Synthesis of natural pulvinic acids based on a '3+2 cyclization-Suzuki cross-coupling' strategy

摘要

A number of pulvinic acid natural products were prepared based on Suzuki cross coupling reactions of alpha-hydroxy-gamma-alkylidenebutenolides which are readily available by cyclization of 1,3-bis-silyl enol ethers with oxalyl chloride. The formal total synthesis of pulvinic acid, atromentic acid, gomphidic acid and of 4-hydroxypulvinic acid, 4'-hydroxypulvinic acid and iso-gomphidic acid are reported. In addition, total syntheses of pinastric acid, xerocomic acid and variegatic acid were accomplished. (C) 2005 Elsevier Ltd. All rights reserved.