title: Rapid transformation of D-mannose into orthogonally protected D-glucosamine and D-galactosamine thioglycosides.
abstract: An expedient protocol for synthesis of orthogonally protected 2-azido-2-deoxy-D-glucosamine and 2-azido-2-deoxy-D-galactosamine donors from D-mannose is described. Readily available phenyl β-D-thiomannoside is rapidly transformed into D-GlcN(3) thioglycosides via a highly regioselective 3-O-acylation followed by 4,6-O-benzylidenation and azide displacement of C2-OTf, which is further converted into D-GalN(3) thioglycosides through Lattrell-Dax inversion of the C4 hydroxy group and its Boc protection. The reaction sequence may be completed in 2 days and involves simple workups and minimal column chromatography.
authors.affiliation: Department of Chemistry, Indian Institute of Technology Bombay, Mumbai, India.
authors.forename: Madhu
authors.initials: M
authors.lastname: Emmadi
authors.forename: Suvarn S
authors.initials: SS
authors.lastname: Kulkarni
mesh_terms: D005563:Formic Acid Esters / Q000737:chemistry; D005688:Galactosamine / Q000737:chemistry*; D005944:Glucosamine / Q000737:chemistry*; D007700:Kinetics; D008358:Mannose / Q000737:chemistry*; D013237:Stereoisomerism; D013379:Substrate Specificity; D013865:Thioglycosides / Q000737:chemistry*
chemical_list: D005563:Formic Acid Esters; D013865:Thioglycosides; C000345:t-butyloxycarbonyl group; D005688:Galactosamine; D005944:Glucosamine; D008358:Mannose