Synthesis of two mono-deoxy β-cyclodextrin derivatives as useful tools for confirming DIBAL-H promoted bis-de-O-methylation mechanism  

作　　者：Su Long Xiao De Min Zhou Ming Yang Fei Yu Li He Zhang Pierre Sinay Yong Min Zhang 

机构地区：[1]State Key Laboratory of Natural and Biomimetic Drugs,School of Pharmaceutical Sciences,Peking University [2]Institut Parisien de Chimie Moleculaire,UMR CNRS 7201,Universite Pierre et Marie Curie-Paris 6,4 Place Jussieu [3]Institute for Interdisciplinary Research,Jianghan University,Wuhan Economic and Technological Development Zone

出　　处：《Chinese Chemical Letters》2012年第12期1315-1318,共4页中国化学快报（英文版）

基　　金：Financial support of this study from CNRS is gratefully acknowledged

摘　　要：Diisobutylaluminium hydride （DIBAL-H） promotes secondary rim regioselective bis-de-O-methylation of permethylated β- cyclodextrin （β-CD） to give diol 2. To gain an insight into the mechanism of this remarkable regioselective behavior, two corresponding permethylated β-CDs with an alcohol function at either 2- or 3-position were synthesized in our previous study. As a step further to this work, the two compounds were subjected to deoxygenation reaction with tributyltin hydride in the present of 2,2＇- azobisisobutyronitrile affording the corresponding 2- and 3-deoxy permethylated β-CD derivatives （19 and 16）. The structures of these two compounds were characterized by 1D and 2D NMR and HRMS. Compounds 16 and 19 were unable to react with DIBAL- H which suggests that O-2A and O-3B are necessary for DIBAL-H promoted bis-de-O-methylation reaction of permethylated β-CD.Diisobutylaluminium hydride （DIBAL-H） promotes secondary rim regioselective bis-de-O-methylation of permethylated β- cyclodextrin （β-CD） to give diol 2. To gain an insight into the mechanism of this remarkable regioselective behavior, two corresponding permethylated β-CDs with an alcohol function at either 2- or 3-position were synthesized in our previous study. As a step further to this work, the two compounds were subjected to deoxygenation reaction with tributyltin hydride in the present of 2,2＇- azobisisobutyronitrile affording the corresponding 2- and 3-deoxy permethylated β-CD derivatives （19 and 16）. The structures of these two compounds were characterized by 1D and 2D NMR and HRMS. Compounds 16 and 19 were unable to react with DIBAL- H which suggests that O-2A and O-3B are necessary for DIBAL-H promoted bis-de-O-methylation reaction of permethylated β-CD.

关 键 词：Cyclodextrin （CD） DIBAL-H Deoxy Synthesis MECHANISM 

分 类 号：O636.12[理学—高分子化学]