Pheromone synthesis. Part 256: Synthesis of the four stereoisomers of 5,11-dimethylpentacosane, a new sex pheromone component of the male Galleria mellonella (L.), with high stereochemical purities as determined by the derivatization-HPLC analysis of the eight stereoisomers of 5,11-dimethyl-8-pentacosanol

Total Synthesis of the Sex Pheromone of Clania variegata Snellen and Its Stereoisomers

The paulownia bagworm, Clania variegata Snell, is an economically important pest of agriculture and forests. The sex pheromone of this pest and its stereoisomers were synthesized, and two of the stereoisomers were prepared for the first time. Our strategy was efficient and mainly included the ring-opening reaction of (S)-2-methyloxirane, the coupling of chiral sulfonate, the oxidative cleavage of olefin, and Yamaguchi esterification. Moreover, the overall yields of our synthesis were 23-29%, with eight steps in the longest route.

Recent advances in the synthesis of insect pheromones: an overview from 2013 to 2022

Covering: 2013 to June 2022Pheromones are usually produced by insects in sub-microgram amounts, which prevents the elucidation of their structures by nuclear magnetic resonance (NMR). Instead, a synthetic reference material is needed to confirm the structure of the natural compounds. In addition, the provision of synthetic pheromones enables large-scale field trials for the development of environmentally friendly pest management tools. Because of these potential applications in pest control, insect pheromones are attractive targets for the development of synthetic procedures and the synthesis of these intraspecific chemical messengers has been at the core of numerous research efforts in the field of pheromone chemistry. The present review is a quick reference guide for the syntheses of insect pheromones published from 2013 to mid-2022, listing the synthesized compounds and highlighting current methodologies in organic synthesis, such as carbon-carbon coupling reactions, organo-transition metal chemistry including ring-closing olefin metathesis, asymmetric epoxidations and dihydroxylations, and enzymatic reactions.

Total synthesis of four stereoisomers of methyl 4,8,12-trimethylpentadecanoate, a major component of the sex pheromone of the stink bug Edessa meditabunda

The male-produced sex pheromone of the stink bug Edessa meditabunda was previously identified as a mixture of the esters methyl 4,8,12-trimethylpentadecanoate (1) and methyl 4,8,12-trimethyltetradecanoate (2), produced in a ratio of 92 : 8, respectively. Bioassays showed that the synthetic major compound alone is sufficient to elicit a response from females, and that it is as attractive as the natural extract. Here we present a stereoselective synthesis of four stereoisomers of methyl 4,8,12-trimethylpentadecanoate. The synthetic route was based on the connection of three chiral building blocks. High stereoisomeric purity was achieved by using commercially available compounds with defined stereochemistry, (R) and (S)-citronellol and methyl (S)-3-hydroxy-2-methylpropionate. Different stereoisomers were synthesized by swapping the sequence in which the building blocks were inserted into the synthetic route. The key steps in the synthesis were coupling reactions using the Fouquet-Schlosser variant of the Grignard reaction. Although the absolute configuration of the natural product remained elusive due to chromatographic inseparability of the stereoisomers, the syntheses gave access to both enantiomers of the biosynthetically most likely stereoisomer syn,syn-1, while all other stereoisomers can be efficiently synthesized by our straightforward approach.