<i>o</i>-Xylylene Protecting Group in Carbohydrate Chemistry: Application to the Regioselective Protection of a Single <i>vic</i>-Diol Segment in Cyclodextrins
作者:Patricia Balbuena、Rita Gonçalves-Pereira、José L. Jiménez Blanco、M. Isabel García-Moreno、David Lesur、Carmen Ortiz Mellet、José M. García Fernández
DOI:10.1021/jo302178f
日期:2013.2.15
A systematic study of the suitability of α,α′-dibromo-o-xylene as a reagent for cyclic o-xylylene protection of vic-diols in different monosaccharide substrates is reported. The installation of this protecting group, formally equivalent to a di-O-benzylation reaction, proceeds with good regioselectivity toward 1,2-trans-diequatorial diol systems in pyranose and furanose rings. Initially, the benzyl
α的适宜的系统性研究,α'二溴ø二甲苯作为环状的试剂ö的-xylylene保护VIC -diols在不同单糖底物进行报告。在形式上等同于二-O-苄基化反应的该保护基的安装,对吡喃糖和呋喃糖环中的1,2-反-对-赤基二醇系统具有良好的区域选择性。首先,优先形成更酸性羟基的苄基醚型衍生物。随后在分子上朝着赤道取向邻位OH的分子内醚化是有利的。该方法已被实施用于同时保护单个武器的次要O-2和O-3位置环糊精(CD)家族的环状寡糖(环麦芽六-,-庚-和-八糖;α,β和γCD)中的d-吡喃葡萄糖基单元。