116786-66-4Relevant articles and documents
Synthesis and Nuclear Magnetic Resonance Studies of Some N-Acylated Methyl 4-Amino-4,6-dideoxy-α-D-mannopyranosides
Kenne, Lennart,Unger, Per,Wehler, Thomas
, p. 1183 - 1186 (1988)
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.
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
Gotoh, Makoto,Barnes, Charles N.,Kovac, Pavol
, p. 203 - 218 (1994)
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