The sex pheromones ofNeodiprion pinetum (Norton) andDiprion similis (Hartig) consist of two isomers, 2S,3S,7S and 2S,3R,7R, in either the acetate orpropionate forms of 3,7-dimethylpentadecan-2-ol, respectively. The 2S,3S,7S acetate isomer is utilized byN. pinetum as the major pheromone component and the 2S,3R,7R acetate as a Synergist. ConverselyD. similis utilizes 2S,3R,7R as propionate the major pheromone component and 2S,3S,7S propionate as a Synergist. This was confirmed in the field in both Michigan and Wisconsin. Capillary gas-liquid chromatographie analyses revealed that these two isomers are present in the natural pheromones of both species at the ratios close to those predicted by artificial blending of the two optical isomers.

The ultrasonic irradiation of Raney nickel catalyst in water followed by the removal of the resulting turbid supernatant gave an excellent nickel catalyst (RNi-U) which generated an asymmetrically-modified nickel catalyst. An EPMA (SEM-EDX) study indicated that RNi-U consisted of a fairly pure nickel surface of homogeneous size. Tartaric acid–NaBr-modified RNi-U (TA–NaBr–MRNi-U) showed a high enantio-differentiating ability as well as reactivity in the hydrogenation of prochiral ketones such as 1,3-diones and 3-oxoalkanoic acid esters.

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 blocks, (R)- and (S)-1-bromo-2-methylundecane, were prepared from (R)-(+)-pulegone. The C5 blocks, (2R,3S)- or (2S,3S)-2-methyl-3-tetrahydropyranyloxy-1-(tosyloxy)butane, were derived from (2S,3S)- or (2R,3S)-2-methyl-3-hydroxybutyric acid prepared by the enantio-differentiating hydrogenation of methyl 2-methyl-3-oxobutyrate over the asymmetrically modified nickle catalyst.

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