Unified Synthesis of Eudesmanolides, Combining Biomimetic Strategies with Homogeneous Catalysis and Free-Radical Chemistry
作者:Alejandro F. Barrero、Antonio Rosales、Juan M. Cuerva、J. Enrique Oltra
DOI:10.1021/ol034510k
日期:2003.5.1
[reaction: see text] A general procedure for the synthesis of both 12,6- and 12,8-eudesmanolides has been developed. The key step is the titanocene-catalyzed radical cyclization of accessible epoxygermacrolides. The novel reagent 2,4,6-trimethyl-1-trimethylsilylpyridinium chloride, both compatible with oxiranes and capable of regenerating Cp(2)TiCl(2) from Cp(2)Ti(Cl)H and Cp(2)Ti(Cl)OAc, played an
[反应:见正文]已经开发了合成12,6-和12,8-十二烷内酯的通用方法。关键步骤是钛环茂金属催化可及的环氧锗烷的自由基环化。新型试剂2,4,6-三甲基-1-三甲基甲硅烷基吡啶鎓氯化物,与二恶英兼容,能够从Cp(2)Ti(Cl)H和Cp(2)Ti(Cl)再生Cp(2)TiCl(2) )OAc在导致环外烯烃的催化循环中起着重要作用。