A new oxa-Michael reaction and a gold-catalysed cyclisation en route to C-glycosides
摘要:
Two new syntheses of benzyl C-glycosides have been developed. The first one involves an unprecedented oxa-Michael cyclisation and the second one relies on an efficient gold-catalysed ring-closure. (c) 2013 Elsevier Ltd. All rights reserved.
Stereochemistry in the Synthesis and Reaction of <i>e</i><i>xo</i>-Glycals
作者:Wen-Bin Yang、Yu-Ying Yang、Yu-Feng Gu、Shwu-Huey Wang、Che-Chien Chang、Chun-Hung Lin
DOI:10.1021/jo0255227
日期:2002.5.1
Two general methods are explored for the stereoselective synthesis of exo-glycals. One method utilizes a nucleophilic addition of fully protected sugar lactones of gluco-, galacto-, and manno-types, followed by the subsequent dehydration, to give the desired exo-glycals with (Z)-configuration. The other method proceeds with selenylation of C-glycosides in a stereoselective manner. The subsequent selenoxide
Stereoselective Palladium-Catalyzed Arylation of <i>Exo</i>-Glycals with Aryl Iodides
作者:Jeffery Regier、Supriya Ghanty、Yuri Bolshan
DOI:10.1021/acs.joc.1c02533
日期:2022.1.7
A novel methodology for the arylation of exo-glycals has been developed. A range of exo-glycals underwent reactions with aryl iodides in the presence of a palladium catalyst. The transformation proceeded in a stereoselective manner to afford Z-isomers. The developed transformation demonstrated excellent functional group tolerance.
作者:Wen-Bin Yang、Chung-Yi Wu、Che-Chien Chang、Shwu-Huey Wang、Chin-Fen Teo、Chun-Hung Lin
DOI:10.1016/s0040-4039(01)01427-7
日期:2001.9
efficient methods were explored for the synthesis of various conjugated exo-glycals: (i) by nucleophilic addition of sugar lactones with a subsequent dehydration, and (ii) by selenylation of C-glycosides with a subsequent selenoxide elimination. These reactions occurred in a stereoselective manner to give exclusively or predominantly the (Z)-isomers of exo-glycals.
Stereoselective Synthesis of 1,2‐
<i>cis</i>
‐Glycosyl Sulfones and Their Application in One‐Pot Julia Olefination for the Synthesis of
<i>exo</i>
‐Glycals
stereoselective synthesis of 1,2-cis-glycosyl sulfones and their application to one-pot Julia olefination are reported. Glycosylation of heteroarylthiols using glycosyl iodides as glycosyl donors afforded heteroaryl 1-thioglycosides in a highly 1,2-cis-selective manner. 1,2-cis-Glycosyl sulfones were obtained by oxidation of the resulting 1-thioglycosides by magnesium monoperphthalate. One-pot Julia olefination
报道了 1,2-顺式糖基砜的立体选择性合成及其在单锅 Julia 烯化中的应用。使用糖基碘作为糖基供体的杂芳基硫醇的糖基化以高度 1,2-顺式选择性方式提供杂芳基 1-硫代糖苷。1,2-顺式-糖基砜通过用单过苯二甲酸镁氧化所得1-硫代糖苷获得。一锅Julia烯使用1,2-顺糖基砜家具外-glycals与é / Z ^达的选择性91:9。