A New, Efficient and Stereoselective Synthesis of Tricyclic and Tetracyclic Compounds by Samarium Diiodide Induced Cyclisations of Naphthyl-Substituted Arylketones—An Easy Access to Steroid-Like Skeletons
作者:Francesca Aulenta、Mathias Berndt、Irene Brüdgam、Hans Hartl、Sebastian Sörgel、Hans-Ulrich Reißig
DOI:10.1002/chem.200700057
日期:2007.7.16
we present the application of samarium diiodide induced cyclisations of naphthyl-substituted ketones towards an easy and stereoselective access to tri- and tetracyclic-functionalised compounds. Typical naphthalene derivatives were studied to investigate the scope and limitations of this novel cyclisation process. The model substrates studied demonstrate that the samarium ketyl cyclisations are essentially
在本报告中,我们介绍了由二碘化sa诱导的萘基取代的酮的环化,其对三环和四环官能化化合物的容易和立体选择。对典型的萘衍生物进行了研究,以研究这种新型环化方法的范围和局限性。所研究的模型底物表明,酮基环化基本上仅限于六元环的形成。这些反应的非对映选择性受到烷基侧链与萘核的连接的强烈影响。γ-萘-1-基取代的酮提供环化产物,例如17或22-26,为单一非对映异构体,相反,γ-萘-2-基取代的前体可得到非对映异构体的混合物-如模型化合物10转化为三环产物18a / 18b或环己酮衍生物33转化为四环非对映异构体34a / 34b所证明。作为酮基前体的环状酮提供了类固醇状的四环骨架。然而,由于环B / C和C / D的顺式/顺式融合,这些产物具有“不自然的”碗状形状。X射线分析已鉴定出几种环化产物,不仅证明了结构,而且证明了相对构型和优选构象。类固醇类似物23经历随后的转化,这表明此类化合物的类苯乙