Studies on the Syntheses of Spilanthol. V

N-Isobutyl-cis-4, trans-6-decadienamide and the Structure of Spilanthol

Abstract

Condensation of 1-bromo-2-hexene and ethyl 3-formylpropionate by the Reformatsky reaction afforded ethyl 4-hydroxy-trans-6-decenoate, whose methyl ester was reacted with N-isobutylamine to form the amide. Its dehydration and column chromatography through alumina layer to remove trans-4, trans-6-decadienamide, with ultraviolet absorption maxima of 225 and 270mμ (petr. ether, b.p. 60°) as the criteria, afforded the objective. The infrared absorption spectrum of this amide was similar to that of natural spilanthol from Spilanthes oleracea JACQ., but there were some shifts and the synthesized amide had only weak acid taste and paralytic action.