Catalytic Double Bond Isomerization as a New Way to Valuable Products from Fatty Acids

Fatty acid derivatives provide a useful renewable source for a growing number of functionalized
compounds and fine chemicals. Especially the naturally occuring unsaturated fatty acids hold a
great potential for functionalization and derivatization.[1] Our goal was to realize a new type of
transformation involving a catalytic double bond migration followed by a selective functionalization
reaction. A silver(I)–based catalytic system was found to efficiently promote the double–bond
isomerization of unsaturated fatty acids and to mediate the intramolecular addition of the
carboxylate group to the isomerized double bond under selective formation of five–ring lactones.[2]
These products can be further derivatized to materials bearing special properties, e. g. long–chain
γ–hydroxycarboxylates, –alcohols or –amides.
Expanding this concept from free fatty acids to esters, we have developed a protocol for the direct
conversion of unsaturated aliphatic esters with N-nucleophiles into β-amino esters. We herein want
to introduce our new tandem reaction, which allows the one-step synthesis of β-amino esters via
double–bond isomerization followed by conjugate addition of amines or amides. The products are
valuable intermediates in organic synthesis since they represent direct precursors of ß-lactam
derivatives.
References
[1] M. A. R. Meier, J. O. Metzger, U. S. Schubert, Chem Soc. Rev. 2007, 36, 1788. J. O. Metzger, Eur. J. Lipid Sci.
Technol. 2009, 111, 865.
[2] L. J. Gooßen, D. M. Ohlmann, M. Dierker, Green Chem. 2010, DOI: 10.1039/b916853b.