Stereospecific Ester Activation in Nitrite-Mediated Carbohydrate Epimerization
作者:Hai Dong、Zhichao Pei、Olof Ramström
DOI:10.1021/jo052662i
日期:2006.4.1
essential for the reactivity of the nitrite-mediated triflate inversion. Furthermore, a good inversion yield also depended on the relative configuration of the neighboring ester group to the triflate. Only with the ester group in the equatorial position, whatever the configuration of the triflate, did the reaction proceed smoothly, whereas a neighboring axial ester group proved largely inefficient. The
Supramolecular Control in Carbohydrate Epimerization: Discovery of a New Anion Host−Guest System
作者:Hai Dong、Martin Rahm、Tore Brinck、Olof Ramström
DOI:10.1021/ja807044p
日期:2008.11.19
A new anion-carbohydrate recognition system is described. Pyranosides with axial protons in 1-, 3-, and 5-position proved efficient, forming relatively strong complexes between the anion and the B-face of the carbohydrate. This system could furthermore be used in supramolecular control in Lattrell-Dax epimerization reactions, leading to either activation or deactivation effects.