Isomerization of Anacardic Acid: A Possible Route to the Synthesis of an Unsaturated Benzolactone and a Kairomone

Abstract
Crystalline unsaturated lactone, 8-hydroxy-3-tridecyl-1H-isochromen-1-one (6) has been synthesized by isomerization of anacardic acid having heterogeneous alkyl side chains (a mixture of mono-, di-, and tri-unsaturated anacardic acid) (1). Hydrogenation of 8-hydroxy-3-tridecyl-1H-isochromen-1-one produced a saturated lactone, 8-hydroxy-3-tridecyl-3,4-dihydroisochromen-1-one (7). Isomerization of monoene anacardic acid resulted in a crystalline isoanacardic acid, (E)-2-hydroxy-6-(pentadec-1-enyl)benzoic acid (8) as a major product. This was then metathesized with 2-butene to give 3-prop-1-enylphenol (10). Both isomerization reactions used a 1,2-bis(ditertiarybutylphosphinomethyl)benzene modified palladium catalyst. The two products, 8-hydroxy-3-tridecyl-1H-isochromen-1-one and (E)-2-hydroxy-6-(pentadec-1-enyl)benzoic acid have been crystallographically characterized.
Description
Full text can be accessed at http://onlinelibrary.wiley.com/doi/10.1002/ejlt.201400268/full
Keywords
Anacardic acid, Benzolactone, Double bond isomerisation, Isoanacardic acid, Kairomone
Citation
Mgaya, J.E., Mubofu, E.B., Mgani, Q.A., Cordes, D.B., Slawin, A.M. and Coleā€Hamilton, D.J., 2015. Isomerization of anacardic acid: A possible route to the synthesis of an unsaturated benzolactone and a kairomone. European Journal of Lipid Science and Technology, 117(2), pp.190-199.