Total Synthesis of the Antitumor Antibiotic (±)-Streptonigrin: First- and Second-Generation Routes for de Novo Pyridine Formation Using Ring-Closing Metathesis
作者:Timothy J. Donohoe、Christopher R. Jones、Anne F. Kornahrens、Luiz C. A. Barbosa、Louise J. Walport、Matthew R. Tatton、Michael O’Hagan、Akshat H. Rathi、David B. Baker
DOI:10.1021/jo402388f
日期:2013.12.20
The total synthesis of (±)-streptonigrin, a potent tetracyclic aminoquinoline-5,8-dione antitumor antibiotic that reached phase II clinical trials in the 1970s, is described. Two routes to construct a key pentasubstituted pyridine fragment are depicted, both relying on ring-closing metathesis but differing in the substitution and complexity of the precursor to cyclization. Both routes are short and
描述了 (±)-链黑素的全合成,这是一种有效的四环氨基喹啉-5,8-二酮抗肿瘤抗生素,于 20 世纪 70 年代进入 II 期临床试验。描述了构建关键五取代吡啶片段的两种途径,两者都依赖于闭环复分解,但在环化前体的取代和复杂性方面有所不同。两条路线都很短且产量高,第二代方法最终通过 14 个线性步骤提供 (±)-链黑素,并且从廉价的乙醛酸乙酯中获得 11% 的总产率。这种合成将允许设计和创建类似药物的后期天然产物类似物,以解决药理学限制。此外,在具有挑战性的不对称 Suzuki-Miyaura 交叉偶联反应中对许多手性配体的评估使得首次能够制备对映体富集(高达 42% ee)的合成链黑素中间体。