Synthesis of N,N-Ac,Boc laurylthio sialoside and its application to O-sialylation
作者:Kiyoshi Ikeda、Keisuke Miyamoto、Masayuki Sato
DOI:10.1016/j.tetlet.2007.08.088
日期:2007.10
The combination of the 5-N-tert-butoxycarbonyl (Boc) group of laurylthio sialoside and cyclopentyl methyl ether (CPME) as a solvent enhanced the reactivity and alpha-selectivity of the sialyl donor during sialylation. Selective deprotection of the N-Boc group of sialoside, including an acid-sensitive isopropylidene function, was successfully achieved by Yb(OTf)(3)-SiO2. Transformation of NN-Ac,Boc into an N-acetylglycolyl group of sialoglycoside was easily performed via selective N-deacylation of the mixed Ac-N-Boc carbamate, subsequent Boc group removal, and acylation. (C) 2007 Elsevier Ltd. All rights reserved.