- PROCESS FOR PREPARING A FORMYLALKENYL ALKOXYMETHYL ETHER COMPOUND AND PROCESSES FOR PREPARING CONJUGATED DIENE COMPOUNDS FROM THE SAME
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The present invention provide for preparing a formylalkenyl alkoxymethyl ether compound of the following general formula (2): R3CH2OCH2O(CH2)aCH═CHCHO (2), wherein R3 represents a hydrogen atom, an n-alkyl group having 1 to 9 carbon atoms, or a phenyl group; and “a” represents an integer of 1 to 10, the process comprising: hydrolyzing a dialkoxyalkenyl alkoxymethyl ether compound of the following general formula (1): R3CH2OCH2O(CH2)aCH═CHCH(OR1)(OR2) (1), wherein R1 and R2 represent, independently of each other, a monovalent hydrocarbon group having 1 to 15 carbon atoms, or R1 and R2 may form together a divalent hydrocarbon group, R1-R2, having 2 to 10 carbon atoms; and R3 and “a” are as defined above, in the presence of an acid while removing an alcohol compound thus generated to form the formylalkenyl alkoxymethyl ether compound (2).
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Paragraph 0195-0199
(2021/10/02)
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- Z-Selective Cross-Metathesis and Homodimerization of 3E-1,3-Dienes: Reaction Optimization, Computational Analysis, and Synthetic Applications
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Olefin metathesis reactions with 3E-1,3-dienes using Z-selective cyclometalated ruthenium benzylidene catalysts are described. In particular, a procedure for employing 3E-1,3-dienes in Z-selective homodimerization and cross-metathesis with terminal alkenes is detailed. The reaction takes advantage of the pronounced chemoselectivity of a recently reported ruthenium-based catalyst containing a cyclometalated NHC ligand for terminal alkenes in the presence of internal E-alkenes. A wide array of commonly encountered functional groups can be tolerated, and only a small excess (1.5 equiv) of the diene coupling partner is required to achieve high yields of the desired internal E,Z-diene cross-metathesis product. Computational studies have been performed to elucidate the reaction mechanism. The computations are consistent with a diene-first pathway. The reaction can be used to quickly assemble structurally complex targets. The power of this cross-metathesis reaction is demonstrated by the concise syntheses of two insect pheromones.
- Luo, Shao-Xiong,Cannon, Jeffrey S.,Taylor, Buck L. H.,Engle, Keary M.,Houk,Grubbs, Robert H.
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p. 14039 - 14046
(2016/11/06)
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- Insect pheromones and their analogs LIX. A new method for the synthesis of components of the sex pheromones of insects of the genus Malacosoma
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A new method has been developed for the synthesis of the main components of the sex pheromones of insects of the Malacasoma genus that is based on the selective transformation of the product of the partial ozonolysis of cyclohexa-1,4-diene - methyl 6-oxohex-4E-enoate.
- Kukovinets,Kasradze,Salimova,Odinokov,Galin,Fedorov
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p. 358 - 360
(2007/10/03)
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- OZONOLYSIS OF ALKENES AND THE REACTIONS OF POLYFUNCTIONAL COMPOUNDS LII. SELECTIVE OZONOLYSIS OF (E)-2,7-OCTADIENAL AND (E)-3,7-DIMETHYL-2,6-OCTADIENAL IN THE SYNTHESIS OF INSECT PHEROMONES
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The partial ozonolysis of (E)-2,7-octadienal and (E)-3,7-dimethyl-2,6-octadienal led to (E)-7,7-dimethoxy-2-heptenal and (E)-1,6-diacetoxy-3-methyl-2-hexene.The products were used for the synthesis of (5E,7Z)-5,7-dodecadienal and the corresponding alcohol and acetate , 4,8-dimethyldecanal , and (E)-4-methyl-1,1-dimethoxy-8-oxo-4-nonene .
- Odinokov, V. N.,Ishmuratov, G. Yu.,Sokol'skaya, O. V.,Galeeva, R. I.,Muslukhov, R. R.,Tolstikov, G. A.
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- SYNTHESIS OF INSECT ATTRACTANTS (SEX ATTRACTANTS). VIII. STEREOSELECTIVE SYNTHESIS OF FOUR ISOMERS OF 5,7-DODECADIEN-1-OL AND THEIR ACETATES AND ALDEHYDES, COMPONENTS OF THE SEX PHEROMONES OF INSECTS OF THE Lasiocampidae (Lepidoptera) FAMILY
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A new method is proposed for the stereoselective synthesis of four stereoisomers of 5,7-dodecadien-1-ol and their acetates and aldehydes on the basis of the Wittig reaction. 7-(2-Tetrahydropyranyloxy)-2-heptyn-1-ol was obtained by the alkylation of 2-propyn-1-ol with 2-(4-bromobutoxy)tetrahydropyran.By hydrogenation in the presence of colloidal nickel catalyst or by reduction with lithium aluminum hydride it was converted into the Z and E isomers respectively of 7-(2-tetrahydropyranyloxy)-2-hepten-1-ol.Oxidation of the alcohol group in the above-mentioned hydroxy acetals led to the corres ponding aldehydes, which then entered into the Wittig reaction with pentylidenetriphenylphosphorane under the conditions for the formation of a double bond with a specific configuration of the isomers (Z and E).Subsequent removal of the tetrahydropyranyl protection of the alkyl group in the Wittig reaction products gave 5,7-dodecadien-1-ols, which were converted into the corresponding acetates of the aldehydes by acetylation of oxidation.The products are components of the sex pheromones of insects of the Lasiocampidae family.
- Kovalev, B. G.,Rastegaeva, V. M.,Kurts, A. L.,Bundel', Yu. G.
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p. 1632 - 1638
(2007/10/02)
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- Mass Spectra of Dodecadienic Compounds with a Conjugated Double Bond, Lepidopterous Sex Pheromones
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All geometrical isomers of 5,7-, 6,8-, 7,9-, 8,10- and 9,11-dodecadien-1-ols, and their acetates and aldehyde derivatives were analyzed by electron impact mass spectrometry.The abundance of molecular ion (M(1+)) was observed in every spectrum, and the relative intensity of M(1+) tended to be strong if the compound possessed an (E)-double bond(s).In addition to M(1+), (1+) (alcohols) and (1+) (acetates), every dienic compound showed typical series of CnH(2n-2)(1+)CnH(2n-5)(1+) with abundance maxima around C4, C5, C6 or C7.Each double bond positional isomer characteristically yielded different ion peaks in the series, which were useful for its distinction from other isomers.These results indicate that the chemical structure of a natural pheromone of Lepidoptera is easily deduced successfully by GC-MS analysis if it is a conjugated dienic pheromone.
- Ando, Tetsu,Katagiri, Yoshio,Uchiyama, Masaaki
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p. 413 - 422
(2007/10/02)
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