Teubrevin G and Teubrevin H: The First Total Syntheses of Rearranged <i>n</i><i>eo</i>-Clerodanes Including Solutions to the Problems of Chirality Merger and Furan Ring Assembly
作者:Leo A. Paquette、Ivan Efremov
DOI:10.1021/ja010313+
日期:2001.5.1
of a 1,3-dimesityl-4,5-dihydroimidazol-2-ylideneruthenium precatalyst. The key building blocks 39 and 48 were constructed by asymmetric processes and coupled under conditions where good remote asymmetric induction was realized. The diastereoselection observed in this alkylation reaction appears to be intimately associated with the conformational properties of the beta-keto ester enolate. While the readily
描述了 teubrevins G (2) 和 H (3) 的全合成。报道的策略依赖于高度区域选择性的环加成 - 断裂方法来构建 2,3,4-三取代呋喃,并通过应用 1,3-dimesityl-4,5- 实现高效的闭环复分解化学二氢咪唑-2-亚基钌预催化剂。关键构建块 39 和 48 是通过非对称过程构建的,并在实现良好远程非对称感应的条件下耦合。在该烷基化反应中观察到的非对映选择似乎与 β-酮酯烯醇化物的构象特性密切相关。虽然容易分离的主要非对映异构体通过短路径转化为 2,但次要组分作为 3 的前体。