Total syntheses of the marine sponge pigments fascaplysin and homofascaplysin B and C
摘要:
The Fascaplysinopsis spp. marine sponge pigments fascaplysin (1), homofascaplysin B (4), and homofascaplysin C (5) have been synthesized by peracid oxidation, reaction with oxalyl chloride/methanol, or Vilsmeier formylation, respectively, of the keystone intermediate 12H-pyrido[1,2-a:3,4-b']diindole (7). The versatile 7 was prepared from indole (17) in six steps (78% yield), a sequence in which the key reaction is the trifluoroacetic acid-induced ring closure of diindole 15, followed by Pd/C-catalyzed dehydrogenation of the crude mixture of cyclized products 25, 26, to give 7 in 93% yield from 15.
Total synthesis of the marine sponge pigment fascaplysin
作者:Benjamin Pelcman、Gordon W Gribble
DOI:10.1016/s0040-4039(00)97367-2
日期:——
Fascaplysin (1), an antimicrobial and cytotoxic red pigmentfrom the marinespongeFascaplysinopsissp., has been synthesized in seven steps from indole (65% yield). The pivotal intermediate in the synthesis is diindole 3 which is induced to undergo acid-catalyzed cyclization and dehydrogenation to afford the desired pentacycle 2 in > 90% yield. Peracid oxidation of 2 yields fascaplysin.
A silver catalyzed and microwave assisted one-pot cascade synthesis provides efficient access to diverse alkaloid-inspired scaffold classes, and a concise and efficient total synthesis of homofascaplysin C and fascaplysin.
A new method for the synthesis of the marine alkaloid fascaplysin
作者:Maxim E. Zhidkov、Olga V. Baranova、Natalya S. Kravchenko、Sergey V. Dubovitskii
DOI:10.1016/j.tetlet.2010.09.120
日期:2010.12
A new method for the synthesis of the marine alkaloid fascaplysin has been developed via a simple and practical approach to pyrido[1,2-a:3,4-b′]diindole ring system formation. Conversion of the marine alkaloid homofascaplysinC into fascaplysin is also described.
通过简单实用的方法,开发了吡啶并[1,2- a:3,4- b ']二吲哚环系统形成的新方法,用于合成海洋生物碱法丝溶素。还描述了将海洋生物碱高法丝溶素C转化为法丝溶素。
A pyrone remodeling strategy to access diverse heterocycles: application to the synthesis of fascaplysin natural products
作者:Vignesh Palani、Melecio A. Perea、Kristen E. Gardner、Richmond Sarpong
DOI:10.1039/d0sc06317g
日期:——
The synthesis of diverse N-fused heterocycles, including the pyrido[1,2-a]indole scaffold, using an efficient pyrone remodeling strategy is described. The pyrido[1,2-a]indole core was demonstrated to be a versatile scaffold that can be site-selectively functionalized. The utility of this novel annulation strategy was showcased in a concise formal synthesis of three fascaplysin congeners.
描述了使用有效的吡喃酮重塑策略合成各种N稠合杂环,包括吡啶并[1,2- a ] 吲哚支架。吡啶并[1,2- a ]吲哚核心被证明是一种多功能支架,可以进行位点选择性功能化。这种新颖的成环策略的实用性在三种 fascaplysin 同源物的简明正式合成中得到了展示。
PELCMAN, BENJAMIN;GRIBBLE, GORDON W., TETRAHEDRON LETT., 31,(1990) N7, C. 2381-2384