%0 Journal Article
%A Weber, Anja
%A Breugst, Martin
%A Pietruszka, Jörg
%T Experimental and Computational Investigations of the Reactions between α,β‐Unsaturated Lactones and 1,3‐Dienes by Cooperative Lewis Acid/Brønsted Acid Catalysis
%J Angewandte Chemie / International edition
%V 59
%N 42
%@ 1521-3773
%C Weinheim
%I Wiley-VCH
%M FZJ-2020-03839
%P 18709 - 18716
%D 2020
%X The reactions of α,β‐unsaturated δ‐lactones with activated dienes such as 1,3‐dimethoxy‐1‐[(trimethylsilyl)oxy]‐1,3‐butadiene (Brassard's diene) are barely known in literature and show high potential for the synthesis of isocoumarin moieties. An in‐depth investigation of this reaction proved a stepwise mechanism via the vinylogous Michael‐products. Subsequent cyclisation and oxidation by LHMDS and DDQ, respectively, provided six mellein derivatives (30–84 %) and four angelicoin derivatives (40–78 %) over three steps. DFT‐calculations provide insights into the reaction mechanism and support the theory of a stepwise reaction.
%F PUB:(DE-HGF)16
%9 Journal Article
%$ pmid:32567075
%U <Go to ISI:>//WOS:000559994400001
%R 10.1002/anie.202008365
%U https://juser.fz-juelich.de/record/885456