title: Stereoselective Synthesis of α- and β-l-Ara4N Glycosyl H-Phosphonates and a Neoglycoconjugate Comprising Glycosyl Phosphodiester Linked β-l-Ara4N.
abstract: Stereoselective synthesis of variably protected α- and β-l-Ara4N glycosyl H-phosphonates as key intermediates in the syntheses of β-l-Ara4N-modified LPS structures and α-l-Ara4N-containing biosynthetic precursors is reported. A facile one-pot approach toward β-l-Ara4N glycosyl H-phosphonates includes anomeric deallylation of protected 4-azido β-l-Ara4N via terminal olefin isomerization followed by ozonolysis and methanolysis of formyl groups to furnish exclusively β-configured lactols that are phosphitylated with retention of configuration. The carbohydrate epitope of β-l-Ara4N-modified Lipid A, βGlcN(1→6)αGlcN(1→P←1)β-l-Ara4N, was stereoselectively synthesized and linked to maleimide-activated bovine serum albumin.
authors.affiliation: Department of Chemistry, University of Natural Resources and Life Sciences , Muthgasse 18, A-1190 Vienna, Austria.
authors.forename: Ralph
authors.initials: R
authors.lastname: Hollaus
authors.affiliation: Department of Chemistry, University of Natural Resources and Life Sciences , Muthgasse 18, A-1190 Vienna, Austria.
authors.forename: Paul
authors.initials: P
authors.lastname: Kosma
authors.affiliation: Department of Chemistry, University of Natural Resources and Life Sciences , Muthgasse 18, A-1190 Vienna, Austria.
authors.forename: Alla
authors.identifier: 0000-0002-4001-3522
authors.initials: A
authors.lastname: Zamyatina