Stereoselective synthesis of substituted ketopyranose subunits of polyketide natural products by intramolecular alkoxycarbonylation of δ-alkynyl alcohols
作者:James A. Marshall、Mathew M. Yanik
DOI:10.1016/s0040-4039(00)00705-x
日期:2000.6
Upon treatment with 5 mol% Pd(MeCN)(2)Cl-2 in methanol containing 1.1-1.5 equiv. of p-benzoquinone under 1 atm of CO, delta-hydroxy alkynes are converted to methyl ketopyranosides with excellent stereoselectivity. The reaction proceeds by sequential intramolecular alkoxypalladation of the alkyne followed by CO insertion and methanolysis, then an ensuing Pd+2-catalyzed 1,4-addition of methanol to the intermediate conjugated ester. (C) 2000 Elsevier Science Ltd. All rights reserved.