An Expeditious Route to<i>Streptococci</i>and<i>Enterococci</i>Glycolipids<i>Via</i>Ring-Opening of 1,2-Anhydrosugars with Protic Acids
作者:C. M. Timmers、N. C.R. van Straten、G. A. van der Marel、J. H. van Boom
DOI:10.1080/07328309808002906
日期:1998.4
1,2-Anhydroglucose 6 reacts smoothly and with a high degree of stereoselectivity with a variety of carboxylic and phosphoric acids resulting in the formation of the predominantly beta-oriented 1-O-acyl and 1-O-phosphorylglucoses 7-17. This methodology has been successfully applied in the construction of glycolipids 1a,b. Ring-opening of the 1,2-anhydroglucose derivative 19 with benzoic acid furnished exclusively the beta-aligned key intermediate 20. Subsequent ICDT-assisted chemoselective alpha-glucosylation of 20 with thioethyl donor 21, followed by glycosidation of kojibiosyl benzoate 22 with glycerol acceptor 23 gave the fully protected alpha-diglucosyl glycerol derivative 25, which upon desilylation (-->28), acylation (-->29 or 30) and deprotection afforded the target glycolipids 1a-b in high overall yield.