family:HiddenHorzOCR; mso-bidi-font-family:HiddenHorzOCR">,6-anhydro-<span style="font-size: 13.5pt;mso-bidi-font-size:6.5pt;mso-fareast-font-family:HiddenHorzOCR">β<span style="font-size:13.5pt;mso-bidi-font-size:6.5pt;font-family:HiddenHorzOCR; mso-bidi-font-family:HiddenHorzOCR">-D-galactopyranose <b style="mso-bidi-font-weight: normal">1, 2,3-di-O-methyl- D-galactose 5, 2-<i style="mso-bidi-font-style: normal">O-methyl-D-galactose 10, 3-<i style="mso-bidi-font-style: normal"> O -melhyl-D-galactose 11 and 3,4-di-O-melhyl-D-galactose 1<b style="mso-bidi-font-weight: normal"><span style="font-size:15.0pt;mso-bidi-font-size:8.0pt;font-family: Arial">2<span style="font-size:15.0pt;mso-bidi-font-size:8.0pt; font-family:Arial"> <span style="font-size:16.0pt;mso-bidi-font-size: 9.0pt">have been synthesized. All of them have been characterised as their alditol acetates.</span

Synthesis of (<i>R</i>)-4,6-<i>O</i>-pyruvated trisaccharide related to the repeating unit of the antigen from <i style="">Shigella dysenteriae </i>type 9 in the form of its 2-(trimethylsilyl)ethyl glycoside

137-140Starting from D-galactose, and D-mannose a trisaccharide namely 2-(trimethylsilyl)ethyl-2,3-di-O-benzoyl-4,6-O-[(R)-1-methoxycarbonylethylidene]--D-galactopyranosyl-(1→4)-2, 3, 6-tri-O-benzyl-b-d-mannopyranosyl-(1→4)-2,6-di-O-ben­zyl-3-O-(4-methoxybenzyl)--D-galactopyranoside has been synthesized. Deprotection of the blocking functionality affords a deblocked trisaccharide, 2-(trimethylsilyl)ethyl-4,6-O-[(R)-1-methoxycarbonylethylidene]--D-galactopyranosyl-(1→4)--D-mannopyranosyl-(1→4)--D-galactopyranoside which is a part of the repeating unit of the O-antigen from Shigella dysenteriae type 9

Synthesis of tetrasaccharide related to the repeating unit of the <i>O</i>-antigen from <i>Shigella boydii </i>type 5 in the form of its <i>tert</i>-butyl ester and 2-(trimethylsilyl)ethyl glycoside

130-136Starting from D-mannose, D-glucose and L-rhamnose, two disaccharide blocks ethyl 2,3,4-tri-O-benzyl- -L-rhamnopyranosyl-(1→3)-2-O-benzyl-4,6-O-benzylidene-1-thio--D-mannopyranoside and tert-butyl 2-O-benzyl-4,6-O-benzylidene--D-mannopyranosyl-(1→4)-[2-(trimethylsilyl)ethyl 2,3-di-O-benzyl--D-glucopyranosid]uronate have been synthesized. Schmidt’s inverse addition technique of trichloroacetimidate is utilized for the construction of a disaccharide with a -mannosidic linkage in good yield. Coupling of this two disaccharides give the desired tetrasaccharide derivative, tert-butyl 2,3,4-tri-O-benzyl- -L-rhamnopyranosyl-(1→3)-2-O-benzyl-4,6-O-benzylidene--D-mannopyranosyl-(1→3)-2-O-benzyl-4,6-O-benzylidene--D-mannopyranosyl-(1→4)-[2-(trimethylsilyl)ethyl 2,3-di-O-benzyl--D-glucopyranosid]­uronate, which is related to the repeating unit of Shigella boydii type 5. The tetrasaccharide can be coupled with a suitable protein for the preparation of a synthetic vaccine

Revised synthesis of the pentasaccharide related to the repeating unit of the O-antigen from <i style="">Shigella dysenteriae</i> type-4 in the form of its methyl ester 2-(trimethylsilyl)ethyl glycoside

1058-1063A revised and simplified method has been developed for the synthesis of the pentasaccharide, related to the repeating unit of the O-antigen from Shigella dysenteriae type-4. The disaccharide donor 10 and the trisaccharide acceptor 8 with two hydroxyl groups are first synthesized which are then allowed to react in the presence on NIS and TfOH to give a pentasaccharide derivative from which, removal of protecting groups affords the desired repeating unit, namely methyl -L-fucopyranosyl-(1→3)-2-acetamido-2-deoxy--D-glucopyranosyl-(1→3)-2-acetamido-2-deoxy-4-O-( -L-fucopyranosyl)- -D-glucopyranosyl-(1→4)-[2-(trimethylsilyl)ethyl -D-glucopyranosid] uronate 15