Syntheses of the Sex-Attractant of Pine Sawfies

Article abstract of DOI:10.1246/bcsj.57.1954

In order to establish the stereochemistry of the sex attractant of various species of pine sawflies, (2S,3R,7R)-, (2S,3R,7S)- and (2S,3S,7S)-2-acetoxy- and 2-propionyloxy-3,7-dimethylpentadecane were synthesized.The alcohol moiety of each pheromone was prepared by the coupling of Grignard reagent of C₁₂ block with tosylate of C₅ block.The C₁₂ block, (R)- and (S)-1-bromo-2-methylundecane, were prepared from (R)-(+)-pulegone.The C₅ block, (2R,3S)- or (2S,3S)-2-methyl-3-tetrahydropyranyloxy-1-(tosyloxy)butane, were derived from (2S,3S)- or (2R,3S)-2-methyl-3-hydroxy butyric acid prepared by the enantio-differentiating hydrogenation of methyl 2-methyl-3-oxobutyrate over the asymmetrically modified nickel catalyst.