Chemistry of 1-Alkoxy-1-glycosyl Radicals: Formation of β-Mannopyranosides by Radical Decarboxylation and Decarbonylation of <i>manno</i>-Heptulosonic Acid Glycoside Derivatives
作者:David Crich、Jae-Taeg Hwang、Hongwei Yuan
DOI:10.1021/jo960799q
日期:1996.1.1
A method for the preparation of highly enriched beta-mannopyranosides is described. A glycosyl donor 28 is prepared from tetraallyl mannonolactone by standard means and coupled to a number of primary carbohydrate alcohols, resulting in the isolation in excellent yields of axial disaccharides. Following exchange of the allyl groups for acetyl esters, the furan is oxidatively cleaved with catalytic RuO(2)
描述了一种制备高度浓缩的β-甘露聚糖的方法。通过标准方法由四烯丙基甘露糖内酯制备糖基供体28,并将其与许多伯糖醇偶联,从而以极高的产率获得了轴向二糖。在将烯丙基交换为乙酰基酯后,呋喃被催化RuO(2)和NaIO(4)氧化裂解,所得酸经过Barton脱羧。28与仲醇2,3-异亚丙基-α-L-鼠李糖吡喃糖苷的偶合导致异头异构体化学结构的明显倒置和赤道二糖的分离。