224622-39-3Relevant academic research and scientific papers
Synthesis of an L-rhamnose tetrasaccharide, the common and major structure of the repeating unit of the O-antigenic polysaccharide of a strain of Klebsiella pneumoniae and Pseudomonas holci
Zhang, Jianjun,Zhu, Yuliang,Kong, Fanzuo
, p. 229 - 235 (2007/10/03)
A tetrasaccharide, α-L-Rhap-(1 → 3)-α-L-Rhap-(1 → 2)-α-L-Rhap-(1 → 2)-L-Rhap, the common and major structure of the repeating unit of the O-antigenic polysaccharide of a strain of Klebsiella pneumoniae and Pseudomonas holci was synthesized as its methyl and octyl glycosides. Selective 3-O-glycosylation of allyl α-L-rhamnopyranoside with 2,3,4-tri-O-acetyl-α-L-rhamnopyranosyl trichloroacetimidate gave allyl 2,3,4-tri-O-acetyl-α-L-rhamnopyranosyl-(1 → 3)-α-L-rhamnopyranoside (3). Benzoylation, deallylation, and trichloroacetimidation afforded 2,3,4-tri-O-acetyl-α-L-rhamnopyranosyl-(1 → 3)-2,4-di-O-benzoyl-α-L-rhamnopyranosyl trichloroacetimidate (6). Self condensation of 3,4-di-O-benzoyl-β-L-rhamnopyranose 1,2-methyl orthoester or 1,2-octyl orthoester gave methyl or octyl 2-O-acetyl-3,4-di-O-benzoyl-α-L-rhamnopyranosyl-(1 → 2)-3,4-di-O-benzoyl-α-L-rhamnopyranoside (16 or 17), and subsequent selective deacetylation gave the disaccharide acceptor (18 or 19). Coupling of 6 with 18 (or 19), followed by deacylation in ammonia-saturated methanol, produced the target tetrasacharide.
A highly efficient and convergent synthesis of a hexasaccharide, a dimer of the repeating unit of the antigen O2 polysaccharide of Stenotrophomonas maltophilia
Wang, Wei,Kong, Fanzuo
, p. 128 - 136 (2007/10/03)
A highly efficient and convergent synthesis of a hexasaccharide, which is a dimer of the repeating unit of the antigen O2 polysaccharide of Stenotrophomonas maltophilia, was achieved via coupling of 2,3,4-tri-O-acetyl-α-L-xylopyranosyl bromide with the tetrasaccharide, allyl 4-O-{3-O-[4-O-(3,4-di-O-benzoyl-α-L-rhamnopyranosyl)-2,3,6-tri-O-benzoyl-α-D-mannopyranosyl]-4-benzoyl-α-L-rhamnopyranosyl}-2,3,6-tri-O-benzoyl-α-D-mannopyranoside (18) by the Koenigs-Knorr method followed by deacylation. Compound 18 was readily prepared from the coupling of the disaccharide trichloroacetimidate, 4-O-(2-O-acetyl-3,4-di-O-benzoyl-α-L-rhamnopyranosyl)-2,3,6-tri-O-benzoyl-α-D-mannopyranosyl trichloroacetimidate (8) with the disaccharide acceptor, allyl 4-O-(2-O-acetyl-4-O-benzoyl-α-L-rhamnopyranosyl)-2,3,6-tri-O-benzoyl-α-D-mannopyranoside (16), and both 8 and 16 were prepared via the trichloroacetimidate method from simple starting materials. The sole use of acyl protecting groups substantially simplified protection and deprotection, and the allyl group at the reducing end of allyl 4-O-{2-O-[2,3,4-tri-O-acetyl-β-L-xylopyranosyl]-3-O-[4-O-(2-O-(2,3,4-tri-O-acetyl-β-L-xylopyranosyl)-3,4-di-O-benzoyl-α-L-rhamnopyranosyl)-2,3,6-tri-O-benzoyl-α-D-mannopyranosyl]-4-O-benzoyl-α-L-rhamnopyranosyl}-2,3,6-tri-O-benzoyl-α-D-mannopyranoside 19 allowed further chemical transformation. Copyright (C) 1999 Elsevier Science Ltd.
Facile synthesis of a branched trisaccharide - The repeating unit of antigen O2 polymer using orthoester formation - rearrangement strategy
Wang, Wei,Kong, Fanzuo
, p. 263 - 273 (2007/10/03)
The synthesis of a branched trisaccharide, the repeating unit of the antigen O2 polymer containing L-rhamnose, D-mannose, and L-xylose, was achieved using orthoester formation - rearrangement strategy.
