A New Asymmetric Synthesis of (S)-14-Methyloctadec-1-ene, the Sex Pheromone of the Peach Leafminer Moth

An asymmetric synthesis of 14-methyl-1-octadecene, the sex pheromone of the peach leafminer moth has been achieved. Based on the asymmetric methylation of chiral (S)-4-benzyloxazolidin-2-one, the carbon chain of the target molecule was assembled through a C1+C10+C4+C3 procedure. The γ-lactone was transformed into 4-(benzyloxy)butanoic acid and then, with the induction of Evan’s template, a chiral methyl group was introduced to the position of the carboxylic group in 97% de. After reduction and a couple of chemical operations, the designed key intermediate A1 was obtained. The synthesis of another moiety was started from decane-1,10-diol which was selectively protected and oxidized. The long carbon chain was installed according to a Wittig protocol. After deprotection, oxidization, and methylenation, the target molecule was synthesized in 7 linear steps with an overall yield of 30.3%.