title: Efficient Synthesis of 4-Amino-4-deoxy-L-arabinose and Spacer-equipped 4-Amino-4-deoxy-L-arabinopyranosides by Transglycosylation Reactions.
abstract: Methyl 4-azido-4-deoxy-β-L-arabinopyranoside has been synthesized in five steps starting from methyl β-D-xylopyranoside in a multigram scale without chromatographic purification in 78% overall yield. The transformation relied on selective tosylation/nosylation at O-4 followed by acylation, S(N)2 displacement with sodium azide and subsequent deprotection. The methyl 4-azido-4-deoxy-arabinoside was then converted into allyl, propenyl, ω-bromohexyl and chlorethoxyethyl spacer glycosides by transglycosylation with the respective alcohols in good yields and fair anomeric selectivity. Reduction of the azido group and further transformations of the aglycon afforded ω-thiol-containing spacer derivatives. Coupling to maleimide-activated BSA provided a potent immunogen which was used to generate murine and rabbit polyclonal sera binding to LPS-core epitopes containing 4-amino-4-deoxy-arabinose residues.
authors.affiliation: Department of Chemistry, University of Natural Resources and Applied Life Sciences-Vienna, Muthgasse 18, A-1190 Vienna, Austria.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Müller
authors.forename: Markus
authors.initials: M
authors.lastname: Blaukopf
authors.forename: Andreas
authors.initials: A
authors.lastname: Hofinger
authors.forename: Alla
authors.initials: A
authors.lastname: Zamyatina
authors.forename: Helmut
authors.initials: H
authors.lastname: Brade
authors.forename: Paul
authors.initials: P
authors.lastname: Kosma