Insect chemistry and chirality

Abstract

Examination of the chemistry of a number of Australian insect species provided examples of unusual structures and encouraged determinations of their absolute stereochemistry by stereocontrolled syntheses and chromatographic comparisons. Inter alia, studies with the fruit-spotting bug (Amblypelta nitida), certain parasitic wasps (Biosteres sp.), the aposematic shield bug (Cantao parentum), and various species of scarab grubs are summarized. The determination of enantiomeric excesses (ee's) for component epoxides, lactones, spiroacetals, and allenes are described. Stereochemical and related aspects of the biosynthesis of spiroacetals in certain fruit-fly species (Bactrocerae sp.) are also presented.

Intrageneric differences in the four stereoisomers of stenusine in the rove beetle genus, Stenus (Coleoptera, Staphylinidae)

“…The study on nonpheromones is justified particularly for chemotaxonomic reasons (Hayes et al 2003). Stenusine appears in most Stenus species and can be seen as a monophyletic character.…”

Essential oil of Plectranthus tenuicaulis for flavour and fragrance: Synthesis of derivatives from natural and synthetic 6,7‐epoxyocimenes

“…Among them, four were described for the first time; in most of the other cases, the spectral data were not fully described previously and are detailed here; finally, the gas chromatographic retention data of all compounds were determined on two stationary phases with distinct polarities; it would be useful for their detection in natural volatile extracts. Interestingly, (R)-(E)-6,7-epoxyocimene was identified as a pheromone involved in the chemical communication of the fruit-spotting bug Amblypelta nitida; [31] therefore, besides its chemical valorization in synthesizing volatile compounds of interest in the flavour and fragrances field, the essential oil of Plectranthus tenuicaulis could find applications in crop protection programmes.…”

“…Interestingly, ( R )‐( E )‐6,7‐epoxyocimene was identified as a pheromone involved in the chemical communication of the fruit‐spotting bug Amblypelta nitida ; therefore, besides its chemical valorization in synthesizing volatile compounds of interest in the flavour and fragrances field, the essential oil of Plectranthus tenuicaulis could find applications in crop protection programmes.…”

[(2S,3aR,6aR)-5-Oxohexahydrofuro[3,2-b]furan-2-yl]methyl acetate

“…For the stereoselective synthesis, applications and structures of related 2,6-dioxabicyclo[3.3.0]octan-3-ones, see: Agrawal et al (2006); Banda & Chakravarthy (2006); Paddon-Jones et al (2001). For the biological activity of target compounds, see: Hayes et al (2003). For the synthesis of chiral tetrahydrofurans using l-malic acid, see: Á lvarez et al (2010).…”