Cancer Drug Development Group, German Cancer Research Center (DKFZ), Heidelberg, Germany.
Department of Chemistry, School of Science, Tianjin University, Tianjin, China.
Angew Chem Int Ed Engl. 2022 Aug 8;61(32):e202205878. doi: 10.1002/anie.202205878. Epub 2022 Jun 28.
We report asymmetric bioinspired total syntheses of the fungal metabolites emeriones A-C via stereoselective oxidations of two bicyclo[4.2.0]octadiene diastereomers. The central bicyclic scaffolds are prepared in an 8π/6π electrocyclization cascade of a stereodefined pentaene, which contains the fully assembled side chains of the emeriones. The anti-aldol side chain is made using a Paterson-aldol addition, and the epoxide of the dioxabicyclo[3.1.0]hexane side chain via ring-closure onto an oxidized acetal. Our work has enabled the structural revision of emerione C, and resulted in the synthesis of a "missing" family member, which we call emerione D. DFT calculations identified two methyl groups that govern torquoselectivity in the 8π/6π cascade.
我们通过对两种双环[4.2.0]辛二烯非对映异构体的立体选择性氧化,不对称仿生全合成了真菌代谢产物 emeriones A-C。中环骨架是通过立体定义的五烯的 8π/6π 电环化级联反应制备的,其中包含 emeriones 的完全组装的侧链。反-羟醛缩合侧链使用 Paterson-aldol 添加反应构建,而 dioxabicyclo[3.1.0]hexane 侧链的环氧化物则通过闭环到氧化的缩醛上。我们的工作实现了 emerione C 的结构修订,并导致了一个“缺失”家族成员的合成,我们称之为 emerione D。DFT 计算确定了两个甲基,它们控制 8π/6π 级联中的扭转选择性。