Investigação da reatividade da rotundifolona isolada de Lippia pedunculosa Hayek frente às reações de Diels-Alder e de Wittig

Abstract

Rotundifolone is a monoterpene biosynthetically derived from piperitenone, found in species of the genus Mentha and known for several biological activities. It is extracted with high yield from the essential oil of Lippia pedunculosa leaves and identified as the major constituent of the essential oil. Although widely studied in relation to its biological activities, there is little published material on chemical transformations on its structure. This work aimed to carry out chemical transformations using rotundifolone as starting material, specifically through pericyclic carbon-carbon bond formation reactions, such as Diels-Alder and Wittig reactions. The essential oil and the other products of this work were separated and purified by preparative thin layer chromatography and analyzed by nuclear magnetic resonance spectroscopy. Rotundifolone was isolated in good yield from L. pedunculosa oil. The Diels-Alder and Wittig reactions did not generate the expected products, and only the BF3 catalyzed hetero-Diels-Alder reaction consumed the starting material, resulting in a complex mixture of products that remains under investigation. We speculate that the low reactivity of rotundifolone to these methods could be due to sterical and/or experimental issues.