Propargyl mediated intramolecular aglycon delivery (IAD): applications to the synthesis of core N-glycan oligosaccharides |
| |
Institution: | Chemistry Research Laboratory, Oxford University, Mansfield Road, Oxford OX1 3TA, UK |
| |
Abstract: | The use of propargyl mediated intramolecular aglycon delivery (IAD) for the synthesis of the key Manβ(1→4)GlcNAc linkage of N-glycan oligosaccharides, including the core N-glycan pentasaccharide, is investigated. Isomerisation of a 2-O-progargyl group of manno thioglycoside donors to an allene is followed by iodonium ion mediated mixed acetal formation with the 4-OH of protected GlcNAc acceptors, and subsequent intramolecular glycosylation occurs with complete control of anomeric stereochemistry to form the Manβ(1→4)GlcNAc linkage. A variety of linear and convergent approaches (1+2, 3+1, 3+2) to the core pentasaccharide are investigated as means of probing the generality and limitations of this type of intramolecular aglycon delivery for the formation of β-mannoside linkages in complex oligosaccharides. |
| |
Keywords: | |
本文献已被 ScienceDirect 等数据库收录! |
|