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ISBN 9783843902687

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978-3-8439-0268-7, Reihe Organische Chemie

Stephan Andreas Labsch
Stereospezifität der Au(I)-katalysierten Reaktion von 1-Alkinyl-bicyclo[4.1.0]-heptan-2-onen mit Nucleophilen und Studien zur Synthese von Patulin mittels Cyclocarbonylierung

154 Seiten, Dissertation Universität Köln (2011), Softcover, A5

Zusammenfassung / Abstract

The present work contributes to the investigation of the mechanism of the [Au(PPh3)OTf] catalyzed cyclisation of 1-Acyl-1-alkinyl-cyclopropanes with nucleophiles. Based on the synthesis and conversion of enantiomerically enriched substrates the stereospecifity of the mechanism could be revealed. By trying to extend the scope of substrates based on the use of epoxides, imines and hydrazones, a dihydrobenzofurane as well as a cinnolinderivative were obtained. A second project deals with the synthesis of patulin. A sophisticated reaction sequence applying the palladium-catalyzed cyclocarbonylation to build up the bicyclic lactone prepatulin was developed. Further conversion of patulin ought to be performed via oxa-cabene reaction. For this reason, different substrates were synthesized containing a protected propargylic oxa-functionality and an activated acid derivativ. Conversion of these, using literature known cyclocarbonylation conditions smiliar to those in the transformation of structurally related systems, led only to small amounts of the desired bicyclic product. Therefore possibilities to synthesise prepatulin by alternative palladium catalysed and radical pathways were explored, but did not lead to the desired bicyclus.