title: First Total Synthesis of Trehalose-Containing Branched Oligosaccharide OSE-1 of Mycobacterium gordonae (Strain 990).
abstract: The first total synthesis of the branched oligosaccharide OSE-1 of Mycobacterium gordonae (strain 990) is reported. An intramolecular aglycon delivery approach was used for constructing the desymmetrized 1,1'-α,α-linked trehalose moiety. A [3+2] glycosylation of the trisaccharide donor and trehalose acceptor furnished the right hand side pentasaccharide. Regioselective O3 glycosylation of L-rhamnosyl 2,3-diol allowed expedient synthesis of the left hand side tetrasaccharide. The nonasaccharide was assembled in a highly convergent fashion through a [4+5] glycosylation.
authors.affiliation: Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, 400076 (India).
authors.forename: Manishkumar A
authors.initials: MA
authors.lastname: Chaube
authors.affiliation: Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, 400076 (India). suvarn@chem.iitb.ac.in.
authors.forename: Suvarn S
authors.initials: SS
authors.lastname: Kulkarni
mesh_terms: D002240:Carbohydrate Sequence; D006031:Glycosylation; D008070:Lipopolysaccharides / Q000138:chemical synthesis* / Q000737:chemistry*; D009170:Nontuberculous Mycobacteria / Q000737:chemistry*; D009844:Oligosaccharides / Q000138:chemical synthesis* / Q000737:chemistry; D014199:Trehalose / Q000138:chemical synthesis* / Q000737:chemistry*
chemical_list: D008070:Lipopolysaccharides; D009844:Oligosaccharides; C023023:lipid-linked oligosaccharides; D014199:Trehalose
keywords: 1,1′-α,α-glycosylation; Mycobacterium gordonae; regioselective glycosylation; total synthesis; trehalose oligosaccharides