- Preparation of stereochemically pure E- and Z-alkenoic acids and their methyl esters from bicyclo[n.1.0]alkan-1-ols. Application in the synthesis of insect pheromones
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Oxidative cleavage of exo- and endo-alkyl- and hydroxyalkyl-substituted bicyclo[n.1.0]alkan-1-ols with (diacetoxy-λ3-iodanyl)benzene gave the corresponding methyl alkenoates exclusively with E or Z configuration of the double bond. This reaction was used as the key stage in the syntheses of stereoisomerically pure components of pest insect pheromones: (E)-dodec-9-en-1-yl acetate (European pine shoot moth Rhyacionia buoliana), (Z)-tetradec-11-en-1-yl acetate (European oak leafroller Tortrix viridana), and (3E,8Z,11Z)-tetradeca-3,8,11-trien-1-yl acetate (tomato leafminer Tuta absoluta).
- Zubrytski,Kananovich,Matiushenkov
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p. 813 - 823
(2017/08/02)
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- SELECTIVE HYDROGENATION OF ALDEHYDE WITH RU/BIDENTATE LIGANDS COMPLEXES
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The present invention relates to processes for the reduction by hydrogenation, using molecular H2, of a C5-C20 substrate containing one or two aldehydes functional groups into the corresponding alcohol or diol, characterized in that said process is carried out in the presence of —at least one catalyst or pre-catalyst in the form of a ruthenium complex having a coordination sphere of the N2P2O2, wherein the coordinating atoms N2 are provided by a first bidentate ligand, the coordinating atoms P2 are provided by a second bidentate ligand and the coordinating atoms O2 are provided by two non-linear carboxylate ligands; and —optionally of an acidic additive.
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Paragraph 0205
(2014/09/03)
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- Studies on difficult intramolecular hydroaminations in the context of four syntheses of alkaloid natural products
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Examples of intramolecular alkene hydroaminations forming six-membered ring systems are rare, especially for systems in which the double bond is disubstituted. Such cyclizations have important synthetic relevance. Herein we report a systematic study of these cyclizations using recently developed Cope-type hydroamination methodologies. Difficult intramolecular alkene hydroaminations were used as key steps in syntheses of 2-epi-pumiliotoxin C, coniine, N-norreticuline and desbromoarborescidine A. This effort required the development of optimized hydroamination conditions to improve the efficiency of the cyclizations. Collectively, our results show that Cope-type cyclizations can be achieved on a variety of challenging substrates and proceed under similar conditions for both N-H and N-substituted hydroxylamines.
- Dion, Isabelle,Vincent-Rocan, Jean-Francois,Zhang, Lei,Cebrowski, Pamela H.,Lebrun, Marie-Eve,Pfeiffer, Jennifer Y.,Bedard, Anne-Catherine,Beauchemin, Andre M.
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p. 12735 - 12749
(2014/01/17)
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- Unexpected role of anionic ligands in the ruthenium-catalyzed base-free selective hydrogenation of aldehydes
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Bigger and better: The replacement of anionic chloride ligands in Noyori-type [(diamine)(diphosphine)RuCl2] catalysts with bulky carboxylate ligands enabled the efficient selective hydrogenation of a variety of aldehydes under base-free conditions (see scheme). Turnover numbers of up to 100 000 were reached in the presence of a bulky carboxylic acid co-catalyst. This type of catalytic system probably operates through an inner-sphere mechanism. Copyright
- Dupau, Philippe,Bonomo, Lucia,Kermorvan, Laurent
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supporting information
p. 11347 - 11350
(2013/11/06)
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- COMPOUNDS WITH HERBAL ODOR. V. UNBRANCHED PRIMARY (Z)-ALKENOLS
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The similarity between the odor of alkenols (Z)-CH3-(CH2)n(H=CH(CH2)mOH and the odor of leaf alcohol (m=2, n=1), taken as standard, gradually weakened with change in the m and/or n values and is determined by the number of carbon atoms in the molecules.
- Vasil'ev, A. A.,Cherkaev, G. V.,Nikitina, M. A.
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p. 735 - 739
(2007/10/02)
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- Volatile Flavor Components of Kogyoku Apples
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A steam distillate of Kogyoku apple juice was extracted with ethyl ether.The extract was separated into its acidic and neutral fractions, and the neutral fraction was further separated into five fractions by column chromatography.All these fractions were analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry.Several compounds in the neutral fraction of the juice were isolated by preparative GC, and then identified by comparing their mass, infrared and nuclear magnetic resonance spectra with those of authentic compounds.Sixty-seven compounds were identified form the juice, 22 compounds being found for the first time as apple flavor components.Among them, the following compounds have not been previously reported as flavor components in any natural product; (Z)-5-octen-1-ol, (Z,Z)- and (E,Z)-3,5-octadien-1-ols, (Z,Z)- and (E,Z)-3,5-octadien-1-yl acetates, (Z)-5-octene-1,3-diol and 3-hydroxy-(Z)-5-octen-1-yl acetate.We also made a comparison of the volatile flavor compounds in the juice and peel of the same apples.
- Yajima, Izumi,Yanai, Tetsuya,Nakamura, Mikio,Sakakibara, Hidemasa,Hayashi, Kazuo
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p. 849 - 856
(2007/10/02)
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