518975-23-0Relevant academic research and scientific papers
Synthesis of β-D-Glcp-(1→2)-[β-D-Ribf-(1→3)-]α-L-Rhap- (1→3)-α-L-Rhap-(1→2)-α-L-Rhap, the repeating unit of the lipopolysaccharide of Acetobacter diazotrophicus PAL 5
Zhang, Jianjun,Kong, Fanzuo
, p. 579 - 589 (2007/10/03)
A pentasaccharide, the major repeating unit of the lipopolysaccharide (LPS) of the nitrogen fixing bacterium Acetobacter diazotrophicus PAL 5 was efficiently synthesized as its allyl glycoside using a regio- and stereoselective strategy. The key acceptor, allyl 3-O-acetyl-4-O-benzoyl-α-L-rhamnopyranoside (3), was prepared by selective 3-O-acetylation of allyl 4-O-benzoyl-α-L-rhamnopyranoside. Condensation of 3 with 2,3,4,6-tetra-O-benzoyl-α-D-glucopyranosyl trichloroacetimidate furnished the disaccharide 5. Deallylation and subsequent trichloroacetimidation of 5 afforded 2,3,4,6-tetra-O-benzoyl-β-D-glucopyranosyl-(1→2)-3-O-acetyl-4-O- benzoyl-α-L-rhamnopyranosyl trichloroacetimidate (10). Selective 3-O-glycosylation of allyl α-L-rhamnopyranoside (1) with 10 followed by benzoylation gave trisaccharide (12), which could be conveniently converted to a donor (14). Condensation of 14 with allyl 3,4-di-O-benzoyl-α-L-rhamnopyranoside (15) gave tetrasaccharide 16. Selective deacetylation of 16 gave the acceptor 17 which was ribosylated to furnish the protected pentasaccharide, and finally deprotection led to the title compound.
