Institute of Organic Chemistry and Center for Molecular Biosciences, Leopold-Franzens-University Innsbruck, Innrain 80-82, 6020, Innsbruck, Austria.
Institute of General, Inorganic and Theoretical Chemistry, Leopold-Franzens-University Innsbruck, Innrain 80-82, 6020, Innsbruck, Austria.
Angew Chem Int Ed Engl. 2020 Jul 20;59(30):12436-12439. doi: 10.1002/anie.202003127. Epub 2020 Apr 1.
Polyene cyclizations are one of the most powerful and fascinating chemical transformations to rapidly generate molecular complexity. However, cyclizations employing heteroatom-substituted polyenes are rare. Described here is the tetracyclization of a dual nucleophilic aryl enol ether involving an unprecedented transannular endo-termination step. In this transformation, five stereocenters, two of which are quaternary, four carbon-carbon bonds, and four six-membered rings are formed from a readily available cyclization precursor. The realization of this cyclization enabled short synthetic access to the tricyclic diterpenoid pimara-15-en-3α-8α-diol.
聚烯环化反应是一种最强大、最引人入胜的化学转化方法，可快速生成分子复杂性。然而，采用杂原子取代聚烯的环化反应却很少见。本文描述了一种双亲核芳基烯基醚的四环化反应，涉及一个前所未有的跨环内端终止步骤。在这个转化中，从一个易于获得的环化前体中形成了五个立体中心，其中两个是季碳原子，四个碳-碳键和四个六元环。这个环化反应的实现为短程合成三环二萜类化合物扁柏烯-15-烯-3α-8α-二醇提供了可能。
