Total syntheses of (-)-herbertenediol, (-)-mastigophorene A, and (-)-mastigophorene B. Combined utility of chiral bicyclic lactams and chiral aryl oxazolines
Total syntheses of (-)-herbertenediol, (-)-mastigophorene A, and (-)-mastigophorene B. Combined utility of chiral bicyclic lactams and chiral aryl oxazolines
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DOI：
10.1021/ja984182x
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发表时间：
1999-03-31
影响因子：
15
通讯作者：
Meyers, AI
中科院分区：
文献类型：
--
作者：
Degnan, AP;Meyers, AI
一个非外消旋的双环内酰胺被用来构建一个手性环戊烷，它含有光学纯的邻位的季碳中心，这是所有标题化合物所共有的。然后利用恶唑啉介导的不对称Ullmann偶联反应建立了关于马鞭草烯A和B的联芳轴的手性。通过这个合成过程，清楚地证明了较小的手性辅助剂会导致更高水平的不对称Ullmann偶联，这是以前未知的不对称Ullmann偶联现象。
A nonracemic bicyclic lactam has been used to construct a chiral cyclopentane containing vicinal quaternary carbon centers in optically pure form, which is common to all of the title compounds. An oxazoline-mediated asymmetric Ullmann coupling was then utilized to establish chirality about the biaryl axis of mastigophorenes A and B. Through the course of this synthesis, it was clearly demonstrated that smaller chiral auxiliaries lead to higher levels of atroposelection, a previously unknown phenomenon of the asymmetric Ullmann coupling.