Prostaglandins in insects and model studies on the paniculides
Prostaglandins in insects and model studies on the paniculides
Extracts of the guts of Acheta domesticus and the haemolymph of Actias perneyi larvae have been analysed for the presence of prostaglandins. Two prostaglandin-like compounds were detected in each extract as the methyl ester, methoxime and trimethylsilyl ether derivatives by gas chromatography. Limited structural information was gained by gas chromatography-mass investigation of these components. The mass spectral data of these derivatives suggested that the components had several trimethylsilyl ether groups, one of which was thought to be primary and another allylic. Derivatisation work in conjunction with gas chromatography on extracts of the haemolymph from Actias perneyi larvae indicated that there was no carbonyl or carboxylic acid group present in these compounds.
Model studies directed towards the design of a total synthesis of (laβ,2aβ,6α,6αβ)-(±)-2,2a,6,6a-tetrahydro-6-hydroxy-la-(hydroxymethyl)-5-(4-methyl-3-pentenyl)oxireno[f]benzofuran-4(laH)-one (paniculide B) and (laβ,2a,6aβ)-(±)-la,2,2a,6a-tetrahydro-la-(hydroxymethyl)-5-(4-methyl-3-pentenyl)oxireno[f]benzofuran-4,6-dione (paniculide C) are described. The basic carbocyclic skeleton for the model system was constructed by reaction of dilithioacetate with trans-2,3-epoxycyclohexan-l-ol which yielded (3aβ,4β,7aβ)-(±)-hexahydro-4-hydroxy-2(3H)-benzofuranone after lactonisation. Two approaches involving the alkylation of 1,3-cyclohexandione with ethyl bromoacetate were found to be unsuitable for the construction of the required skeleton. Further modifications of (3a,4β,7aβ)-(±)-(hexahydro-4-hydroxy-2(3H)-benzofuranone were carried out to introduce an α-hydroxy epoxide moiety onto the cyclohexyl ring. An investigation into the introduction of a latent Δα,β-butenolide olefin via α-phenylthio and α-methylthio ethers was carried out. On the basis of these model studies two synthetic strategies to paniculides B and C are proposed.
The total synthesis of (±)-(6E,10E)-3,7,11,15-tetramethyl-1,6,10,14-hexadecatetraen-3-ol (geranyllinalool) beginning from (6E)-3,7,11-trimethyl-1,6,10-dodecatrien-3-ol (nerolidol), involving a Carroll rearrangement is described. The synthetic material and the natural (R)-(-)-(6E,1OE)-geranyllinalool isolated from the defence secretion of Reticulitermes lucifugus soldiers were found to have identical iH NMR, infrared and mass spectra. Biological testing on the synthetic material indicated that it had insect antifeedant activity and significant insect toxicity.
University of Southampton
Gibson, Colin Leslie
966bfb18-8653-4383-8fd2-3fe342e53859
1983
Gibson, Colin Leslie
966bfb18-8653-4383-8fd2-3fe342e53859
Baker, R
8e65f7f5-ef39-4816-9e9b-b9d31220ee96
Gibson, Colin Leslie
(1983)
Prostaglandins in insects and model studies on the paniculides.
University of Southampton, Doctoral Thesis, 186pp.
Record type:
Thesis
(Doctoral)
Abstract
Extracts of the guts of Acheta domesticus and the haemolymph of Actias perneyi larvae have been analysed for the presence of prostaglandins. Two prostaglandin-like compounds were detected in each extract as the methyl ester, methoxime and trimethylsilyl ether derivatives by gas chromatography. Limited structural information was gained by gas chromatography-mass investigation of these components. The mass spectral data of these derivatives suggested that the components had several trimethylsilyl ether groups, one of which was thought to be primary and another allylic. Derivatisation work in conjunction with gas chromatography on extracts of the haemolymph from Actias perneyi larvae indicated that there was no carbonyl or carboxylic acid group present in these compounds.
Model studies directed towards the design of a total synthesis of (laβ,2aβ,6α,6αβ)-(±)-2,2a,6,6a-tetrahydro-6-hydroxy-la-(hydroxymethyl)-5-(4-methyl-3-pentenyl)oxireno[f]benzofuran-4(laH)-one (paniculide B) and (laβ,2a,6aβ)-(±)-la,2,2a,6a-tetrahydro-la-(hydroxymethyl)-5-(4-methyl-3-pentenyl)oxireno[f]benzofuran-4,6-dione (paniculide C) are described. The basic carbocyclic skeleton for the model system was constructed by reaction of dilithioacetate with trans-2,3-epoxycyclohexan-l-ol which yielded (3aβ,4β,7aβ)-(±)-hexahydro-4-hydroxy-2(3H)-benzofuranone after lactonisation. Two approaches involving the alkylation of 1,3-cyclohexandione with ethyl bromoacetate were found to be unsuitable for the construction of the required skeleton. Further modifications of (3a,4β,7aβ)-(±)-(hexahydro-4-hydroxy-2(3H)-benzofuranone were carried out to introduce an α-hydroxy epoxide moiety onto the cyclohexyl ring. An investigation into the introduction of a latent Δα,β-butenolide olefin via α-phenylthio and α-methylthio ethers was carried out. On the basis of these model studies two synthetic strategies to paniculides B and C are proposed.
The total synthesis of (±)-(6E,10E)-3,7,11,15-tetramethyl-1,6,10,14-hexadecatetraen-3-ol (geranyllinalool) beginning from (6E)-3,7,11-trimethyl-1,6,10-dodecatrien-3-ol (nerolidol), involving a Carroll rearrangement is described. The synthetic material and the natural (R)-(-)-(6E,1OE)-geranyllinalool isolated from the defence secretion of Reticulitermes lucifugus soldiers were found to have identical iH NMR, infrared and mass spectra. Biological testing on the synthetic material indicated that it had insect antifeedant activity and significant insect toxicity.
Text
Gibson 1983 Thesis
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Published date: 1983
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Local EPrints ID: 459775
URI: http://eprints.soton.ac.uk/id/eprint/459775
PURE UUID: b9deef68-5c9c-4210-ae53-8d5faaedb15f
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Date deposited: 04 Jul 2022 17:18
Last modified: 16 Mar 2024 18:33
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Author:
Colin Leslie Gibson
Thesis advisor:
R Baker
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