Application of allylic substitutions in natural products synthesis
G. Helmchen, M. Ernst, and G. Paradies
Organisch-Chemisches Institut der Universität
Heidelberg, Im Neuenheimer Feld 270, D-69120 Heidelberg, Germany
Abstract: Synthesis routes are described, allowing all known
jasmonoids as well as their enantiomers to be synthesized in enantiomerically
and diastereomerically pure form. The routes are based on a set of closely
related lactones containing an electrophilic allylic moiety, which are
accessible via asymmetric Pd-catalyzed allylic alkylation. Regio- and
diastereoselective SN2'-anti-reactions of the electrophilic
lactones with organocopper compounds furnished 2,3-cis-disubstituted
cyclopentenones, which were further transformed into the target compounds,
i.e., 12-oxophytodienoic acid (12-OPDA) in excellent overall yields.
The methodology also allowed iridoids and isoprostanes to be prepared.
The configuration of an Archaea membrane lipid constituent containing
cyclopentane rings was determined by total synthesis of a diol that
was also obtained by degradation of the natural product.
*Plenary and invited lectures presented at the 12th International Symposium on Organometallic Chemistry Directed Towards Organic Synthesis (OMCOS-12), Toronto, Ontario, Canada, 6-10 July 2003. Other lectures are published in this issue, pp. 453-695.
Page last modified 20 May 2004.
Copyright © 2004 International Union of Pure and Applied Chemistry.
Questions or comments about IUPAC, please contact, the Secretariat.
Questions regarding the website, please contact web
manager.