The first total synthesis of the Lycopodiumalkaloid (+)-fastigiatine has been accomplished in 15 steps and 30% overall yield from known compounds. Noteworthy transformations include a convergent fragment coupling via a nucleophilic cyclopropane opening, a highly diastereoselective formal [3 + 3]-cycloaddition, and a transannular Mannich reaction to construct the core of the natural product.
Stereoselective Synthesis of 1-Aminocyclopropanecarboxylic Acid Carnosadines via Inter-intramolecular Double Alkylation with Optically Active 2-Methylaziridine Derivatives
作者:Kosuke Ohsawa、Junya Kubota、Shota Ochiai、Takayuki Doi
DOI:10.1021/acs.joc.1c00680
日期:2021.5.21
The stereoselective and short-step synthesis of N-protected allo-carnosadine, ent-carnosadine, and carnosadine lactam was accomplished from a common cyclopropane intermediate. The inter-intramolecular double alkylation of diethyl malonate with an opticallyactive 2-methylaziridine derivative gave the key cyclopropane in excellent yield and optical purity. The following monohydrolysis of the diester
A Unified Strategy for the Synthesis of 7-Membered-Ring-Containing<i>Lycopodium</i>Alkaloids
作者:Amy S. Lee、Brian B. Liau、Matthew D. Shair
DOI:10.1021/ja507740u
日期:2014.9.24
sequence for constructing the common 7-membered-ring core system, followed by either a biomimetic transannular Mannich reaction to access himeradine A (1), lycopecurine (3), and dehydrolycopecurine (4) or an imine reduction for lyconadins A (5) and B (6). This strategy may potentially enable access to all 7-membered-ring-containing Lycopodium alkaloids and provides additional insight into their biosynthetic
石松生物碱天然产物的一个独特子集共享一个 7 元环亚结构,可能来自一个常见的生物合成前体。为了探索和利用这些结构关系,我们寻求开发一种统一的生物合成启发策略,通过使用级联序列有效地获取这些复杂的多环生物碱。为了实现这些目标,(+)-fastigiatine (2) 的首次全合成是通过一系列级联反应完成的;我们在此全面介绍了我们的努力。这些努力的洞察导致了我们合成策略的关键修改,这使得 (-)-himeradine A (1)、(-)-lycopecurine (3) 和 (-)-dehydrolycopecurine (4) 的首次全合成成为可能,如以及 (+)-lyconadin A (5) 和 (-)-lyconadin B (6) 的合成。我们的方法具有非对映选择性的一锅序列,用于构建常见的 7 元环核心系统,然后是仿生跨环曼尼希反应以获取海美拉丁 A (1)、番茄红素 (3) 和脱氢番茄红素