In this report, a synthetic study of landomycinone via Masamune–Bergmann cyclization is described. A 10-membered 1,2-dialkynylbenzene derivative was designated as a key intermediate in the formation of an angular tetracyclic core via Masamune–Bergmann cyclization. Cyclization was expected to proceed under mild heating conditions based on a DFT transition state analysis of the 10-membered enediyne.
Reactions of [2-(2-Naphthyl)phenyl]acetylenes and 2-(2-Naphthyl)benzaldehyde<i>O</i>-Phenyloximes: Synthesis of the Angucycline Tetrangulol and 1,10,12-Trimethoxy-8-methylbenzo[<i>c</i>]phenanthridine
作者:Kennedy J. Ngwira、Amanda L. Rousseau、Myron M. Johnson、Charles B. de Koning
DOI:10.1002/ejoc.201601373
日期:2017.3.17
Suzuki-Miyaura coupling reaction between 1,4,5-(trimethoxynaphthalen-2-yl)boronic acid and 2-iodo-3-methoxy-5-methylbenzaldehyde afforded intermediate, 3-methoxy-5-methyl-2-(1,4,5-trimethoxynaphthalen-2-yl)benzaldehyde. Conversion of this benzaldehyde into the alkyne, 2-(2-ethynyl-6-methoxy-4-methylphenyl)-1,4,5-trimethoxynaphthalene was accomplished utilizing the Corey-Fuchs reaction. Exposure of the derived
1,4,5-(三甲氧基萘-2-基)硼酸和2-碘-3-甲氧基-5-甲基苯甲醛之间的铃木-宫浦偶联反应得到中间体3-甲氧基-5-甲基-2-(1, 4,5-三甲氧基萘-2-基)苯甲醛。该苯甲醛转化为炔烃,2-(2-乙炔基-6-甲氧基-4-甲基苯基)-1,4,5-三甲氧基萘是利用 Corey-Fuchs 反应完成的。将衍生的乙炔暴露于催化铂 (II) 介导的闭环产生所需的四环芳烃产物 1,7,8,12-四甲氧基-3-甲基四苯,其转化为四丁醇。将相关的 3-甲氧基-5-甲基-2-(1,4,5-三甲氧基萘-2-基)苯甲醛邻苯基肟在离子液体中暴露于微波辐射下产生 1,10,12-三甲氧基-8-甲基苯并[c]菲啶,
Synthesis of the Benzo[b]fluorene Core of the Kinamycins by Arylalkyne–Allene and Arylalkyne–Alkyne Cycloadditions
作者:Esther González-Cantalapiedra、Óscar de Frutos、Carmen Atienza、Cristina Mateo、Antonio M. Echavarren
DOI:10.1002/ejoc.200500926
日期:2006.3
Arylalkyne–allene and arylalkyne–alkynecycloadditions yields benzo[a]fluorenones, which are related to the tetracyclic core of the kinamycins. In the arylalkyne–alkynecycloadditions, we found a rearrangement that produces benzo[a]fluorenones, in addition to the expected benzo[b]fluorenones. This rearrangement could be suppressed in the presence of phenol, which allowed the synthesis of 4,9-dimet
An approach to the synthesis of the benzo[b]fluorene core of the kinamycins by an arylalkyne-allene cycloaddition
作者:Óscar de Frutos、Antonio M Echavarren
DOI:10.1016/s0040-4039(97)10053-3
日期:1997.11
The cyclization of an3arylalkyne to an allene followed by ring closure was applied for the ready construction of the tetracyclic core of the kinamycin family of antibiotics.
Annulation Strategies for Benzo[<i>b</i>]fluorene Synthesis: Efficient Routes to the Kinafluorenone and WS-5995 Antibiotics
作者:Ghassan Qabaja、Graham B. Jones
DOI:10.1021/jo0056186
日期:2000.10.1
Intramolecular palladium-mediated arylation approaches to benzo[b]fluorenes have been investigated. The methodology has been applied in a short synthesis of tri-O-methylkinafluorenone, providing an effective alternative td Friedel-Crafts-based approaches. During the course of this work, an acid-promoted quinolactonization of naphthoquinones was also developed, providing direct access to either ortho or para isomers as desired. Application of this methodology in syntheses of the antibiotics WS-5995A, WS-5995C, and functional analogues was demonstrated, and antitumoral activity of this class was determined.