A Stereospecific Transannular Diels-Alder Approach to the [6.6.7] Tricyclic Skeleton Related to Aphidicolin and Scopadulan Natural Products

Dennis G. Hall; Alain-Sébastien Caillé; Marc Drouin; Serge Lamothe; Renate Müller; Pierre Deslongchamps

doi:10.1055/s-1995-4077

Synthesis 1995; 1995(9): 1081-1088
DOI: 10.1055/s-1995-4077

paper

© Georg Thieme Verlag, Rüdigerstr. 14, 70469 Stuttgart, Germany. All rights reserved. This journal, including all individual contributions and illustrations published therein, is legally protected by copyright for the duration of the copyright period. Any use, exploitation or commercialization outside the narrow limits set by copyright legislation, without the publisher's consent, is illegal and liable to criminal prosecution. This applies in particular to photostat reproduction, copying, cyclostyling, mimeographing or duplication of any kind, translating, preparation of microfilms, and electronic data processing and storage.

A Stereospecific Transannular Diels-Alder Approach to the [6.6.7] Tricyclic Skeleton Related to Aphidicolin and Scopadulan Natural Products

Dennis G. Hall, Alain-Sébastien Caillé, Marc Drouin, Serge Lamothe, Renate Müller, Pierre Deslongchamps^*

^*Laboratoire de synthèse organique, Département de chimie, Faculté des sciences, Université de Sherbrooke, Sherbrooke, Québec J1K 2R1, Canada, Fax +1(819)8217910; E-mail dlnchamp@structure.chimie.usherb.ca

Abstract

als PDF herunterladen Alle Artikel dieser Rubrik

Model trans-cis-cis (TCC) macrocyclic triene 7 was synthesized using a convergent approach. Upon heating at 200°C, a 1,5-hydrogen-shift on the diene moiety was found to compete with the transannular Diels-Alder (TADA) reaction, thus leading to a mixture of tricyclic products. However, the diene rearrangement could be avoided by using boron trifluoride-diethyl ether complex as catalyst at reduced temperature (60°C). The exclusive formation of the trans-syn-cis [6.6.7] (TSC) tricyclic product 8 through an endo approach was observed. This result demonstrates the feasibility of a TADA strategy for synthesizing the title compounds and analogs.

transannular cycloaddition - Diels-Alder reaction - trans-cis diene - Lewis acid catalysis - trans-syn-cis [6.6.7] skeleton

PDF (856 kb)