Unprecedented influence of remote substituents on reactivity and stereoselectivity in Cu(i)-catalysed [2 + 2] photocycloaddition. An approach towards the synthesis of tricycloclavulone
作者:Sujit Mondal、Ram Naresh Yadav、Subrata Ghosh
DOI:10.1039/c1ob05233k
日期:——
Cu(I)-catalysed [2 + 2] photocycloaddition of 1,6-dienes embedded in a furano sugar is described in connection to a synthetic approach to an abnormal marine prostanoid tricycloclavulone. An unprecedented influence of remote substituents on the reactivity and stereoselectivity of the photocycloaddition reaction has been uncovered during this investigation. While an alkene substituent inhibits cycloaddition through steric effects, a substituent having a hydroxyl or alkoxy group at the same location facilitates cycloaddition exclusively from its own side. This investigation has led to the synthesis of a functionalised 5,4-fused core unit of tricycloclavulone.
本研究介绍了 Cu(I)-Catalysed [2 + 2] photocycloaddition of 1,6-dienes embedded in a furano sugar(呋喃糖内嵌的 1,6-二烯的光环加成反应)与异常海洋前列腺素三环黄酮的合成方法。在这项研究中,发现了偏远取代基对光环加成反应的反应性和立体选择性的前所未有的影响。烯基取代基通过立体效应抑制环化反应,而在同一位置具有羟基或烷氧基的取代基则完全从其自身一侧促进环化反应。通过这项研究,我们合成了三环黄酮的功能化 5,4-融合核心单元。