Atom-Economic and Stereoselective Syntheses of the Ring A and B Subunits of the Bryostatins
作者:Barry M. Trost、Hanbiao Yang、Cheyenne S. Brindle、Guangbin Dong
DOI:10.1002/chem.201002930
日期:2011.8.22
subunits of bryostatins. A Ru‐catalyzedtandem alkene–alkyne coupling/Michael addition reaction was developed and applied to the synthesis of bryostatin ring B. We explored an acetylide‐mediated epoxide‐opening/6‐exo‐dig cyclization route to access the bryostatin ring A, although ring A was eventually furnished through an acid‐catalyzedtandem transketalization/ketalization sequence. In addition, a dinuclear
本文描述了苔藓抑素环 A 和 B 亚基立体选择性组装的化学选择性和原子经济方法。钌催化的串联烯烃-炔耦合/迈克尔加成反应的开发和应用到苔藓抑素环B的合成我们探讨乙炔化介导的环氧化物的开/ 6-外型-挖环化路径访问的苔藓抑素环A,虽然环 A 最终通过酸催化的串联转缩酮/缩酮化序列提供。此外,还评估了双核锌催化甲基乙烯基酮(MVK)羟醛策略用于构建聚乙酸酯部分。这些方法的使用最终导致了包含环 A 和 B 亚基的北部苔藓抑素片段的快速组装。
A Ru-Catalyzed Tandem Alkyne−Enone Coupling/Michael Addition: Synthesis of 4-Methylene-2,6-<i>cis</i>-tetrahydropyrans
作者:Barry M. Trost、Hanbiao Yang、Georg Wuitschik
DOI:10.1021/ol0520065
日期:2005.10.1
[reaction: see text] A Ru-catalyzed tandem alkyne-enone coupling/Michael addition reaction is reported. It provides an efficient, atom-economic entry to 4-methylene-2,6-cis-tetrahydropyrans from simple, readily available homopropargylic alcohols and beta,gamma-unsaturated enones in good yields. Further functionalization of the resultant vinylsilane leads to the synthesis of either geometrically defined