Department of Chemistry , Ludwig-Maximilians-University Munich , Butenandtstrasse 5-13 , 81377 Munich , Germany.
Institute of Organic Chemistry and Center for Molecular Biosciences , University of Innsbruck , Innrain 80-82 , 6020 Innsbruck , Austria.
J Am Chem Soc. 2018 Jul 11;140(27):8444-8447. doi: 10.1021/jacs.8b06228. Epub 2018 Jul 2.
Salimabromide is an antibiotic polyketide that was previously isolated from the obligate marine myxobacterium Enhygromyxa salina, and its densely functionalized and conformationally rigid tetracyclic framework is unprecedented in nature. Herein we report the first chemical synthesis of the target structure by employing a series of well-orchestrated, robust transformations, highlighted by an acid-promoted, powerful Wagner-Meerwein rearrangement/Friedel-Crafts cyclization sequence to forge the two adjacent quaternary carbon centers embedded in the tetrahydronaphthalene. A high-yielding ketiminium mediated [2+2]-cycloaddition was also utilized for the simultaneous construction of the remaining three stereocenters.
沙利霉素溴化物是一种抗生素聚酮，先前从海洋严格需氧粘细菌盐沼盐单胞菌中分离得到，其高度官能化和构象刚性的四环骨架在自然界中是前所未有的。在此，我们报告了通过一系列精心协调、稳健的转化首次实现目标结构的化学合成，其中包括酸促进的强 Wagner-Meerwein 重排/Friedel-Crafts 环化序列，以形成嵌入四氢萘中的两个相邻的季碳原子中心。高产率的亚氨基翁介导的[2+2]-环加成也用于同时构建其余三个立体中心。
