Syntheses of the Sixteen Stereoisomers of 3,7,11-Trimethyl-2-tridecanol, Including the (2S,3S,7S,11R) and (2S,3S,7S,11S) Stereoisomers Identified as Pheromone Precursors in Females of the Pine Sawfly Microdiprion pallipes (Hymenoptera: Diprionidae)

Abstract

All sixteen stereoisomers of 3,7,11‐trimethyl‐2‐tridecanol were synthesised in high stereoisomerical purities (> 95%), for use in the identification of the stereoisomers present in females of the pine sawfly Microdiprion pallipes (Fallén) (Hymenoptera: Diprionidae) as the precursor of the actual sex pheromone (which is the propionate), and also for investigation of the biological activities of the esters. The key step in the syntheses was the coupling of each of the enantiomers of cis‐3,4‐dimethyl‐γ‐butyrolactone with each of the four pure stereoisomers of 1‐lithio‐2,6‐dimethyloctanes. The four corresponding alcohols were obtained by lipase‐catalysed (Amano PS) kinetic separation, based on selective acylation of either (2R/S,6S)‐ or (2R/S,6R)‐2,6‐dimethyl‐1‐octanol (obtained from the optically pure enantiomers of citronellal). Additionally, a mixture of the 16 possible stereoisomers of 3,7,11‐trimethyl‐2‐tridecanol was also prepared.

Synthesis of the Insect Pheromone (2S,3S,7RS)-Diprionyl Acetate by Diastereoselective Protonation

“…The method can also be applied to the synthesis of other stereoisomers of 1 since carvone (3) is readily available in both enantiomeric forms; likewise, insect pheromones with branched or shorter chains [15] are accessible by reacting lactone (S,S)-8 with the appropriate organolithium reagent.…”

Behavioral and Electrophysiological Responses of Triatoma brasiliensis Males to Volatiles Produced in the Metasternal Glands of Females

“…After purification by chromatography a fraction of 99% purity (257 mg, 99% enantiomeric purity) was obtained. Spectroscopic data correlated well with literature data (NIST 2002;Larsson et al 2001). …”

Stereoisomer libraries: Total synthesis of all 16 stereoisomers of the pine sawfly sex pheromone by a fluorous mixture-synthesis approach

“…Spectral data ( 1 H and 13 C NMR) obtained for all 32 compounds (16 alcohols 15 and the corresponding propionates 1) matched well with the data of Hedenström and coworkers (10), thereby validating the f luorous-tag encoding of diastereoisomers. This method is recommended for the efficient synthesis of multiple stereoisomers for spectroscopic studies, biological tests, or other structure-function relationships.…”

“…The NMR spectral data ( 1 H and 13 C) for all 16 isomers of alcohols 15 and propionates 1 matched well with the data of Hedenström and coworkers (10), which then confirms that the encoding͞decoding strategy worked as planned. We also were able to identify unique fingerprint resonances in the 1 H NMR spectra (600 MHz) of the eight diastereomeric alcohols of 15.…”

“…SSSR-1 and all pheromone structures in this article are presented with the backbone in the plane of the page such that when any chain substituent (Me or OH) is above the plane, the absolute configuration of its stereocenter is R, and when any chain substituent is below the plane, the absolute configuration of its stereocenter is S. We report herein the asymmetric syntheses of all 16 stereoisomers of 1 by a strategy that combines FMS with splitting. Successful decoding of all 16 isomers was validated by comparison with the published data of Hedenström and coworkers (10). Substantial amounts (10-20 mg) of each of the final products have been produced.…”