Asymmetric Synthesis of Contact Pheromone Component of Xylotrechus colonus and Its Analogues

Xylotrechus colonus is an abundant wood-boring pest of woody plants. 3-Methylpentacosane was identified as the component of its contact pheromone. A novel and efficient asymmetric synthesis of (S)-3-methylpentacosane and its analogues was developed using (S)-2-methylbutan-1-ol as chiral source. The key of this approach included Wittig coupling of chiral phosphonium salt with aldehyde, Pd-catalyzed hydrogenation and Appel reaction. Our synthesis would be helpful for the control and detect of this pest.