Asymmetric synthesis of the sex pheromone of the apple leafminer, Lyonetia prunifoliella.

Lyonetia prunifoliella is a significant pest in orchards and damages apple. The sex pheromones of this pest were prepared via a new and concise method. The central to our method were Evans' chiral auxiliaries, the addition of chiral Grignard reagent to aldehyde and Wittig coupling.

Asymmetric syntheses of four stereoisomers of 13-hydroxy-14-methylhexadecanoic acid as potential antibacterial agents.

The first total syntheses of four stereoisomers of 13-hydroxy-14-methylhexadecanoic acid have been accomplished. Central to this strategy are asymmetric alkynylation of aldehyde, acid-catalyzed lactonization, the selective protection of primary alcohol and Wittig reaction. The product 1a was obtained in 17 steps in 2% overall yield. Moreover, these synthetic chiral hydroxy fatty acids 1a-1d are valuable for the development of antibacterial agents.

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.

Cobalt-Bisoxazoline-Catalyzed Enantioselective Cross-Coupling of α-Bromo Esters with Alkenyl Grignard Reagents.

The first catalytic asymmetric Kumada cross-coupling of organic halides with alkenyl Grignard reagents has been developed. The reaction was promoted by the cobalt-bisoxazoline catalyst and afforded various α-alkyl-ß,γ-unsaturated esters with excellent enantioselectivities and moderate to good yields (≤95% ee and ≤82% yields). The formal synthesis of the California red scale pheromone using this method was investigated, and radical clock experiments were performed.