AI Article Synopsis
- The study explores how the placement of O-trifluoroacetyl (TFA) groups on thioglycoside glycosyl donors affects the stereoselectivity during the formation of α-arabinofuranosides, particularly looking at disaccharide development.
- It was found that the combination of TFA and 2-O-(triisopropylsilyl) (TIPS) can enhance 1,2-cis-selectivity in arabinofuranosylation, which is influenced by the type of glycosyl acceptor used.
- The research highlights that the optimal pairing of glycosyl donors and acceptors is essential for achieving both high donor reactivity and desired β-stereoselect
Article Abstract
The influence of O-trifluoroacetyl (TFA) groups at different positions of thioglycoside glycosyl donors on stereoselectivity of α-arabinofuranosylation leading to corresponding disaccharides was studied. It was shown that TFA group in thioglycoside glycosyl donors, when combined with 2-O-(triisopropylsilyl) (TIPS) non-participating group, may be regarded as an electron-withdrawing protecting group that may enhance 1,2-cis-selectivity in arabinofuranosylation, the results strongly depending on the nature of glycosyl acceptor. The reactivities of the glycosyl donors were compared with those of a similar thioglycoside with O-pentafluoropropionyl groups and the known phenyl 3,5-O-(di-tert-butylsilylene)-1-thio-α-d-arabinofuranosides with 2-O-TIPS and 2-O-benzyl groups. The 'matching' in the donor-acceptor combination was found to be critical for achieving both high reactivity of glycosyl donor and β-stereoselectivity of arabinofuranosylation. The use of glycosyl donors with TFA and silyl protection may be useful in the realization of the benzyl-free approach to oligoarabinofuranosides with azido group in aglycon-convenient building blocks for the preparation of neoglycoconjugates.
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| http://dx.doi.org/10.1016/j.carres.2014.05.017 | DOI Listing |
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