- Behaviour of monocomplexed 1,4-diynes in the Khand reaction and use of ethylene equivalent techniques in a convenient route to tritium-labelled methyl jasmonate
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1,2-Complexed hexacarbonyl(hepta-1,4-diyne)dicobalt, obtained from hexacarbonyl(propargyl acetate)dicobalt with tri-1-butynylaluminium, has been converted, by selective Khand annulation of the complexed triple bond with vinyl benzoate, to 2-pent-2-yn-1-ylcyclopent-2-en-1-one. By use of standard procedures this alkynyl cyclopentenone has been transformed into methyl jasmonate, allowing replacement of the final hydrogenation step by tritiation to produce the labelled analogue. Two alternative approaches to the intermediate pentynylcyclopentenone were examined and shown to be unsuccessful.
- Kerr, William J.,McLaughlin, Mark,Pauson, Peter L.
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p. 118 - 124
(2007/10/03)
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- Preparation of (±)-2-(2,3-2H2) jasmonic acid and its methyl ester, methyl (±)-2-(2,3-2H2)jasmonate
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For use as the internal standards in a quantitative analysis of natural jasmonic acid (JA) and methyl jasmonate (JAMe) by gas chromatography-mass spectrometry-selected ion monitoring, (±)-2-(2,3-2H2)JA and its methyl ester, (±)-2-(2,3-2H2)JAMe, were efficiently prepared from 2-(2-pentyl)- 2-cyclopentenone through catalytic semi-deuteriogenation of acetylenic intermediates with deuterium gas in pyridine.
- Seto,Fujioka,Fujisawa,Goto,Nojiri,Yamane,Yoshida
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p. 1709 - 1711
(2007/10/03)
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- CONJUGATE ADDITION OF LITHIOTRIMETHYLSILYLACETATE. A SIMPLE SYNTHESIS OF METHYL JASMONATE VIA VICINAL DOUBLE ALKYLATION
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Exceptional conjugate addition of methyl lithiotrimethylsilylacetate to cyclopentenone has been found and can be applied to a convenient synthesis of methyl jasmonate by sequential vicinal double alkylation via succesful stannyl enolate trapping.
- Nishiyama, Hisao,Sakuta, Koji,Itoh, Kenji
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p. 2487 - 2488
(2007/10/02)
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- Keten Silyl Acetal Chemistry; Simple Synthesis of Methyl Jasmonate and Related Compounds by Utilising Keten Methyl Dimethyl-t-butylsilyl Acetal
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Conjugate addition of keten silyl acetals to α,β-unsaturated carbonyl compounds in acetonitrile gave a quantitative yield of the corresponding methyl (3-trialkylsiloxyalk-2-enyl)acetates; subsequent site-specific electrophilic substitution yielded the corresponding 2-substituted 3-(alkoxycarbonylmethyl)alkanones.These novel addition and sequential alkylation reactions could be applied to a simple synthesis of methyl jasmonate, methyl didehydrojasmonate, and methyl dihydrojasmonate.
- Kita, Yasuyuki,Segawa, Jun,Haruta, Jun-ichi,Yasuda, Hitoshi,Tamura, Yasumitsu
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p. 1099 - 1104
(2007/10/02)
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- An Efficient Synthesis of Methyl Jasmonate and Methyl Dihydrojasmonate
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A simple and an efficient synthesis of methyl jasmonate (1) and methyl dihydrojasmonate (5) is described.Starting from alkyl acetoacetate or acetonedicarboxylate, 1 and 5 were obtained in only a few steps via intramolecular Michael addition.
- Kitahara, Takeshi,Mori, Kenji,Matsui, Masanao,Iwamoto, Minoru,Takagi, Yoshikazu,Warita, Yasuhiro
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p. 1369 - 1376
(2007/10/02)
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- An Efficient Synthesis of Methyl dl-cis-Jasmonate
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An efficient synthesis of methyl dl-cis-jasmonate is described, starting from the previously described 2-(methoxycarbonyl)-3-cyclopentanone (3), itself easily prepared from succinyl chloride and methyl potassium malonate.Alkylation of 3 with 1-bromo-2-pentyne followed by selective removal of the 2-carbomethoxy group gave dehydrojasmonic acid.On esterification and reduction (H2/Pd/C/pyridine) of the triple bond to the cis olefin, dehydrojasmonic acid afforded methyl dl-cis-jasmonate in 40percent overall yield from succinyl chloride.
- Johnson, Francis,Paul, Kenneth G.,Favara, D.
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p. 4254 - 4255
(2007/10/02)
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