Novel Cuticular Hydrocarbons from the Cane Beetle Antitrogus parvulus4,6,8,10,16-Penta- and 4,6,8,10,16,18-HexamethyldocosanesUnprecedented anti-anti-anti-Stereochemistry in the 4,6,8,10-Methyltetrad

Abstract

The major cuticular hydrocarbons from the cane beetle species Antitrogus parvulus are 4,6,8,10,16-penta- and 4,6,8,10,16,18-hexamethyldocosanes, 1 and 2, respectively. Stereoisomers of 2,4,6,8-tetramethylundecanal of established relative stereochemistry were derived from 2,4,6-trimethylphenol and were then coupled with appropriate methyl-substituted phosphoranes 62 and 25 to furnish alkenes, which on reduction provided diastereomers of 1 and 2, respectively. Capillary gas chromatography, mass spectrometry, and high resolution 13C NMR spectroscopy confirmed 1 as either 84a or 84b and 2 as either 15a or 15b. The novelty of these structures and their relative stereochemistry is briefly related to polyketide assembly.

Structure elucidation of female-specific volatiles released by the parasitoid wasp Trichogramma turkestanica (Hymenoptera: Trichogrammatidae)

“…2), 21 was chain-elongated to a 1:3-mixture of (2 E ,4 Z )- syn , syn - and (2 E ,4 E )- syn , syn -4,6,8,10-tetramethyltrideca-2,4-diene ( 22 ). The stereochemical composition of this defined mixture of stereoisomers of 15 (see Supporting Information File 1, Figure S2) was assigned by NMR spectroscopy, matching respective data reported in the literature [21–22]. …”

Diverse cuticular hydrocarbons from Australian canebeetles (Coleoptera: Scarabaeidae)

“…2003). The stereochemistry of the 4,6,8,10,16‐penta‐ and 4,6,8,10,16,18‐hexamethyldocosanes ( 6 ) and ( 7 ) was established by comparisons of mass spectra, high‐resolution nuclear magnetic resonance spectroscopy and chromatographic properties of various synthetic samples and natural hydrocarbons – both have an anti‐anti‐anti stereochemistry of the methyl tetrad moiety, and a syn methyl diad at the other end of the hexamethyldocosane (Chow et al . 2005; Herber & Breit 2005; Zhou et al .…”

“…(1999, 2001, 2003), McGrath et al . (2003), Chow et al . (2005), Herber and Breit (2005), Zhou et al .…”

Making Mixtures to Solve Structures: Structural Elucidation via Combinatorial Synthesis

“…Synthetic Strategy. The total or partial synthesis of polypropylene oligomers 35,36 and natural products [37][38][39][40][41][42] containing C 3 repeat units like those in the target molecules has been reported previously. While natural products might be suitable precursors to series 3, 5, and 6, they are not readily amenable to the synthesis of the other target compounds; accordingly we opted for total synthesis.…”