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Synlett 2005(15): 2379-2381  
DOI: 10.1055/s-2005-872261
LETTER
© Georg Thieme Verlag Stuttgart · New York

Towards the Synthesis of Paulitin: New Insights into the Enyne-Metathesis Mechanism

Emeline Vedrenne, Frédérique Royer, Julie Oble, Laurent El Kaïm, Laurence Grimaud*
Laboratoire Chimie et Procédés, Ecole Nationale Supérieure de Techniques Avancées, 32 Bd Victor, 75739 Paris Cedex 15, France
Fax: +33(1)45528322; e-Mail: laurence.grimaud@ensta.fr;
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Publication History

Received 9 June 2005
Publication Date:
03 August 2005 (online)

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Abstract

In our approach towards Paulitin, a sesquiterpene lactone, we have shown that steric hindrance at the propargylic position is of importance to the outcome of enyne metathesis. Moreover, we have uncovered further evidence to confirm that the alkyne-first pathway should be the favored process in enyne metathesis.

Key words

metathesis - alkyne - steric hindrance - 1,3-dienes - ­mechanism

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7

According to NMR spectra, regioisomer 2 seemed to be isolated as one single stereoisomer whose configuration was not determined.