First O-Glycosylation from Unprotected 1-Thioimidoyl Hexofuranosides Assisted by Divalent Cations

详细信息    查看全文

• 作者：Ronan Euzen ; Jean-Paul Gué ; gan ; Vincent Ferri&egrave ; res ; Daniel Plusquellec
• 刊名：Journal of Organic Chemistry
• 出版年：2007
• 出版时间：July 20, 2007
• 年：2007
• 卷：72
• 期：15
• 页码：5743 - 5747
• 全文大小：84K
• 年卷期：v.72,no.15(July 20, 2007)
• ISSN：1520-6904

文摘

The preparation of O-hexofuranosides was accomplished from unprotected 1-thioimidoyl furanosides asdonors. The present methodology was first used for the synthesis of octyl galactofuranoside and furtherextended to D-galactofuranose-containing disaccharides. Within this study, we emphasized the need foradditional complexing cations to maintain the furanose ring in its initial size. After experimentation,calcium ion was first used concomitantly with trimethylsilyl trifluoromethanesulfonate, the latter beingable to activate the thioimidate and the former being likely to inhibit ring expansion. Moreover, animprovement was performed by using copper(II) trifluoromethanesulfonate which could then meet therequirements as both promoter and complexing agent.