The catalyticasymmetric total synthesis of (−)‐exiguolide, a complex 20‐membered macrolide embedded with a bis(tetrahydropyran) motif, is reported. The convergent synthesisinvolves the construction of the C1–C11 tetrahydropyran segment via catalyticasymmetric allylation and Prins cyclization, and the formation of the C12–C21 phosphonate segment via catalyticasymmetric cyclocondensation reaction
Application of Stereoselective Ether Transfer to the Synthesis of Isotactic Polyethers
作者:Kai Liu、Joseph W. Arico、Richard E. Taylor
DOI:10.1021/jo100094d
日期:2010.6.18
the synthesis of a series of naturally occurring isotactic polymethoxy compounds. Ethertransfer followed by a hydride workup enables simultaneous, diastereoselective production of two methoxy centers in a single step. High yields and diastereoselectivity are observed even in stereochemically rich, polyoxygenated systems. Direct generation of bis-methyl ether moieties from methoxymethyl ethers minimizes
Asymmetric Total Synthesis
of (+)-Brefeldin A: Intramolecular Epoxide-Opening/RCM
Strategy
作者:Jinsung Tae、Myung-Yeol Kim、Hyemi Kim
DOI:10.1055/s-0029-1216723
日期:——
A highly efficientasymmetric total synthesis of (+)-brefeldin A was accomplished by using intramolecular epoxide opening of an epoxy allylsilane and RCM reaction for the constructions of the cyclopentane and macrocyclic lactone rings of (+)-brefeldin A, respectively.
通过使用环氧烯丙基硅烷的分子内环氧化物开环和 RCM 反应分别构建 (+)-brefeldin A 的环戊烷和大环内酯环,实现了 (+)-brefeldin A 的高效不对称全合成。
Process for trans-6-(2-(substituted-pyrrol-1-yl)alkyl)pryan-2-one
申请人:Warner-Lambert Company
公开号:US05003080A1
公开(公告)日:1991-03-26
An improved process for the preparation of trans-6-[2-(substituted-pyrrol-1-yl)alkyl]pyran-2-ones by a novel synthesis is described where 1,6-heptadien-4-ol is converted in eight operations to the desired products, as well as an improved process for the preparation of (2R-trans) and trans-(.+-.)-5-(4-fluorophenyl)-2-(1-methylethyl)-N-4-diphenyl-1-[2-tetrah ydro-4-hydroxy-6-oxo-2H-pyran-2-yl)ethyl]-1H-pyrrole-3-carboxamide by a novel synthesis where 4-methyl-3-oxo-N-phenylpentanamide is converted in eight operations to the desired product or alternatively 4-fluoro-.alpha.-[2-methyl-1-oxopropyl]-.gamma.-oxo-N,.beta.-diphenylbenze nebutaneamide is converted in one step to the desired product, and additionally, a process for preparing (2R-trans)-5-(4-fluorophenyl)-2-(1-methylethyl)-N,4-diphenyl-1-[2-(tetrahy dro-4-hydroxy-6-oxo-2H-pyran-2-yl)ethyl]-1H-pyrrole-3-carboxamide from (R)-4-cyano-3-[[(1,1-dimethylethyl)dimethylsilyl]oxy]butanoic acid, as well as other valuable intermediates used in the processes.