Identification of the sex pheromone of Nezara viridula (L.) and synthesic studies towards ephedradines A-D
Identification of the sex pheromone of Nezara viridula (L.) and synthesic studies towards ephedradines A-D
The isolation of the sex pheromones from two populations of Nezara viridula (L.) is described. The sex pheromone produced by male N. viridula (L.), from France, was shown to comprise a 2:1 mixture of (Z)-2-[(1R*,3S*,4R*)-3,4-epoxy-4-methylcyclohexyl]-6-methyl-2,5-heptadiene and (Z)-2-[1R*,3R*,4S*)-3,4-epoxy-4-methylcyclohexyl]-6-methyl-2,5-heptadiene. The male sex pheronone from the Brazilian population was shown to be the single sesquiterpene, (Z)-(-)-2-[(1S,3R,4S)-3,4-epoxy-4-methylcyclohexyl]-6-methyl-2,5-heptadiene. The synthesis of all eight (E/Z)-2-(3,4-epoxy-4-methylcyclohexyl)-6-methyl-2,5-heptadiene isomers is described. Approaches towards 2-aryl-5-formyl-3-methoxy-carbonyl-2,3-dihydro-benzo[b]furans via hexahydro-benzo[b]furan intermediates have been investigated. A general procedure for the preparation of t -2-aryl-5-formyl-3-methoxy-carbonyl-2,3-dihydro-benzo[b]furans by the cyclisation of methyl 2-[2-benzyloxy-5-(dimethoxy-methyl)-phenyl]-3-aryl-3-hydroxypropionate derivatives has been developed. Model studies towards the enantioselective synthesis of the dihyrod-benzo[b]furan moieties of ephedradines A-D are described. Thus, (4R)-(+)-3-[(2R,3R)-2-(2-benzyloxyphenyl)-3-(4-benzyloxyphenyl)-3-hydroxy-1-oxopropyl]-4-isopropyl-2-oxazolidinone (165) was cyclised to give (4R)-(-)-3-[(2R,3R)-2-(4-hydroxyphenyl)-2,3-dihydro-benzo[b]furan-3-ylcarbonyl]-4-isopropyl-R)-(-)-3-[(2R,3R)-2-(4-hydroxyphenyl)-2,3-dihydro-benzo[b]furan-3-ylcarbonyl]-4-isopropyl-2-oxaxolidi Conditions for the condensation ofdro-benzo[b]furan-3-ylcarbonyl]-4-isopropyl-2-oxaxolidinone (166). Conditions for the condensation of boron enolates of thioesters with imines were developed. N-(tert-Butoxycarbonyl)-9-[2R*,3R*)-2-(3,4-dimethoxyphenyl)-5-formyl-2,3-dihydrobenzo[b]furan-3-yl-carbonyl]-12-phthalimido-4-p-toluene-4,9-diazadodecylamindihydrobenzo[b]furan moiety to the selectively protected spermine unit. The synthesis of the ephedradine alkaloid skeleton via an `imine cyclisation
University of Southampton
1986
Cooke, Nigel Graham
(1986)
Identification of the sex pheromone of Nezara viridula (L.) and synthesic studies towards ephedradines A-D.
University of Southampton, Doctoral Thesis.
Record type:
Thesis
(Doctoral)
Abstract
The isolation of the sex pheromones from two populations of Nezara viridula (L.) is described. The sex pheromone produced by male N. viridula (L.), from France, was shown to comprise a 2:1 mixture of (Z)-2-[(1R*,3S*,4R*)-3,4-epoxy-4-methylcyclohexyl]-6-methyl-2,5-heptadiene and (Z)-2-[1R*,3R*,4S*)-3,4-epoxy-4-methylcyclohexyl]-6-methyl-2,5-heptadiene. The male sex pheronone from the Brazilian population was shown to be the single sesquiterpene, (Z)-(-)-2-[(1S,3R,4S)-3,4-epoxy-4-methylcyclohexyl]-6-methyl-2,5-heptadiene. The synthesis of all eight (E/Z)-2-(3,4-epoxy-4-methylcyclohexyl)-6-methyl-2,5-heptadiene isomers is described. Approaches towards 2-aryl-5-formyl-3-methoxy-carbonyl-2,3-dihydro-benzo[b]furans via hexahydro-benzo[b]furan intermediates have been investigated. A general procedure for the preparation of t -2-aryl-5-formyl-3-methoxy-carbonyl-2,3-dihydro-benzo[b]furans by the cyclisation of methyl 2-[2-benzyloxy-5-(dimethoxy-methyl)-phenyl]-3-aryl-3-hydroxypropionate derivatives has been developed. Model studies towards the enantioselective synthesis of the dihyrod-benzo[b]furan moieties of ephedradines A-D are described. Thus, (4R)-(+)-3-[(2R,3R)-2-(2-benzyloxyphenyl)-3-(4-benzyloxyphenyl)-3-hydroxy-1-oxopropyl]-4-isopropyl-2-oxazolidinone (165) was cyclised to give (4R)-(-)-3-[(2R,3R)-2-(4-hydroxyphenyl)-2,3-dihydro-benzo[b]furan-3-ylcarbonyl]-4-isopropyl-R)-(-)-3-[(2R,3R)-2-(4-hydroxyphenyl)-2,3-dihydro-benzo[b]furan-3-ylcarbonyl]-4-isopropyl-2-oxaxolidi Conditions for the condensation ofdro-benzo[b]furan-3-ylcarbonyl]-4-isopropyl-2-oxaxolidinone (166). Conditions for the condensation of boron enolates of thioesters with imines were developed. N-(tert-Butoxycarbonyl)-9-[2R*,3R*)-2-(3,4-dimethoxyphenyl)-5-formyl-2,3-dihydrobenzo[b]furan-3-yl-carbonyl]-12-phthalimido-4-p-toluene-4,9-diazadodecylamindihydrobenzo[b]furan moiety to the selectively protected spermine unit. The synthesis of the ephedradine alkaloid skeleton via an `imine cyclisation
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Published date: 1986
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Local EPrints ID: 460823
URI: http://eprints.soton.ac.uk/id/eprint/460823
PURE UUID: bba5f897-5a48-4105-b10b-0c153505c7d6
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Date deposited: 04 Jul 2022 18:30
Last modified: 04 Jul 2022 18:30
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Author:
Nigel Graham Cooke
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