- Improved synthesis and the crystal structure of methyl 4,6-dideoxy-4-(3-deoxy-L-glycero-tetronamido)-α-D-mannopyranoside, the methyl α-glycoside of the intracatenary repeating unit of the O-polysaccharide of Vibrio cholerae O:1
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The crude product of deamination of the commercially available L-homoserine was acetylated and the 2-O-acetyl-3-deoxy-L-glycero-tetronolactone (18) formed was used to N-acylate methyl perosaminide (methyl 4-amino-4,6-dideoxy-α-D-mannopyranoside, 12) and its 2,3-O-isopropylidene derivative.The major product isolated from the reaction was the crystalline methyl 4-(4-O-acetyl-3-deoxy-L-glycero-tetronamido)-4,6-dideoxy-α-D-mannopyranoside (1, 70-75percent) resulting from acetyl group migration in the initially formed 2'-O-acetyl derivative.O-Deacetylation of 1 gave the title amide 2.Compound 2, obtained crystalline for the first time, was fully characterized, and its crystal structure was determined.Deoxytetronamido derivatives diastereomeric with 1 and 2, respectively, were obtained by the acylation of 12 with 2-O-acetyl-3-deoxy-D-glycero-tetronolactone (prepared from D-homoserine), and subsequent deacetylation.Structures of several byproducts of the reaction of 12 with 18 have been deduced from their spectral characteristics.Since these byproducts were various O-acetyl derivatives of 2, the title compound could be obtained in ca. 90percent yield by deacetylating (Zemplen) the crude mixture of N-acylation products, followed by chromatography. Key words: α-D-Mannopyranoside, methyl 4,6-dideoxy-4-(3-deoxy-L-glycero-tetronamido-); O-Polysaccharide; Perosamine; Vibrio cholerae O:1
- Gotoh, Makoto,Barnes, Charles N.,Kovac, Pavol
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p. 203 - 218
(2007/10/02)
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- Synthesis of the Methyl α-D-Glycosides of Amicetose, Perosamine and Janose
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New methods for the synthesis of tri- and di-deoxy sugar, namely methyl α-D-amicetoside, methyl α-D-perosaminoside and methyl α-D-janoside are described.The readily available methyl 6-deoxy-2,3-O-isopropylidene-α-D-mannopyranoside has been used as chiral
- Kjoelberg, Ove,Neumann, Klaus
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p. 877 - 882
(2007/10/02)
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- SYNTHESIS OF ANTIGENIC DETERMINANTS OF THE Brucella A ANTIGEN, UTILIZING METHYL 4-AZIDO-4,6-DIDEOXY-α-D-MANNOPYRANOSIDE EFFICIENTLY DERIVED FROM D-MANNOSE
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A strategy for the synthesis of Brucella O-antigenic determinants containing 2-linked 4,6-dideoxy-4-formamido-α-D-mannopyranosyl residues is described.The approach adopted also permits the N-acyl moiety to be varied.A high-yield synthesis of methyl 4-azid
- Bundle, David R.,Gerken, Manfred,Peters, Thomas
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p. 239 - 252
(2007/10/02)
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- Synthesis and Nuclear Magnetic Resonance Studies of Some N-Acylated Methyl 4-Amino-4,6-dideoxy-α-D-mannopyranosides
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The methyl α-glycosides of 4-amino-4,6-dideoxy-D-mannopyranose (perosamine), N-acylated with either formic, acetic, or (S)-2,4-dihydroxybutanoic acid, have been synthesized.The (1)H and (13)C n.m.r. spectra of these substances and the parent, non-N-acylated glycoside, demonstrated how the chemical shifts are influenced by the N-acylation.The N-formyl derivative occured in two conformations, s-cis and s-trans, and the free-energy barrier between these, 86.9 kJ mol-1, was defined by dynamic n.m.r. spectroscopy.
- Kenne, Lennart,Unger, Per,Wehler, Thomas
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p. 1183 - 1186
(2007/10/02)
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