From glycoside hydrolases to thioglycoligases: the synthesis of thioglycosides
作者:Robert V. Stick、Keith A. Stubbs
DOI:10.1016/j.tetasy.2004.12.004
日期:2005.1
any thioglycosides––only the products of O-glycosylation were formed. However, thioglycosides were formed when a thioglycoligase was used to mediate the reaction between acceptor and donor. In fact, pyranose acceptors possessing a thiol group at C3, C4 or C6 (but not C2) were all capable of conversion into thioglycosides. Some comment is given regarding the mechanism of the various processes.
Iodine-catalyzed one-pot acetalation–esterification reaction for the preparation of orthogonally protected glycosides
作者:Rachel A. Jones、Robert Davidson、Anh Tuan Tran、Nichola Smith、M. Carmen Galan
DOI:10.1016/j.carres.2010.07.010
日期:2010.9
An iodine-catalyzed one-pot tandem acetalation-esterification reaction of thio- and O-glycosides has been developed providing a fast and mild route to orthogonally protected glycosides ready to be used as building blocks in glycosylation reactions.
Evidence for Endocyclic Cleavage of Conformationally Restricted Glycopyranosides
作者:Shino Manabe、Kazuyuki Ishii、Daisuke Hashizume、Hiroyuki Koshino、Yukishige Ito
DOI:10.1002/chem.200900064
日期:2009.7.13
reaction is caused by endocycliccleavage of the pyranosides. Evidence for endocycliccleavage of conformationallyrestricted pyranosides in the chair form was obtained by intra‐ and intermolecular Friedel–Crafts reactions, chloride addition, and reduction of the generated cation. On the other hand, pyranosides with the distorted conformation were never cleaved in an endocyclic manner.
Fast oxidation of thioglycosides to glycosyl sulfones using KMnO4/CuSO4·5H2O under neutral reaction conditions
作者:Geetanjali Agnihotri、Anup Kumar Misra
DOI:10.1016/j.carres.2005.11.025
日期:2006.2
A rapid oxidation of thioglycosides to glycosyl sulfones has been achieved using a combination of KMnO4 and CuSO(4)center dot 5H(2)O in acetonitrile and water. This reaction protocol has many advantages compared to other methods available for this transformation, including compatibility with acid and base labile functional groups used for the protection of carbohydrates, high yields, fast reaction times, and moderate reaction temperatures. The yields obtained were excellent in all cases. (c) 2005 Elsevier Ltd. All rights reserved.