- Total synthesis of N,O,O,O-tetraacetyl-d-ribo-phytosphingosine and its 2-epi-congener
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Total synthesis of the natural d-ribo-phytosphingosine I and its 2-epimer III in the protected form was achieved through a common strategy. The aza-Claisen rearrangement of allylic thiocyanate (Z)-V incorporated the new stereogenic centre with nitrogen and the subsequent Wittig olefination constructed a non-polar side chain. Hydrogenation, followed by removal of protecting groups, completed the syntheses of I and III.
- Martinkova, Miroslava,Pomikalova, Kvetoslava,Gonda, Jozef
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Read Online
- The Unexpected Importance of the Primary Structure of the Hydrophobic Part of One-Component Ionizable Amphiphilic Janus Dendrimers in Targeted mRNA Delivery Activity
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Viral and synthetic vectors for delivery of nucleic acids impacted genetic nanomedicine by aiding the rapid development of the extraordinarily efficient Covid-19 vaccines. Access to targeted delivery of nucleic acids is expected to expand the field of nan
- Zhang, Dapeng,Atochina-Vasserman, Elena N.,Lu, Juncheng,Maurya, Devendra S.,Xiao, Qi,Liu, Matthew,Adamson, Jasper,Ona, Nathan,Reagan, Erin K.,Ni, Houping,Weissman, Drew,Percec, Virgil
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p. 4746 - 4753
(2022/03/27)
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- Selective Production of Linear Aldehydes and Alcohols from Alkenes using Formic Acid as Syngas Surrogate
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Performing carbonylation without the use of carbon monoxide for high-value-added products is an attractive yet challenging topic in sustainable chemistry. Herein, effective methods for producing linear aldehydes or alcohols selectively with formic acid as both carbon monoxide and hydrogen source have been described. Linear-selective hydroformylation of alkenes proceeds smoothly with up to 88 % yield and >30 regioselectivity in the presence of single Rh catalyst. Strikingly, introducing Ru into the system, the dual Rh/Ru catalysts accomplish efficient and regioselective hydroxymethylation in one pot. The present processes utilizing formic acid as syngas surrogate operate simply under mild condition, which opens a sustainable way for production of linear aldehydes and alcohols without the need for gas cylinders and autoclaves. As formic acid can be readily produced via CO2 hydrogenation, the protocols represent indirect approaches for chemical valorization of CO2.
- Chen, Junjun,Hua, Kaimin,Liu, Xiaofang,Deng, Yuchao,Wei, Baiyin,Wang, Hui,Sun, Yuhan
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p. 9919 - 9924
(2021/05/31)
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- New strategy for production of primary alcohols from aliphatic olefins by tandem cross-metathesis/hydrogenation
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Primary alcohols are widely used in industry as solvents and precursors of detergents. The classic methods for hydration of terminal alkenes always produce the Markovnikov products. Herein, we reported a reliable approach to produce primary alcohols from terminal alkenes combining with biomass-derived allyl alcohol by tandem cross-metathesis/hydrogenation. A series of primary alcohol with different chain lengths was successfully produced in high yields (ca. 90percent). Computational studies revealed that self-metathesis and hydrogenation of substrates are accessible but much slower than cross-metathesis. This new methodology represents a unique alternative to primary alcohols from terminal alkenes.
- Jia, Ruilong,Zuo, Zhijun,Li, Xu,Liu, Lei,Dong, Jinxiang
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p. 1525 - 1529
(2019/11/11)
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- From alkenes to alcohols by cobalt-catalyzed hydroformylation-reduction
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The cobalt-catalyzed hydroformylation of alkenes in the presence of a range of novel cyclic phosphine ligands was investigated. The effect of various parameters such as solvents, additives, cobalt/phosphine ratio, CO/H2 (1:2), and nature of the alkenes was examined. The results revealed that both terminal and internal alkenes are hydroformylated in high yields to give mainly linear products at moderate temperature and syn gas pressure. The linearity ranges from 43 to 85%, with Lim-10 giving the highest proportion of linear product.
- Achonduh, George,Yang, Qian,Alper, Howard
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supporting information
p. 1241 - 1246
(2015/03/05)
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- One-Carbon Homologation of Primary Alcohols and the Reductive Homologation of Aldehydes Involving a Jocic-Type Reaction
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(Trichloromethyl)carbinols, which are formed in one operation from either alcohols or aldehydes, can be converted into primary alcohols in a Jocic-type reaction involving LiBH4. The net result is a convenient two-step, one-carbon homologation of primary alcohols or a reductive one-carbon homologation of aldehydes featuring a broad substrate scope. The method is step-economical, and it nicely complements established one-carbon homologation strategies. (Trichloromethyl)carbinols, which are formed in one operation from either alcohols or aldehydes, can be converted into primary alcohols in a Jocic-type reaction involving LiBH4. The net result is a convenient two-step, one-carbon homologation of primary alcohols or a reductive one-carbon homologation of aldehydes featuring a broad substrate scope.
- Li, Zhexi,Gupta, Manoj K.,Snowden, Timothy S.
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p. 7009 - 7019
(2015/11/16)
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- AMINE-CONTAINING LIPIDOIDS AND USES THEREOF
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Provided herein are lipidoids that may be prepared from the conjugate addition of alkylamines to acrylates. In some embodiments, provided lipidoids are biodegradable and may be used in a variety of drug delivery systems. Given the amino moiety of the lipidoids, they are well-suited for the delivery of polynucleotides, in addition to other agents. Nanoparticles containing the inventive lipidoids and polynucleotides have been prepared and have been shown to be effective in delivering siRNA.
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Paragraph 00213
(2014/03/22)
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- METHODS FOR THE SYNTHESIS OF PLASMALOGENS AND PLASMALOGEN DERIVATIVES, AND THERAPEUTIC USES THEREOF
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A method for preparing plasmalogens and derivatives thereof represented by Formula B, wherein R1 and R2 are similar or different, derived from fatty acids; R3 is selected from hydrogen and small alkyl groups. The synthetic route involves production of novel cyclic plasmalogen precursors of Formula A and their conversion to plasmalogens and plasmalogen derivatives of Formula B. Also disclosed is the therapeutic use of plasmalogens and derivatives thereof as produced by the synthetic route of the present invention.
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Page/Page column 23-24
(2013/06/05)
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- Tandem isomerization/hydroformylation/hydrogenation of internal alkenes to n-alcohols using Rh/Ru dual-or ternary-catalyst systems
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A one-pot three-step reaction, isomerization/hydroformylation/hydrogenation of internal alkenes to n-alcohols, was accomplished by employing a Rh/Ru dual-catalyst system. By using a combination of Rh(acac)(CO)2/ bisphosphite and Shvo's catalyst, (Z)-2-tridecene was converted to 1-tetradecanol in 83% yield with high normal/iso selectivity (n/i = 12). The method was applicable to other internal alkenes, including functionalized alkenes, such as an alkenol and an alkenoate. Furthermore, addition of a third component, Ru3(CO)12, effectively improved the n/i ratio in the tandem isomerization/hydroformylation/hydrogenation of methyl oleate (from n/i = 1.9 to 4.4). Control experiments revealed that the isomerization was mediated by both Rh and Ru and that the coexistence of Rh and Ru was essential for hydrogenation of aldehyde under H2/CO.
- Yuki, Yamato,Takahashi, Kohei,Tanaka, Yoshiyuki,Nozaki, Kyoko
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p. 17393 - 17400
(2014/01/06)
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- From olefins to alcohols: Efficient and regioselective ruthenium-catalyzed domino hydroformylation/reduction sequence
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Exploring the alternatives: Ruthenium imidazoyl phosphine complexes catalyze the domino hydroformylation/reduction of alkenes to alcohols in good yields and with good selectivities (see scheme). Linear aliphatic alcohols are synthesized under reaction conditions typically used in industrial hydroformylations. Copyright
- Fleischer, Ivana,Dyballa, Katrin Marie,Jennerjahn, Reiko,Jackstell, Ralf,Franke, Robert,Spannenberg, Anke,Beller, Matthias
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supporting information
p. 2949 - 2953
(2013/04/10)
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- Formic acid: A promising bio-renewable feedstock for fine chemicals
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In light of the growing scarcity of petroleum-based raw materials, carbon dioxide (CO2) is becoming increasing attractive as organic carbon source. In this perspective, formic acid (HCOOH) might be an interesting bio-renewable solution to store, transport, and activate carbon dioxide for the synthesis of value-added chemicals. Herein, HCOOH has been successfully used as C1 building block for the synthesis of a library of alcohols via a catalysed oxo-synthesis, under green experimental conditions. Copyright
- Mura, Manuel G.,Luca, Lidia De,Giacomelli, Giampaolo,Porcheddu, Andrea
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supporting information
p. 3180 - 3186
(2013/01/15)
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- Reduction of aromatic and aliphatic esters using the reducing systems MoO2(acac)2 or V(O)(OiPr)3 in combination with 1,1,3,3-tetramethyldisiloxane
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An efficient reduction of aromatic and aliphatic esters with 1,1,3,3-tetramethyldisiloxane in combination with [MoO2(acac) 2] or [V(O)(OiPr)3] is reported. In the former system, the presence of triphenylphosphane oxide allows high conversion and good isolated yield to be reached. For the latter system, no ligand is necessary to obtain the corresponding alcohols with similar results. 1,1,3,3-Tetramethyldisiloxane in association with [MoO2(acac)2] or [V(O)(OiPr)3] was found to efficiently reduce aliphatic and aromatic esters. Copyright
- Pehlivan, Leyla,Metay, Estelle,Laval, Stephane,Dayoub, Wissam,Delbrayelle, Dominique,Mignani, Gerard,Lemaire, Marc
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experimental part
p. 7400 - 7406
(2012/01/06)
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- Ditopic cyclodextrin-based receptors: New perspectives in aqueous organometallic catalysis
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The mass transfer properties of mono- and ditopic β-cyclodextrin-based receptors have been evaluated in a biphasic palladium-catalyzed Tsuji-Trost reaction and compared to one of the best mass-transfer promoters, namely the randomly methylated β-cyclodextrin. While monotopic receptors appeared to be poor mass-transfer promoters of long alkyl chain allyl carbonates or urethanes, cooperative effects have been evidenced with ditopic cyclodextrin-based receptors, opening new perspectives in aqueous organometallic catalysis.
- Six, Natacha,Menuel, Stephane,Bricout, Herve,Hapiot, Frederic,Monflier, Eric
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experimental part
p. 1467 - 1475
(2010/08/19)
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- PRODUCTION OF DETERGENT RANGE ALCOHOLS
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This invention relates to a process for the production of a mixture of detergent-range alcohols having an average of between 8 and 20 carbon atoms per molecule. The process includes the steps of providing a hydrocarbon stream containing olefins and paraffins in which more than 5% by volume of olefin molecules in the hydrocarbon stream have a total number of carbon atoms which is different from the total number of carbon atoms of the most abundant two carbon numbers of olefins in the hydrocarbon stream; reacting the hydrocarbon stream with CO and an alcohol in the presence of a catalyst in a hydroesterification reaction to form a hydrocarbon stream containing esters and paraffins; separating esters from the hydrocarbon stream containing esters and paraffins; and subjecting the esters to a hydrogenation reaction to provide the mixed alcohol product.
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Page/Page column 3
(2009/01/24)
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- Oligomerization catalyst
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An oligomerization catalyst for olefins is obtainable from a) a chromium compound CrX3 and the at least equimolar amount, based on the chromium compound CrX3, of a ligand L or from an existing chromium complex CrX3L, in which the groups X are, independently of one another, abstractable counterions and L is a 1,3,5-triazacyclohexane of the formula I ?where the groups R1 to R9 are, independently of one another: hydrogen or organosilicon or substituted or unsubstituted carboorganic groups having from 1 to 30 carbon atoms, where two geminal or vicinal radicals R1 to R9 may also be joined to form a five—or six-membered ring, andb) at least one activating additive and also a process for preparing oligomers of olefins using these catalysts, the oligomers thus obtainable, and the oxo alcohols obtainable from these oligomers.
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- Chemically modified β-cyclodextrins: Efficient supramolecular carriers for the biphasic hydrogenation of water-insoluble aldehydes
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Hydrogenation of water-insoluble aldehydes can be achieved in high yields in a genuine two-phase system by using a recoverable catalytic system composed of a water-soluble ruthenium/triphenylphosphine trisulfonate complex and a suitable chemically modified β-cyclodextrin.
- Monflier, Eric,Tilloy, Sebastien,Castanet, Yves,Mortreux, Andre
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p. 2959 - 2960
(2007/10/03)
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- Hydroxymethylation of organic halides. Evaluation of a catalytic system involving a fluorous tin hydride reagent for radical carbonylation
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Hydroxymethylation of organic halides 2 using a catalytic amount of fluorous tin hydride 1, CO, and NaBH3CN as a reducing agent, proceeded smoothly to give one-carbon homologated alcohols 5 in good yields. Three phase workup (water-dichloromethane-perfluorohexane) was conveniently performed for the separation of 1 and 5.
- Ryu, Ilhyong,Niguma, Tatsuro,Minakata, Satoshi,Komatsu, Mitsuo,Hadida, Sabine,Curran, Dennis P.
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p. 7883 - 7886
(2007/10/03)
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- Separation of methylene chloride from tetrahydrofuran by extractive distillation
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Methylene chloride is difficult to separate from tetrahydrofuran by conventional distillation or rectification because of the proximity of their vapor pressures. Methylene chloride can be readily separated from tetrahydrofuran by extractive distillation. Effective agents are 1-pentanol, 1,2-butanediol and 3-nitrotoluene.
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- Hydrogenation of carboxylic acids using bimetallic catalysts consisting of Group 8 to 10, and Group 6 or 7 metals
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Hydrogenation of carboxylic acids to alcohols was effectively catalyzed by bimetallic systems consisting of Group 8 to 10 late transition-metals, and Group 6 or 7 early transition-metal carbonyls. These catalysts easily converted α,ω-dicarboxylic acid monoesters into ω-hydroxyalkanoic esters in good yields.
- He, De-Hua,Wakasa, Noriko,Fuchikami, Takamasa
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p. 1059 - 1062
(2007/10/02)
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- Process for production of biodegradable esters
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This invention relates to processes for making biodegradable surfactant. The process comprises several steps including an optional step. The first step is directed to reacting olefins with ZSM-23 catalyst to form oligomers having the formula -(C3)x, (C4)x or mixtures thereof. Second, the oligomer is hydroformylated to form a saturated alcohol, for example, tridecanol. Next, the saturated alcohol is ethoxylated. Thereafter a nonionic biodegradable surfactant is recovered. This surfactant can be used in detergent formulations. A process is also taught for making esters which can be used as lubricants or plasticizers. A specific hydroformylation process is taught which utilizes modified cobalt carbonyl catalyst. Also, a specific ethoxylation process is taught. Products formed according to the latter two processes as well as their uses are also taught.
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- Catalyst and the amination of alcohols under hydrogenating conditions
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Catalysts whose active material contains, in addition to from 20 to 85% by weight, calculated as ZrO2, of oxygen-containing zirconium compounds, from 1 to 30% by weight, calculated as CuO, of oxygen-containing compounds of copper and from 1 to 40% by weight each, calculated as CoO or NiO, respectively, of oxygen-containing compounds of cobalt and of nickel are used for the amination of alcohols under hydrogenating conditions.
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- Hair growth composition containing citric acid esters
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Triesters of citric acid are used for inducing, maintaining or increasing hair growth. Compositions for topical application to mammalian hair or scalp comprise an effective amount of from 1% to 99% by weight of an ester of citric acid having the structure (1): where, R1, R2 and R3 each independently represent a branched or unbranched alkyl, alkenyl, aryl, alkylaryl or arylalkyl group, each said group having from 1 to 18 carbon atoms, R4 represents -H, or a branched or unbranched saturated or unsaturated acyl, alkyl, aryl, alkylaryl or aylalkyl group having from 1 to 18 carbon atoms, in the presence of a cosmetically acceptable vehicle for the citric acid ester and in the absence of solid absorbent for the ester;, said effective amount of said ester being sufficient to increase hair growth in the rat, when said composition is applied topically thereto over a period of no more than three months, by at least 10% more than that obtainable using a control composition from which the said ester has been omitted, in accordance with the Rat Hair Growth Test.
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- Lactones. 2. Enthalpies of hydrolysis, reduction, and formation of the C4-C13 monocyclic lactones. Strain energies and conformations
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The enthalpies of hydrolysis of the monocyclic lactones from γ-butyrolactone to tridecanolactone were determined calorimetrically, and the acyclic ethyl having the number of atoms were studied in the fashion. The enthalpies of reduction of the lactones to the corresponding α,ω-alkanediols with lithium triethylborohydride also were determined. The enthalpies of formation of the lactones and the ethyl esters were derived from these data. They were converted to values for the gas phase by measuring the enthalpies of vaporization of ethyl esters and of lactones. In the of γ-butyrolactone and δ-valerolactone, the enthalpies of formation were in good accord with the previously reported values determined via combustion calorimetry. The strain energies of the lactones were obtained via isodesmic reactions. Valerolactone had a strain energy of 11 kcal/mol, and the largest strain energy was found with octanolactone (13 kcal/mol). The conformations of γ-butyrolactone and δ-valerolactone were studied via MP2/6-31G* geometry optimizations, and the conformations of the other lactones were studied with use of the molecular mechanics program MM3. The energies of the lactones estimated via molecular mechanics were compared with the experimental results.
- Wiberg, Kenneth B.,Waldron, Roy F.
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p. 7697 - 7705
(2007/10/02)
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- SYNTHESIS OF 20-IODOEICOSANOIK AND 20--IODOEICOSANOIK ACIDS
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20-Iodoeicosanoic acid (X) was prepared in 9 steps, its carbon cain being constructed from thiophene and ethyl ester chlorides of dodecanedioic and butanedioic acids.Isotope exchange afforded 20--iodoeicosanoic acid required for scintigraphic studies of the myocardium.Desulfuration of the thiophene precursor VIII was accompanied by formation of side products XI-XIX arising by cleavage of the thiophene C-C bonds.Desulfuration of the model compounds XX and XXI has shown that the formation of these products is general.
- Protiva, Jiri,Pecka, Jaroslav,Urban, Jiri,Zima, Jiri
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p. 1546 - 1554
(2007/10/02)
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- TWO POLYACETYLENIC PHYTOALEXINS FROM ARCTIUM LAPPA
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Key Word Index-Arctium lappa; Compositae; burdock; stress metabolites; phytoalexins; polyacetylenes. Treatment of sliced burdock root tissue with copper (II) sulphate stimulated phytoalexin formation.Two were isolated and characterized as (S)-12,13-epoxy-2,4,6,8,10-tridecapentayne and 1-tridecen-3,5,7,9,11-pentayne by spectroscopic methods and some chemical transformations.
- Takasugi, Mitsuo,Kawashima, Shinji,Katsui, Nobukatsu,Shirata, Akira
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p. 2957 - 2958
(2007/10/02)
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- PHOTOCHEMICAL TRANSFORMATION OF A DITHIOACETAL S-OXIDE INTO THE CORRESPONDING ALDEHYDE
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Irradiation of an aldehyde dithioacetal S-oxide gives the corresponding aldehyde.The mechanism of this photochemical transformation is discussed and its application to organic synthesis is also described.
- Ogura, Katsuyuki,Itoh, Shigeyuki,Takahashi, Kazumasa,Iida, Hirotada
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p. 6381 - 6384
(2007/10/02)
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- Melting Behaviour of Fatty Alcohols and Their Binary Blends
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The m.p. of pure fatty alcohols from undecyl to nonadecyl are determined along with those of their corresponding pure fatty acids and their methyl esters ; alternation in m.ps. does not occur in fatty alcohol series unlike the other two.Eutectic formation does not take place in the binary blends of fatty alcohols, but a maximum depression of the m.p. of the lower homologue occurs in presence of 11.0 +/- 1.0 mole percent of higher one in the blend.
- Gaikwad, B. R.,Subrahmanyam, V. V. R.
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p. 513 - 515
(2007/10/02)
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- Process for preparing olefins by metathesis of cyclic olefins with acyclic olefins
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A process for preparing esters and halides is disclosed comprising the step of reacting a cyclic olefin having the formula I STR1 wherein R1 and R4 are the same or different from each other and each represents hydrogen, methyl, or ethyl; R2 and R3 are the same or different from each other and each represents hydrogen or alkyl containing 1 to 5 carbon atoms; and n represents a whole number from 2 to 12, with an acyclic olefin having the formula II STR2 wherein R5 represents hydrogen, methyl, ethyl or the group STR3 wherein R12 and R13 are the same or different from each other and each represents hydrogen or alkyl containing 1 to 5 carbon atoms; Y represents halogen; an acyloxy group R14 --CO--O wherein R14 represents alkyl containing 1-12 carbon atoms, phenyl or phenyl alkyl containing 7-12 carbon atoms, or an oxycarbonyl group R15 --O--CO wherein R15 represents alkyl containing 1-12 carbon atoms, phenyl or phenyl alkyl containing 7-12 carbon atoms; p represents a whole number from 1-12 except when Y is an R14 CO--O group wherein p is from 2 to 12. R6 and R7 are the same or different from each other and each represents hydrogen, methyl, or ethyl; R8 and R9 are the same or different from each other and each represents hydrogen or alkyl containing 1 to 5 carbon atoms; X represents halogen; an acyloxy group R10 --CO--O--, wherein R10 represents alkyl containing 1-12 carbon atoms, phenyl, or phenylalkyl containing 7-12 carbon atoms, or an oxycarbonyl group R11 --O--CO, wherein R11 represents alkyl containing 1-12 carbon atoms, phenyl, or phenylalkyl containing 7-12 carbon atoms, m represents a whole number from 1-12 except when X is an R10 --CO--O-- group wherein m is from 2 to 12 in the presence of a catalytic composition comprising a halogen-tungsten salt and a reducing agent which is an organic tin compound.
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