Research progress on the syntheses of aggregation pheromones of flea beetles

Flea beetles are common pests of vegetables, fruits, grains and other crops. The aggregation pheromone components of flea beetles, including fourteen sesquiterpenes and six unsaturated aldehydes, can be used for mass trapping and monitoring. It is a promising technology for control of flea beetles. The syntheses of the sesquiterpenes were described according to the strategies for the construction of chiral center, which consisted of chiral sources, enantioinduction and asymmetric catalytic reactions; whereas the preparations of unsaturated aldehydes were reviewed on basis of the approaches for constructing carbon-carbon double bonds, including aldol condensation, Wittig coupling, Wittig-Horner coupling and acetylenic ester isomerization. Moreover, the advantages and disadvantages of each method were discussed, as well as the prospects for the synthesis of aggregation pheromones of flea beetles.