Cyclization of hydroxy enol ethers: a stereocontrolled approach to 3-deoxy-D-manno-2-octulosonic acid containing disaccharides
作者:Arnaud Haudrechy、Pierre Sinay
DOI:10.1021/jo00041a017
日期:1992.7
A method for the preparation of the carboxylic acids 14 and 15 has been developed, starting from known 2,3,5,6-di-O-isopropylidene-D-mannofuranose. Esterification of 14 and 15 with methanol, methyl 2,3,4-tri-O-benzyl-alpha-D-glucopyranoside, and 1,2,5,6-di-O-isopropylidene-alpha-D-glucofuranose, followed by reaction with Tebbe reagent and selective deprotection gave, respectively, the key complex hydroxy enol ethers 20, 26, and 35. Stereoselective iodocyclization, followed by transformation of the CH2I appendage into a methyloxycarbonyl group, gave the corresponding protected KDO-containing disaccharides.