title: Chemical synthesis of the tetrasaccharide repeating unit of the O-polysaccharide isolated from Azospirillum brasilense SR80.
abstract: A linear strategy has been developed for the synthesis of the tetrasaccharide repeating unit of the O-polysaccharide from Azospirillum brasilense SR80. Stepwise glycosylation of the rationally protected thioglycoside donors activated by NIS in the presence of La(OTf)3 furnished the target tetrasaccharide. The glycosylation reactions resulted in the formation of the desired linkage with absolute stereoselectivity and afforded the required derivatives in good to excellent yields. The phthalimido group has been used as the precursor of the desired acetamido group to meet the requirement of 1,2-trans glycosidic linkage.
authors: Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur 741246, India.
authors: Vikramjit
authors: V
authors: Sarkar
authors: Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur 741246, India. Electronic address: sugarnet73@hotmail.com.
authors: Balaram
authors: B
authors: Mukhopadhyay
mesh_terms: D015806:Azospirillum brasilense / Q000737:chemistry; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002384:Catalysis; D008969:Molecular Sequence Data; D019081:O Antigens / Q000737:chemistry*; D009844:Oligosaccharides / Q000138:chemical synthesis*
chemical_list: D019081:O Antigens; D009844:Oligosaccharides
keywords: Acetamido sugars; Bacterial O-polysaccharide; La(OTf)(3)