Unsaturated Macrocyclic Compounds. XXI.1The Synthesis of a Series of Fully Conjugated Macrocyclic Polyene-polyynes (Dehydro-annulenes) from 1,5-Hexadiyne
Starting from small cyclic ketones, continuous flow synthesis is used to produce medium-sized rings and macrocycles that are relevant for the fragrance industry. Triperoxides are important intermediates in this process and are pyrolyzed at temperatures above 250 °C. The synthesis is carried out in two continuously operated flow reactors connected by a membrane-operated separator. The practicality of
从小环酮开始,连续流动合成用于生产与香料工业相关的中型环和大环。三过氧化物是该过程中的重要中间体,可在 250 °C 以上的温度下热解。合成是在两个连续操作的流动反应器中进行的,这些反应器由膜操作的分离器连接。在这项工作中,通过使用危险的试剂混合物(30% H 2 O 2、65% HNO 3)和同样有问题的过氧化物的热解,令人印象深刻地证明了流动化学的实用性。所有新的大环化合物都进行了与麝香相关的嗅觉特性测试。
Eine einfache Synthese makrocyclischer Kohlenwasserstoffe durch Metathese von Cycloolefinen
作者:Siegfried Warwel、Hans Kätker
DOI:10.1055/s-1987-28129
日期:——
A Simple Synthesis of Macrocyclic Hydrocarbons by Metathesis of Cycloolefins Metathesis of cycloolefins normally leads to unsaturated polymers. Using rheniumheptoxide on alumina, activated by tintetramethyl and working in dilution via soxhlet-similiar circulation system the metathesis reaction was directed to macrocyclic dienes, which are the dimers of the initial cycloolefins. Starting with C7-, C9- and C10-cycloolefins symmetric macrocyclic C14-, C18- and C20-dienes are obtained in yields of 58-74%. The metathetic dimerization of cyclooctene leads to 1.9-cyclohexadecadiene in a yield of 30%. By hydrogenation at room temperature and normal hydrogen-pressure all cyclodienes were converted quantitatively to cycloalkenes (catalyst: potassium on alumina) or to cycloalkenes (catalyst: palladium on carbon).
Cyclooctane Metathesis Catalyzed by Silica-Supported Tungsten Pentamethyl [(SiO)W(Me)<sub>5</sub>]: Distribution of Macrocyclic Alkanes
作者:Nassima Riache、Emmanuel Callens、Manoja K. Samantaray、Najeh M. Kharbatia、Muhammad Atiqullah、Jean-Marie Basset
DOI:10.1002/chem.201403704
日期:2014.11.10
Metathesis of cyclic alkanes catalyzed by the new surface complex [(SiO)W(Me)5] affords a wide distribution of cyclic and macrocyclic alkanes. The major products with the formula CnH2n are the result of either a ringcontraction or ringexpansion of cyclooctane leading to lower unsubstituted cyclic alkanes (5≤n≤7) and to an unprecedented distribution of unsubstituted macrocyclic alkanes (12≤n≤40)