Synthesis of the enantiomers of 13-methylheptacosane, the sex pheromone of pear psylla, Cacopsylla pyricola.

An efficient and gram-scale enantioselective synthesis of (R)- and (S)-13-methylheptacosane, the sex pheromone of pear psylla, has been developed. The key steps of the approach included Evans' chiral auxiliaries and Wittig coupling of chiral phosphonium salt with aldehyde.