Laurefurenynes C–F are four natural products isolated from Laurencia species whose structures were originally determined on the basis of extensive nuclear magnetic resonance experiments. On the basis of a proposed biogenesis, involving a tricyclic oxonium ion as a key intermediate, we have reassigned the structures of these four natural products and synthesized the four reassigned structures using a biomimetic approach demonstrating that they are the actual structures of the natural products. In addition, we have developed a synthesis of the enantiomers of the natural products laurencin and deacetyllaurencin from the enantiomer of (E)-laurefucin using an unusual retrobiomimetic strategy. All of these syntheses have been enabled by the use of tricyclic oxonium ions as pivotal synthetic intermediates.

中文翻译：

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向前和向后 – 使用仿生和逆仿生策略合成 Laurencia 天然产物，并结合月桂脲烯 C–F 的结构重新分配

Laurefurenynes C–F 是从Laurencia物种中分离出来的四种天然产物，其结构最初是根据广泛的核磁共振实验确定的。在所提出的生物发生的基础上，涉及三环氧鎓离子作为关键中间体，我们重新分配了这四种天然产物的结构，并使用仿生方法合成了四种重新分配的结构，证明它们是天然产物的实际结构。此外，我们还利用一种不寻常的逆转录仿生策略，从 ( E )-laurefucin 的对映体合成了天然产物 laurencin 和去乙酰月桂树素的对映体。所有这些合成都是通过使用三环氧鎓离子作为关键的合成中间体来实现的。