- 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 0183-0184
(2021/10/02)
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- Exploring London Dispersion and Solvent Interactions at Alkyl–Alkyl Interfaces Using Azobenzene Switches
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Interactions on the molecular level control structure as well as function. Especially interfaces between innocent alkyl groups are hardly studied although they are of great importance in larger systems. Herein, London dispersion in conjunction with solvent interactions between linear alkyl chains was examined with an azobenzene-based experimental setup. Alkyl chains in all meta positions of the azobenzene core were systematically elongated, and the change in rate for the thermally induced Z→E isomerization in n-decane was determined. The stability of the Z-isomer increased with longer chains and reached a maximum for n-butyl groups. Further elongation led to faster isomerization. The origin of the intramolecular interactions was elaborated by various techniques, including 1H NOESY NMR spectroscopy. The results indicate that there are additional long-range interactions between n-alkyl chains with the opposite phenyl core in the Z-state. These interactions are most likely dominated by attractive London dispersion. This work provides rare insight into the stabilizing contributions of highly flexible groups in an intra- as well as an intermolecular setting.
- Strauss, Marcel A.,Wegner, Hermann A.
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supporting information
p. 18552 - 18556
(2019/11/19)
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- 1-HALOALKADIENE AND A PROCESS FOR PREPARING THE SAME AND A PROCESS FOR PREPARING (9e, 11z)-9,11-HEXADECADIENYL ACETATE
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A process to prepare (9E,11Z)-9,11-hexadecadienyl acetate with a good yield and high purity of the general formula (1): CH3—(CH2)3—CH═CH—CH═CH—(CH2)a—X.=The process includes a step of conducting a Wittig reaction between a haloalkenal of the general formula (2): OHC—CH═CH—(CH2)a—X, and a triarylphosphonium pentylide of the general formula (3): CH3—(CH2)3—CH?—P+Ar3, to obtain the 1-haloalkadiene, and the use of a (7E,9Z)-1-halo-7,9-tetradecadiene obtained by the process for a process of preparing (9E, 11Z)-9,11-hexadecadienyl acetate.
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Paragraph 0178-0179
(2019/11/05)
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- PROCESS FOR PREPARING (9e, 11z)-9,11-HEXADECADIENAL
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An efficient process for preparing (9E,11Z)-9,11-hexadecadienal of formula (4) is provided. The process includes at least steps of: conducting a nucleophilic substitution reaction between an (8E,10Z)-8,10-pentadecadienyl magnesium halide derived from an (8E,10Z)-1-halo-8,10-pentadecadiene of (1): and an orthoformate ester (2) to thereby prepare a (9E, 11Z)-1,1-dialkoxy-9, 11-hexadecadiene (3): and hydrolyzing the (9E, 11Z)-1,1-dialkoxy-9,11-hexadecadiene (3) to obtain (9E, 11Z)-9,11-hexadecadienal (4).
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Paragraph 0074-0076
(2019/11/11)
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- Synthesis of fluorinated analogues of sphingosine-1-phosphate antagonists as potential radiotracers for molecular imaging using positron emission tomography
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Sphingosine-1-phosphate (S1P) receptors play major roles in cardiovascular, immunological and neurological diseases. The recent approval of the sphingolipid drug Fingolimod (Gilenya), a sphingosine-1-phosphate agonist for relapsing multiple sclerosis, in 2010 exemplifies the potential for targeting sphingolipids for the treatment of human disorders. Moreover, non-invasive in vivo imaging of S1P receptors that are not available till now would contribute to the understanding of their role in specific pathologies and is therefore of preclinical interest. Based on fluorinated analogues of the S1P1receptor antagonist W146 showing practically equal in vitro potency as the lead structure, the first S1P receptor antagonist [18F]-radiotracer has been synthesized and tested for in vivo imaging of the S1P1receptor using positron emission tomography (PET). Though the tracer is serum stable, initial in vivo images show fast metabolism and subsequent accumulation of free [18F]fluoride in the bones.
- Prasad, Vysakh Pushpa,Wagner, Stefan,Keul, Petra,Hermann, Sven,Levkau, Bodo,Sch?fers, Michael,Haufe, Günter
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p. 5168 - 5181
(2015/02/19)
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- Solvent free and regioselective hydroboration of terminal double bond for synthesis of Z-11-hexadecenol
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Z-11-Hexadecenol was synthesized in high yield by Wittig and hydroboration reactions without solvent. Initially 1,1 1-hexadecadiene was synthesized as a result of Wittig reaction between n-pentyl bromide and C -11 aldehyde. Later hydroboration of the diene formed was carried out by in situ generation of borane using sodium borohydride and boron trifluride etherate. The significance of the process lies on the fact that it is solvent free as well as regioselective and the borane:diene ratio was taken as 1:6. The trialkyl borane formed as the result of the above reaction was filtered and the excess diene was recovered. Further oxidation of trialkyl borane resulted in the formation of Z-11-hexadecenol of > 95 % purity. The excess diene recovered from hydroboration reaction showed more purity than its precursor and can be reused again. Thus this method was found to give more atom economy and the process can be scaled up easily without affecting the isomeric purity.
- Gopi, Sreeraj,Balasubramani,Narasimhan
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experimental part
p. 3771 - 3772
(2012/02/02)
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- Synthesis and biological activity of new diarylalkenes
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Condensation of 5-nitro-, 3-chloro-, and 5-chlorosalicylic acid with formaldehyde afforded dimeric disalicylmethanes which were O-methylated with dimethyl sulfate and oxidized with chromium(VI) oxide to give the diarylketones 10, 11, 12. Wittig reaction with ylides obtained by deprotonation of alkyltriphenylphosphonium salts with sodium bis (trimethylsilyl)amide yielded a series of diarylalkenes. Some of the obtained compounds showed high antimicrobial activity in vitro against Bacillus subtilis and Mycobacterium smegmatis.
- Golebiewski, W. Marek,Cieniecka-Ros?onkiewicz,Szybinska
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- Synthesis of α-tocopherol analogues
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A range of α-tocopherol analogues of varying side-chain length and structure has been prepared by the Wittig reaction of alkyltriphenylphosphonium bromides with either 6-benzyloxy-2,5,7,8-tetramethylchroman-2-carbaldehyde (8) or 6-acetoxy-2,5,7,8,-tetramethylchroman-2-carbaldehyde (14). These analogues include 2-hexyl-2,5,7,8-tetramethylchroman-6-ol (11), 2-heptyl-2,5,7,8-tetramethylchroman-6-ol (12) and 2,5,7,8-tetramethyl-2-(pent-l-enyl)chroman-6-ol (15). Methoxycarbonylmethyl 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylate (2) was formed by reaction of the triethylammonium salt of trolox (1) with methyl bromoacetate. Reaction of methoxycarbonylmethyltriphenylphosphonium bromide (16) with (8) did not produce the expected methyl 3-(6-benzyloxy-2,5,7,8-tetramethylchroman-2-yl)prop-2-enoate (17), but rather 4-(6-benzyloxy-2,5,7,8-tetramethylchroman-2-yl)but-3-en-2-one (22). A proposed mechanism for this unusual reaction is discussed.
- Suarna, Cacang,Dean, Roger T.,Southwell-Keely, Peter T.
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p. 1129 - 1135
(2007/10/03)
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- Synthesis of (3Z,13Z)-3,13-octadecadienyl acetate - Sex pheromone of Synanthedon tenuis-using readily available C11-synthon
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Synthesis of (3Z,13Z)-3,13-octadecadienyl acetate has been achieved from the readily available 10-undecen-1-ol using cheaper reagents and less number of steps. In the key step alkylation of an alkyne is performed with solid sodamide giving the product in 50% yield. The method can be easily scaled-up.
- Narasimhan,Ganeshwar Prasad,Madhavan
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- Synthesis of Alkylphenols and -catechols from Plectranthus albidus (Labiatae)
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In the preceding paper, we described the isolation and structure elucidation of a series of even-numbered phenol- or pyrocatechol-derived 1-arylalkane-5-ones.To establish the assigned structures unambiguously and to have larger quantities available for physiological testing, the following compounds were prepared: in the alkylphenol series, 1-(4'-hydroxyphenyl)tetradecan-5-one (2a), 1-(4'-hydroxyphenyl)hexadecan-5-one (2b), and 1-(4'-hydroxyphenyl)octadecan-5-one (2c); in the alkylcatechol series, 1-(3',4'-dihydroxyphenyl)decan-5-one (3a; not isolated as a natural compound), 1-(3',4'-dihydroxyphenyl)dodecan-5-one (3b), 1-(3',4'-dihydroxyphenyl)tetradecan-5-one (3c), 1-(3',4'-dihydroxyphenyl)hexadecan-5-one (3d), 1-(3',4'-dihydroxyphenyl)octadecan-5-one (3e), and 1-(3',4'-dihydroxyphenyl)icosan-5-one (3f); in the alkenylphenol series, (Z)-1-(4'-hydroxyphenyl)octadec-13-en-5-one (4a) and (E)-1-(4'-hydroxyphenyl)octadec-13-en-5-one (4b); in the alkenylcatechol series, (E,E)-1-(3',4'-dihydroxyphenyl)deca-1,3-dien-5-one (1) and (Z)-1-(3',4'-dihydroxyphenyl)octadec-13-en-5-one (5).All compounds proved to be identical with the previously assigned structures.Compound 1 was synthesized by regioselective aldol condensation of heptan-2-one with (E)-3-(3',4'-dimethoxyphenyl)prop-2-enal (6d; Scheme 1), the phenols 2a-c and the catechols 3a-f by addition of the corresponding alkyl Grignard reagent to 5-(4'-methoxyphenyl)- or 5-(3',4'-dimethoxyphenyl)pentanal (17c and 18c, resp.; Scheme 4), and the olefins 4a, 4b and 5 from 17c or 18c via the 9-O-silyl-protected 13-(4'-methoxyphenyl)- or 13-(3',4'-dimethoxyphenyl)tridecanals (26 and 27, resp.) and Wittig olefination as the key steps (Scheme 5).
- Buergi, Christoph,Liu, Gui,Rueedi, Peter
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p. 1901 - 1915
(2007/10/02)
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- Pheromones: 87. An efficient synthesis of (6E,11Z)-6,11-hexadecadienyl acetate and (6E,11Z)-6,11-hexadecadienal: Female sex pheromone components of Antheraea pernyi and A. polyphemus (Lepidoptera: Saturniidae)
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(6E,11Z)-Hexadecadienyl acetate (15) and the corresponding aldehyde 16, the female sex pheromone components of Antheraea pernyi and A. polyphemus (Lepidoptera; Saturniidae) have been synthesized in 32% and 27% overall yields, respectively, and in 99% isomeric purity. Tetrahydropyran (1) was used as the starting material to obtain 5-bromopentanol (3) which was subsequently chain elongated to 7-(tetrahydropyran-2-yloxy)-1-heptyne (5) by the standard procedures. The organolithium compound from 5 was coupled with (Z)-1-bromo-4-nonene (11), obtained from the Wittig reaction between pentyltriphenylphosphonium bromide (9) and 4-(tetrahydropyran-2-yloxy)butanal (8) followed by bromination. The product, (Z)-1-(tetrahydropyran-2-yloxy)-11-hexadecen-6-yne (12) which resulted, was reduced with sodium/liquid ammonia to give 13 with the E-6 bond. Removal of the protecting group resulted in the desired alcohol 14 which on acetylation and oxidation gave the desired acetate 15 and the aldehyde 16, respectively.
- Bestmann,Gunawardena
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p. 1239 - 1241
(2007/10/02)
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- Studies related to fatty acid desaturation. Part I: Preparation of methyl-substituted nonanols, nonyl bromides and total synthesis of new branched oleic acids
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Convenient pathways for the synthesis of seven structurally defined isomers of methyl-nonanols and methyl-nonylbromides are described.These synthons are used to perform Wittig reactions between convenient phosphoranes and aldehydes in order to obtain seven new octadecenoic acids bearing a methyl grouping on carbons 11 to 17. branched nonan-1-ols / branched 1-nonylbromides / Wittig reactions / methyl 9-bromononanoate / methyl 8-formyloctanoate / methyl 11 or 17-methyloctadec-9-enoates
- Genard, S.,Patin, H.
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p. 397 - 406
(2007/10/02)
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- SYNTHESIS OF PHEROMONES, IV. CHEMISTRY OF THE WITTIG REACTION, I. EFFECTS OF REACTION CONDITIONS ON THE STEREOSELECTIVITY AND YIELD OF THE WITTIG REACTION
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The reactions of nonstabilized triphenylphosphorus ylides with aldehydes have been studied in detail.The stereochemistry and yields of the alkene products are highly dependent upon base used for the generation of the ylide, the solvent and reaction temperature.The synthesis of sex pheromone components by Wittig reaction are also described.
- Vinczer, Peter,Juvancz, Zoltan,Novak, Lajos,Szantay, Csaba
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p. 797 - 820
(2007/10/02)
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- The Stereocontrolled Horner-Wittig Reaction: Synthesis of Disubstituted Alkenes
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Addition of the lithium derivatives of phosphine oxides Ph2P(O)CH2R1 to aldehydes gives erythro adducts (11) with good stereoselectivity.Reduction of α-diphenylphosphinoyl ketones (12) gives threo adducts (11) with even better stereoselectivity.Purification by flash chromatography and/or crystallisation followed by elimination of Ph2PO2 gives pure Z- or E-alkenes with high material conversion.Explanations are offered for the stereoselectivities, conditions defined for full stereochemical control, and guidelines suggested for approaches to a given alkene.
- Buss, Antony D.,Warren, Stuart
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p. 2307 - 2326
(2007/10/02)
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- SIMPLE AND STEREOCONTROLLED SYNTHESIS OF AN OPTIMAL ISOMERIC MIXTURE OF 3,13-OCTADECADIEN-1-YL ACETATES
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A simple route has been developed for the preparation of the optimal isomeric mixture of 3,13-octadecadien-1-yl acetates (ODDA) which is the active sex pheromone of many Synanthedon species.The stereocontrolled formation of double bonds have been achieved via Wittig reaction and subsequent reduction of C-C triple bond.
- Vinczer, Peter,Baan, Gabor,Juvancz, Zoltan,Novak, Lajos,Szantay, Csaba
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p. 1257 - 1270
(2007/10/02)
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