Oxazolidinone Protected 2-Amino-2-deoxy-d-glucose Derivatives as Versatile Intermediates in Stereoselective Oligosaccharide Synthesis and the Formation of α-Linked Glycosides

A Highly α‐Stereoselective Synthesis of Oligosaccharide Fragments of the Vi Antigen from Salmonella typhi and Their Antigenic Activities

“…Synthesis: Since oxazolidinone-protected glucosamine as an a-selective glycosyl donor was first described by the Kerns group, [9] subsequent investigations have been focused on its N-acetyl analogues, confirming that the ring-fused oxazolidiAbstract: In this paper, a convenient approach to the synthesis of the repeating a-(1!4)-linked N-acetyl galactosaminuronic acid units from the capsular polysaccharide of Salmonella typhi is reported. The exclusively a-stereoselective glycosylation reactions were achieved by using oxazolidinone-protected glycosides as building blocks based on a pre-activation protocol.…”

C‐5 Modified S‐Benzoxazolyl Sialyl Donors: Towards More Efficient Selective Sialylations

“…We found that the synthesis of sialyl donors 1b-d could be achieved by direct conversion of the respective C-5 modified thiophenyl donors 4b-d [15][16][17] in the presence of iodine chloride followed by treatment with 2-mercaptobenzoxazole (in the presence of DIPEA) or its potassium salt in the presence of 18-crown-6 (Scheme 2). In our previous study we reported [6] that the coupling between SBox sialyl donor 1a and diacetone galactose acceptor 5 in the presence of N-iodosuccinimide (NIS) and triflic acid in acetonitrile gives disaccharide 6a with a good yield of 70 % ( Table 1, Entry 1).…”

A First Total Synthesis of a Hybrid‐Type Ganglioside Associated with Amyotrophic Lateral Sclerosis‐Like Disorder

“…The Troc group was chosen as the directing functionality for stereoselective b-glucosaminylation and also as a temporary protecting group for the C3 hydroxyl group, thus leading to structure 7, which was synthesized from the reported compound 13 [10] through benzylidanation and introduction of the Troc group at the C3 hydroxyl group of 14 (Scheme 4). [11] To establish the hybrid branches stemming from the galactose residue, the GlcN donor 7 was first reacted with the 3',4'-diol lactose acceptor 9, aiming for regioselective glycosylation at the more reactive C3 hydroxyl group rather than at the C4 hydroxyl group.…”