Rapid and Stereoselective Synthesis of Spirocyclic Ethers via the Intramolecular Piancatelli Rearrangement
作者:Leoni I. Palmer、Javier Read de Alaniz
DOI:10.1021/ol303263q
日期:2013.2.1
The first example of a Piancatelli rearrangement of alcohols is demonstrated utilizing dysprosium(III) triflate as a catalyst to access oxaspirocycles in a highly diastereoselective manner. The cascade reaction constructs the spirocyclicether ring system and the tertiary stereocenter in a single operation and is experimentally easy to perform.
Direct synthesis of oxaspirolactones in batch, photoflow, and silica gel-supported solvent-free conditions <i>via</i> visible-light photo- and heterogeneous Brønsted acid relay catalysis
quantitative yields and broad scope while only using green solvents and an energy-saving light source. In addition, translation of the developed method into photoflow and chromatography-grade silicagel-supported solvent-free conditions demonstrates good scalability and simplification of the reaction process. The latter procedure was further shown to be amenable to sunlight and air as natural sources
通过融合能量转移可见光光催化和非均相布朗斯台德酸催化,描述了一种操作简单的氧螺内酯合成方法,氧螺内酯是存在于许多具有治疗特性的分子中的天然支架。单线态氧 ( 1 O 2 ) 的顺序光氧化) 和酸促进的甲硅烷基化羟烷基呋喃缩酮化反应以定量产率和广泛的范围提供目标化合物,同时仅使用绿色溶剂和节能光源。此外,将开发的方法转化为光流和色谱级硅胶支持的无溶剂条件证明了良好的可扩展性和反应过程的简化。后一种方法被进一步证明可以接受阳光和空气作为自然光和分子氧的来源,这是反应所必需的。还提出了初步对照研究,以进一步阐明所研究的转化机制。此外,对已建立协议的 EcoScale 和绿色指标进行了评估,以针对文献中报告的一些方法进行基准测试。
Kasiwagi, Bulletin of the Chemical Society of Japan, 1927, vol. 2, p. 317
作者:Kasiwagi
DOI:——
日期:——
Meier, Lothar; Scharf, Hans-Dieter, Liebigs Annalen der Chemie, 1986, # 4, p. 731 - 740
作者:Meier, Lothar、Scharf, Hans-Dieter
DOI:——
日期:——
Tandem Achmatowicz Rearrangement and Acetalization of 1-[5-(Hydroxyalkyl)-furan-2-yl]-cyclobutanols Leading to Dispiroacetals and Subsequent Ring-Expansion to Form 6,7-Dihydrobenzofuran-4(5<i>H</i>)-ones
作者:Hui Peng、Wenkun Luo、Huanfeng Jiang、Biaolin Yin
DOI:10.1021/acs.joc.8b01765
日期:2018.10.19
dispiroacetals 4 bearing a cyclobutane motif via tandem Achmatowiczrearrangement and acetalization of 1-[5-(hydroxyalkyl)-furan-2-yl]-cyclobutanols 3 with m-CPBA as the oxidant and AgSbF6 as an additive to promote the cyclization step in an aqueous medium. Dispiroacetals 4 could subsequently undergo Lewis acid-catalyzed ring expansion and skeletal rearrangement to afford 6,7-dihydro-5H-benzofuran-4-ones 5.
在此,我们报告dispiroacetals合成的单罐协议4经由串联Achmatowicz重排和1- [5-(羟烷基) -呋喃-2-基]的缩醛轴承环丁烷基序-cyclobutanols 3与米-CPBA作为氧化剂和AgSbF 6作为添加剂,以促进在水性介质中的环化步骤。二螺缩醛4随后可以进行路易斯酸催化的环扩展和骨架重排,以提供6,7-dihydro-5 H -benzofuran-4-ones 5。