Synthesis of 3,4,5-trimethoxyphenyl 5″-O-caffeoyl-β-d-erythro-apiofuranosyl-(1→6)-β-d-glucopyranoside: Kelampayoside B
作者:Howard I. Duynstee、Martijn C. de Koning、Gijs A. van der Marel、Jacques H. van Boom
DOI:10.1016/s0040-4039(98)00673-x
日期:1998.6
Chemoselective NIS/ cat. TfOH-mediated glycosylation of ethyl 2,3,4-tri-O-benzoyl-1-thio-beta-D-glucopyranoside (4) with ethyl 2,3-di-O-acetyl-5-O-benzyl-1-thio-alpha/beta-D-erythro-apiofuranoside (3) gave dimer 5 in an excellent yield. BF3Et2O-catalysed condensation of the alpha-trichloroacetimidate 18, accessible in two steps from 5, with 3,4,5-trimethoxyphenol gave beta-linked derivative 19 which could be transformed in five steps into the title compound. (C) 1998 Elsevier Science Ltd. All rights reserved.