1-<i>O</i>-Vinyl Glycosides via Tebbe Olefination, Their Use as Chiral Auxiliaries and Monomers
作者:Jialong Yuan、Kristof Lindner、Holger Frauenrath
DOI:10.1021/jo0600510
日期:2006.7.1
perspective to use the 1-O-vinyl glycosides as monomers for the preparation of glycosylated poly(vinyl alcohol) derivatives with controlled tacticity, their scope as chiral auxiliaries for a stereodifferentiation in addition reactions to the olefin function was investigated by using the [2+2] cycloaddition to dichloroketene as a model reaction. In particular, vinyl 2,3,4,6-tetra-O-benzoyl-α-d-mannopyranoside
制备了一系列的端基纯的1- O-甲酰基糖苷1,并通过Tebbe烯化将其转化为相应的1- O-乙烯基糖苷2。以良好的收率获得了未取代的乙烯基糖苷,为异构体纯的化合物,其制备方法与多种官能团的存在相容。显着地,在乙酸盐和苯甲酸酯保护基的存在下,将异头甲酸酯基区域选择性地转化为相应的烯烃。用角度来看要用1- O-乙烯基糖苷作为单体,用于制备具有可控制的立构规整度的糖基化聚乙烯醇衍生物,通过使用[2 + 2]环化成二氯乙烯酮的方法研究了它们作为立体分化的手性助剂的范围以及对烯烃功能的加成反应。模型反应。特别地,乙烯基2,3,4,6-四-O-苯甲酰基-α - d-甘露吡喃糖苷(2i)表现出优异的非对映选择性。最后,1- ø -乙烯基苷成功经受大量的自由基均聚或用作与马来酸酐自由基共聚得到交替富电子的共聚单体,糖基化的聚(乙烯醇- ALT -马来酸酐)。