Total Syntheses of Juglorescein and Juglocombins A and B
Total Syntheses of Juglorescein and Juglocombins A and B
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DOI：
10.1002/anie.201604765
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发表时间：
2016-08-22
影响因子：
16.6
通讯作者：
Tsubaki, Kazunori
中科院分区：
文献类型：
--
作者：
Kamo, Shogo;Yoshioka, Kai;Tsubaki, Kazunori
本文报道了胡桃木脂素和胡桃木复合物A和B的全合成。这些天然产物的高含氧6/6/5/6/6-稠合五环系统是通过1，4-萘醌的生物启发二聚反应构建的。值得注意的是，五个新的立体异构中心，在一个单一的步骤中构建的二聚反应。通过光诱导的环氧化物的还原、脱水和将所得醌转化为氢醌衍生物，将从二聚获得的环氧化物中间体成功地转化为juglocombins A和B。同样的环氧化物中间体也转化为二羧酸，其通过分子内内酯化、所得内酯的水解和保护基的去除转化为胡桃木脂素。此外，还确定了核桃苷元和核桃组合物A和B的相对构型和绝对构型。
Total syntheses of juglorescein and juglocombins A and B are reported. The highly oxygenated 6/6/5/6/6-fused pentacyclic ring system of these natural products was constructed through a bioinspired dimerization of 1,4-naphthoquinone. Notably, five new stereogenic centers were constructed in a single step by the dimerization reaction. The epoxide intermediate obtained from the dimerization was successfully converted into juglocombins A and B through photoinduced reduction of the epoxide, dehydration, and conversion of the resultant quinone into a hydroquinone derivative. The same epoxide intermediate was also converted into a dicarboxylic acid, which was transformed into juglorescein through intramolecular lactonization, hydrolysis of the resulting lactone, and removal of the protecting groups. Furthermore, the relative and absolute configurations of juglorescein and juglocombins A and B were determined.