Rapid Transformation of d-Mannose into Orthogonally Protected d-Glucosamine and d-Galactosamine Thioglycosi

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• 作者：Madhu Emmadi ; Suvarn S. Kulkarni
• 刊名：Journal of Organic Chemistry
• 出版年：2011
• 出版时间：June 3, 2011
• 年：2011
• 卷：76
• 期：11
• 页码：4703-4709
• 全文大小：835K
• 年卷期：v.76,no.11(June 3, 2011)
• ISSN：1520-6904

文摘

An expedient protocol for synthesis of orthogonally protected 2-azido-2-deoxy-d-glucosamine and 2-azido-2-deoxy-d-galactosamine donors from d-mannose is described. Readily available phenyl 尾-d-thiomannoside is rapidly transformed into d-GlcN₃ thioglycosides via a highly regioselective 3-O-acylation followed by 4,6-O-benzylidenation and azide displacement of C2-OTf, which is further converted into d-GalN₃ thioglycosides through Lattrell鈥揇ax inversion of the C4 hydroxy group and its Boc protection. The reaction sequence may be completed in 2 days and involves simple workups and minimal column chromatography.