New α-selective thermal glycosylation of acetyl-protected 2-acetamido-2-deoxy-β-d-glucopyranosyl diphenylphosphinate
作者:Jun-ichi Kadokawa、Takeshi Nagaoka、Jun Ebana、Hideyuki Tagaya、Koji Chiba
DOI:10.1016/s0008-6215(00)00069-0
日期:2000.7
This paper describes new alpha-selective thermal glycosylation using acetyl-protected 2-acetamido-2-deoxy-beta-D-glucopyranosyl diphenylphosphinate (4) as a glycosyl donor. When the glycosylation of 4 with 1-hexanol was carried out under Various conditions, the conditions using trimethylsilyl trifluoromethanesulfonate as a promoter in nitromethane at reflux temperature were most suitable for the formation of the alpha anomer. The glycosylation of 4 with the other common alcohols gave corresponding alpha-glycosides in relatively high yields under the conditions. When cholesterol, a very steric hindered alcohol, was used as a glycosyl acceptor, alpha-glycoside was also produced predominantly. (C) 2000 Elsevier Science Ltd. All rights reserved.