Van Orden Lori J, Patterson Brian D, Rychnovsky Scott D
Department of Chemistry, 1102 Natural Sciences II, University of California-Irvine, Irvine, CA 92697, USA.
J Org Chem. 2007 Jul 20;72(15):5784-93. doi: 10.1021/jo070901r. Epub 2007 Jun 27.
A total synthesis of the marine natural product leucascandrolide A has been completed. The titanium tetrabromide-mediated Mukaiyama aldol-Prins (MAP) reaction with aldehydes developed in our group provided a highly convergent and stereoselective method for assembling the core of the molecule. A new class of MAP reactions with acetals is introduced, and mechanistic considerations for both MAP methods are described. The total synthesis was completed by coupling of the side chain through two avenues: a known Still-Gennari olefination and a new Z-selective aldol/dehydroselenation reaction. Both procedures were highly selective and provided the natural product.
海洋天然产物白海绵内酯A的全合成已完成。我们小组开发的四溴化钛介导的与醛的向山羟醛-Prins(MAP)反应为组装该分子核心提供了一种高度汇聚且立体选择性的方法。引入了一类新的与缩醛的MAP反应,并描述了两种MAP方法的机理考量。通过两条途径连接侧链完成了全合成:一种是已知的斯蒂尔-根纳里烯化反应,另一种是新的Z-选择性羟醛/脱氢硒化反应。这两种方法都具有高度选择性,并得到了天然产物。