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Improvement of the stereoselectivity of the glycosylation reaction with 2-azido-2-deoxy-1-thioglucoside donors
•A 6-O-chloroacetyl group on the thioglucopyranoside afforded higher α-selectivity.•Several structural distinct acceptors were used.•The nature of the acceptor was found to be critical to the stereoselectivity. 2-Azido-2-deoxy-1-thioglucoside donors with an electron withdrawing group at position 6 w...
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Published in: | Carbohydrate research 2016-05, Vol.426, p.33-39 |
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Main Authors: | , |
Format: | Article |
Language: | English |
Subjects: | |
Citations: | Items that this one cites Items that cite this one |
Online Access: | Get full text |
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Summary: | •A 6-O-chloroacetyl group on the thioglucopyranoside afforded higher α-selectivity.•Several structural distinct acceptors were used.•The nature of the acceptor was found to be critical to the stereoselectivity.
2-Azido-2-deoxy-1-thioglucoside donors with an electron withdrawing group at position 6 were employed to study the stereoselectivity of the glycosylation reaction with several acceptors, ranging from unhindered small primary alcohols to other sugars and steroids, using NIS/TfOH as promoter. p-Tolyl 2-azido-3,4-di-O-benzyl-6-O-chloroacetyl-2-deoxy-1-thio-α/β-D-glucopyranoside afforded the higher α-selectivity, showing that a stronger electron withdrawing ester at O-6 influenced the anomeric selectivity towards the 1,2-cis glucosides. The anomeric stereoselectivity was highly dependent on the acceptor. |
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ISSN: | 0008-6215 1873-426X |
DOI: | 10.1016/j.carres.2016.03.021 |