Total synthesis of brevetoxin B.
Total synthesis of brevetoxin B.
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DOI：
10.1021/ja051171c
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发表时间：
2005-06
影响因子：
15
通讯作者：
I. Kadota;Hiroyoshi Takamura;Hiroki Nishii;Yoshinori Yamamoto
中科院分区：
文献类型：
--
作者：
I. Kadota;Hiroyoshi Takamura;Hiroki Nishii;Yoshinori Yamamoto
实现了短吻蝮蛇毒素B（1）的收敛全合成。使用AgOTf作为刘易斯酸进行由α-氯硫化物17和醇5制备的O，S-缩醛20的分子内烯丙基化，主要得到二烯21。21与Grubbs催化剂23的闭环复分解得到六环醚25，其通过几个步骤转化为A-G环片段2。由2和J-K环片段3制备的α-乙酰氧基醚42的分子内烯丙基化，随后进行闭环复分解，提供了多环醚骨架44。44的一系列反应，包括A环的氧化、甲硅烷基醚的脱保护和所得烯丙醇的选择性氧化，得到1。
The convergent total synthesis of brevetoxin B (1) has been achieved. The intramolecular allylation of the O,S-acetal 20, prepared from the alpha-chlorosulfide 17 and the alcohol 5, was carried out using AgOTf as a Lewis acid to give the diene 21, predominantly. Ring-closing metathesis of 21 with the Grubbs catalyst 23 afforded the hexacyclic ether 25 which was converted to the A-G ring segment 2 through several steps. The intramolecular allylation of the alpha-acetoxy ether 42, prepared from 2 and the J-K ring segment 3, followed by ring-closing metathesis provided the polycyclic ether framework 44. A series of reactions of 44, including oxidation of the A ring, deprotection of the silyl ethers, and selective oxidation of the resulting allylic alcohol, furnished 1.