A Short Access to the Skeleton of Elisabethin A and Formal Syntheses of Elisapterosin B and Colombiasin A

Autor: Johann Mulzer, Johannes Preindl, Christian Leitner, Simon Baldauf
Rok vydání: 2014
Předmět:
Zdroj: Organic Letters. 16:4276-4279
ISSN: 1523-7052
1523-7060
DOI: 10.1021/ol501998y
Popis: A short stereoselective synthesis of the Elisabethin A skeleton 4 is described, which opens a formal access to the diterpenes Elisapterosin B and Colombiasin A as well. Key reactions were an intermolecular endo-selective Diels-Alder reaction to generate the decalin part of the molecule, a chemo- and diastereoselective allylation of an aldehyde with allylzinc, a palladium ene annulation of the cyclopentane ring, and a novel sulfonium ylide induced fragmentation of a polycyclic ketone. Additional insights have been gained for the crucial epimerization at C-2.
Databáze: OpenAIRE