Combined Effect of the Picoloyl Protecting Group and Triflic Acid in Sialylation
作者:Samira Escopy、Scott A. Geringer、Cristina De Meo
DOI:10.1021/acs.orglett.7b00976
日期:2017.5.19
The stereoselective synthesis of sialosides is still one of the major challenges in carbohydrate chemistry. The synthesis and glycosidation of novel sialyl donors bearing a picoloyl substituent at C-4 are reported. High stereoselectivities and faster reactions were observed in the presence of an excess of triflic acid. The acid excess does not have the same effect on conventional sialyl donors, which
The potential of an N-Troc-protected sialicaciddonor, equipped with phenylsulfenyl functionality as a leaving group, has been explored. As a result, the entitled donor was proven to be highly reactive and to have broad applicability toward the synthesis of variant sialo-glycans, which have N-glycolyl, de-N-acetyl, 1,5-lactam and 8-O-sulfo sialicacid analogs.
A convergent synthesis of core 2 branched sialylated and sulfated oligosaccharides
作者:Jie Xia、James L Alderfer、Thamarapu Srikrishnan、E.V Chandrasekaran、Khushi L Matta
DOI:10.1016/s0968-0896(02)00246-8
日期:2002.11
sialylation was accomplished using donor 10 with defined configuration established through X-ray crystallographic analysis. Target oligosaccharides 1-3 were then obtained by the systematic deprotection of intermediates 24, 27 and 29. With these target oligosaccharides 1-3 obtained, biological evaluations of these molecules as enzyme substrates was undertaken and selectin binding studies are planned
Application of 4,5-O,N-oxazolidinone protected thiophenyl sialosyl donor to the synthesis of α-sialosides
作者:Michael D. Farris、Cristina De Meo
DOI:10.1016/j.tetlet.2006.12.061
日期:2007.2
The synthesis of a novel oxazolidinone sialosyl donor is reported. The introduction of a trans-fused ring enhances reactivity and stereoselectivity in glycosylation reactions for the synthesis of alpha-sialosides. The oxazolidinone ring can also be removed under basic conditions to afford the deprotected amine, which can be further functionalized. (c) 2006 Elsevier Ltd. All rights reserved.