Inter- and intramolecular glycosylation of exo-glycals promoted by metallic Lewis acids
摘要:
exo-Glycosyl carbonates were employed for inter- and intramolecular glycosylation reactions. A number of metallic Lewis Acids and solvents were examined to enhance the reactivity. The optimum conditions were found to be the use of AlCl3 in 1-nitropropane. The method was demonstrated to be useful for the intermolecular glycosyl transfer of several nucleophiles, including simple alcohols, sugars, and amino acid derivatives; however, intramolecular glycosylations were not successful. (c) 2006 Elsevier Ltd. All rights reserved.
Stereoselective glycosylation of d-galactals by diethyl phosphorochloridite- and AlCl3-assisted Ferrier rearrangement
作者:Yen-Bo Chen、Su-I. Wang、Zi-Ping Lin、Chun-Hung Lin、Min-Tsang Hsieh、Hui-Chang Lin
DOI:10.1016/j.tet.2014.11.027
日期:2015.1
α-2,3-Unsaturated galactosides were synthesized in good to excellent yields by the initial activation of d-galactals with diethyl phosphorochloridite and the subsequent glycosyl addition via Ferrier rearrangement with various O-nucleophiles in the presence of AlCl3. The two-step reactions were carried out in one-pot and finished within 60 min in 81–95% yield to give the glycoside products with excellent
Stereoselective glycosylation of exo-glycals by microwave-assisted Ferrier rearrangement
作者:Hui-Chang Lin、Chih-Chun Chang、Jia-Yi Chen、Chun-Hung Lin
DOI:10.1016/j.tetasy.2004.11.044
日期:2005.1
exo-Glycosyl carbonates were shown to be efficient glycosyl donors in microwave-assisted glycosylation. In these reactions alpha-glycosyl additions occurred with excellent stereoselectivity and were complete in 4-8 min with 75-92% yield. Interestingly exo-glycals were found to have higher activity than endo-glycals and common glycosides, the reactions of which can be improved by the addition of Lewis acid to result in a higher yield and enhanced stereo selectivity. (C) 2004 Elsevier Ltd. All rights reserved.
Inter- and intramolecular glycosylation of exo-glycals promoted by metallic Lewis acids
作者:Sheng-Jie Hsu、Hui-Chang Lin、Chun-Hung Lin
DOI:10.1016/j.carres.2006.04.003
日期:2006.7
exo-Glycosyl carbonates were employed for inter- and intramolecular glycosylation reactions. A number of metallic Lewis Acids and solvents were examined to enhance the reactivity. The optimum conditions were found to be the use of AlCl3 in 1-nitropropane. The method was demonstrated to be useful for the intermolecular glycosyl transfer of several nucleophiles, including simple alcohols, sugars, and amino acid derivatives; however, intramolecular glycosylations were not successful. (c) 2006 Elsevier Ltd. All rights reserved.