From Phenols to Azulenes: An Extended and Versatile Route to Polyalkylated Azulenes with Variable Substitution Patterns at the Seven- and Five-membered Ring
作者:Matthias Nagel、Hans-Jürgen Hansen
DOI:10.1055/s-2002-25363
日期:——
Polyalkylated azulenes can easily be prepared from polyalkylphenyl propiolates which are transformed by dynamic gas phase thermo-isomerization (DGPTI) into polyalkylcyclohepta[b]furan-2(2H)-ones. The latter react thermally with enol ethers or enamines to the corresponding azulenes. The enamines may be generated in situ from corresponding aminals, especially, in cases where it is difficult to obtain the pure enamines due to their high reactivity.
通过动态气相热异构化(DGPTI)将多烷基苯基丙醇酸酯转化为多烷基环庚基[b]呋喃-2(2H)-酮,可以轻松制备多烷基化偶氮烯。后者与烯醇醚或烯胺发生热反应,生成相应的偶氮烯。烯胺可由相应的酰胺类物质就地生成,尤其是在由于烯胺的高反应性而难以获得纯烯胺的情况下。