- Calcium(II)- And Triflimide-Catalyzed Intramolecular Hydroacyloxylation of Unactivated Alkenes in Hexafluoroisopropanol
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We report an efficient intramolecular hydroacyloxylation of unactivated alkenes, offering a streamlined access to relevant γ-lactones, which features the utilization of either a calcium(II) salt or triflimide as a catalyst in hexafluoroisopropanol. This method could be applied to the synthesis of natural products and the late-stage functionalization of natural and bioactive molecules. Additionally, DFT computations were used to elucidate the twist of reactivity observed between the hydroamidation and hydroacyloxylation of unactivated alkenes regarding the formation of 5- and 6-membered rings.
- Qi, Chenxiao,Yang, Shengwen,Gandon, Vincent,Leb?uf, David
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supporting information
p. 7405 - 7409
(2019/10/02)
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- W(OTf)6-Catalyzed Synthesis of Γ-Lactones by Ring Contraction of Macrolides or Ring Closing of Terminal Hydroxyfatty Acids in Ionic Liquid
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γ-Lactones are an important class of fine chemical products and are widely used in perfumes, medicines, pesticides, dyes, and other fields. Herein, a new method for γ-lactones preparation based on ring contraction was developed. Starting from macrolides, W(OTf)6 was used to catalyze the ring-opening polymerization then depolymerization. The depolymerization step was not a common ring-closing process, and the carbon number of the ring was reduced one by one by rearrangement to form the most thermodynamically stable five-membered ring compounds. γ-Caprolactone (180 °C for 10 h) was obtained in a yield of 94 % when [EMIM]OTf was used as the solvent, and the yield of isolated product was up to 85 %. The interaction of various components and the reaction mechanism were studied by FTIR spectroscopy and 1H NMR spectroscopy, respectively. Furthermore, γ-lactones could be produced when the substrate was extended to terminal hydroxyfatty acids. Unexpectedly, the catalyst was poisoned by 1 equivalent of H2O added during the process and thus the yield decreased greatly. The reaction is green and simple, and proceeds in one pot with high atom economy (100 % for macrolides and with water as the only byproduct for terminal hydroxyfatty acid), which provides a promising approach to synthesizing γ-lactones.
- Xie, Zhong-Yu,Deng, Jin,Fu, Yao
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p. 2332 - 2339
(2018/07/31)
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- Preparation method of gamma-caprolactone
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The invention provides a preparation method of gamma-caprolactone. The preparation method comprises the following steps of using at least one of 6-caprolactone, poly(epsilon-caprolactone) and 6-hydroxycaproic acid as a raw material and a Lewis acid as a catalyst, and carrying out rearrangement reaction under a condition that a reaction temperature is 50 to 250 DEG C, so that the gamma-caprolactone is obtained. According to the preparation method, through using the Lewis acid as the catalyst, the raw material is subjected to one-step conversion, so that the gamma-caprolactone can be obtained; the preparation method has the characteristics of simple process, easy purification, high yield, greenness, safety and the like, and is suitable for large-scale industrialized production.
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Paragraph 0036; 0037; 0038; 0045; 0046; 0047
(2017/08/28)
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- 1H-pyrrole-2,4-dicarbonyl-derivatives and their use as flavoring agents
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The present invention primarily relates to 1H-pyrrole-2,4-dicarbonyl-derivatives of Formula (I) wherein R1, R2, R3, Z. Z' and J are as defined in the description, to mixtures thereof and to the use thereof as flavoring agents. The compounds in accordance with the present invention are suitable for producing, imparting, or intensifying an umami flavor. The invention further relates to flavoring mixtures, compositions for oral consumption as well as ready-to-eat, ready-to-use and semifinished products, comprising an effective amount of the compound of Formula (I) or of a mixture of compounds of Formula (I) and to specific methods for producing, imparting, modifying and/or intensifying specific flavor impressions.
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- Imidazo[1,2-a]pyridine-ylmethyl-derivatives and their use as flavoring agents
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The present invention primarily relates to imidazo[1,2-a]pyridine-ylmethyl-derivatives of Formula (I) wherein R1, R2, X, W e J are as defined in the description, to mixtures thereof and to the use thereof as flavoring agents. The compounds in accordance with the present invention are suitable for producing, imparting, or intensifying an umami flavor. The invention further relates to flavoring mixtures, compositions for oral consumption as well as ready-to-eat, ready-to-use and semifinished products, comprising an effective amount of the compound of Formula (I) and to specific methods for producing, imparting, modifying and/or intensifying specific flavor impressions.
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- γ-valerolactone ring-opening and decarboxylation over SiO 2/Al2O3 in the presence of water
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γ-Valerolactone (GVL) has been identified as a promising, sustainable platform molecule that can be produced from lignocellulosic biomass. The chemical flexibility of GVL has allowed the development of a variety of processes to prepare renewable fuels and chemicals. In the present work involving a combination of computational and experimental studies, we explore the factors governing the ring-opening of GVL to produce pentenoic acid isomers, as well as their subsequent decarboxylation over acid catalysts or hydrogenation over metal catalysts. The ring-opening of GVL has shown to be a reversible reaction, while both the decarboxylation and hydrogenation reactions are irreversible and kinetically controlled under the conditions studied (temperatures from about 500 to 650 K). The most significant contributor to lactone reactivity toward ring-opening is the size of the ring, with γ- lactones being more stable and less readily opened than δ- and ε-analogues. We have observed that the presence of either a C=C double bond or a lactone (which opens to form a C=C double bond) is necessary for appreciable rates of decarboxylation to occur. Olefinic acids exhibit higher rates of decarboxylation than the corresponding lactones, suggesting that the decarboxylation of alkene acids provides a lower energy pathway to olefin production than the direct decarboxylation of lactones. We observe lower rates of decarboxylation as the chain length of alkene acids increases; however, acrylic acid (3-carbon atoms) does not undergo decarboxylation at the conditions tested. These observations suggest that particular double bond configurations yield the highest rates of decarboxylation. Specifically, we suggest that the formation of a secondary carbenium ion in the β position leads to high reactivity for decarboxylation. Such an intermediate can be formed from 2- or 3-alkene acids which have at least four carbon atoms.
- Bond, Jesse Q.,Martin Alonso, David,West, Ryan M.,Dumesic, James A.
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experimental part
p. 16291 - 16298
(2011/12/02)
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- Synthesis of (±)-4-alkanolides from pent-4-enoic acid
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Synthesis of (±)-4-hexanolide, (±)-4-nonanolide, and (±)-4-dodecanolide, racemic forms of the insect signal substances, has been accomplished by cationic cyclization of pent-4-enoic acid and its amide in the key step.
- Ugurchieva,Lozanova,Zlokazov,Veselovsky
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experimental part
p. 657 - 659
(2009/05/16)
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- SELECTIVE OXIDATION OF ORGANIC COMPOUNDS
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This invention relates to the selective oxidation of organic compounds. According to the invention organic compounds are selectively oxidized using a peracid or a source of peracid, a transition metal based heterogeneous catalysts and a borate or boric acid in the presence of water. Using the process of the present invention, both excellent conversion and product selectivity maybe obtained.
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Page/Page column 22
(2008/06/13)
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- Cycloisomerization of olefinic carboxylic acids catalyzed by trifluoromethanesulfonic acid
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The trifluoromethanesulfonic acid-catalyzed cyclization of various differently substituted unsaturated carboxylic acids affords selectively substituted lactones in good yields. The reactions use 0.5 to 5% molar ratio of catalyst and can be run without solvent.
- Coulombel, Lydie,Dunach, Elisabet
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p. 153 - 160
(2007/10/03)
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- Deiodination of iodolactones by transfer hydrogenolysis using Raney nickel and 2-propanol
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Raney nickel in refluxing 2-propanol is an effective catalytic system for reducing iodolactones into their corresponding lactones.
- Mebane, Robert C.,Grimes, Kimberly D.,Jenkins, Summer R.,Deardorff, Jonathan D.,Gross, Benjamin H.
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p. 2049 - 2054
(2007/10/03)
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- Reactions of hydriodic acid with aldonolactones and n-alkanolactones. Interconversions between lactones and iodocarboxylic acids
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Aldonolactones containing from four to eight carbon atoms, and lactones of the related monohydroxy-n-alkanoic acids, were subjected to reaction with 57 percent hydriodic acid at 125 deg C.As in the classical studies of Kiliani, the reduction of D-glycero-D-ido-heptono-1,4-lactone yielded mainly γ-heptanolactone.Analogously, the corresponding γ-alkanolactones were obtained as major products from the 1,4-lactones of the D-xylono, D-allono-, and D-erythro-L-talo-octono configuration.Monoiodo-n-alkanoic acids were also formed in admixture with the lactones in all of these reactions.D-Erythrono-1,4-lactone was unique among the aldonolactones in that it led only to an acid, i.e., 3-iodo-n-butanoic acid.The latter was also the product of the non-reductive reaction of hydriodic acid with β-butyrolactone whereas, by contrast, γ-butyrolactone afforded 4-iodobutanoic acid.Among compounds in the five to eight carbon series, it was found that under conditions close to equilibrium the ratio of lactone to iodoacid decreased progressively with the length of the carbon chain; e.g., in the 4 h reactions of γ-valero, γ-capro, γ-heptano,- and γ-octanolactone, the ratios were 2.4, 1.2, 0.2, and 0.1, respectively.An accompanying characteristic of these reactions is a progression in the number of isomeric iodoacids formed.Whereas γ-valerolactone was accompanied by 4-iodopentanoic acid, there were two isomers (4- and 5-) of iodohexanoic acid, three monoiodo- (including 6-iodo-) heptanoic acids, and four (including 7-iodo-) octanoic acids.In all instances, the isomer substituted at the penultimate carbon was major.An interplay of several individual reactions, including ring-opening displacements, eliminations-additions, and rearrangements, as well as a probable influence of entropy changes on the lactone-acid equilibria, appear to account largely for these observations.
- Liu, Zhengchun,Granata, Alessandro,Shen, Xinhua,Perlin, Arthur S.
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p. 2081 - 2088
(2007/10/02)
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- Rhodium carbonyl-catalyzed carbonylation of unsaturated compounds V. Cross-hydrocarbonylation of 1-alkyne and ethylene by rhodium carbonyl catalyst modified with phosphines
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In the presence of Rh4(CO)12 catalyst modified with triphenylphosphine the cross-hydrocarbonylation of 1-alkyne (RC2H; R = Me, Et, nPr, nBu, and tBu) and ethylene using 2-propanol as the hydrogen donor gives 3-alkyl-5-ethyl-2(5H)-furanone (4, 44-69percent), along with a small amount of 4-alkyl-5-ethyl-2(5H)-furanone (5, 1-8percent). when acetylene itself is used, γ-caprolactone (6a), which is the hydrogenation product of the expected 5-ethyl-2(5H)-furanone (4a), is obtained.The yield of 6a depends on the nature of the phosphine employed and decreases in the following order: PR3 = P(C6H4F-p)3 > PPh3 > P(C6H4Me-p)3 > P(C6H4OMe-p)3 > PPh2Et > PPhEt2 > PEt3.
- Hong, Pangbu,Mise, Takaya,Yamazaki, Hiroshi
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p. 291 - 300
(2007/10/02)
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- A one-pot synthesis of racemic and enantiomeric γ-butyrolactones
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Borinate esters 4, derived from the hydroboration of homoallylic alcohols 2 were oxidized with chromic acid to provide a one-pot synthesis of the racemic and enantiomeric γ-butyrolactones (2-oxotetrahydrofurans) 3.
- Mandal,Mahajan
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p. 311 - 313
(2007/10/02)
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- An expeditious enantioselective synthesis of γ-lactones
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α-Alkoxyorganolithium reagents react with α,β-unsaturated trimethylhydrazides to give γ-alkoxytrimethylhydrazides in moderate to good yields. Acid hydrolysis of the latter compounds yields γ-lactones. A short enantioselective route to (S)-hexanolide is described.
- Chong,Mar
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p. 1981 - 1984
(2007/10/02)
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- N-Benzyl-3-(tri-n-butylstannyl)thiopropionamide as Thiohomoenolatesynthon. Application to a Synthesis of Some Heterocycles
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N-Benzyl-3-(tri-n-butylstannyl)thiopropionamide undergoes metalexchange with n-butyllithium.The resulting thiohomoenolate dianion reacts with elestrophiles (aldehydes and ketones) to give the γ-hydroxythioamides, which are transformed into lactones, iminothiolactones, and thiolactams with simple elaboration.
- Takahata, Hiroki,Ohkura, Etsuko,Ikuro, Kazumi,Yamazaki, Takao
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p. 285 - 292
(2007/10/02)
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- The Key Role of Water in the Heterogeneous Permanganate Oxidation of ω-Hydroxy Alkenes
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Potassium permanganate-copper sulphate in dichloromethane in the presence of a catalytic amount of water effects a smooth oxidative cyclization of ω-hydroxy alkenes to ω-lactones in good yields with the net loss of one or more carbon atoms in the procees.
- Baskaran, Sundarababu,Islam, Imadul,Vankar, Padma S.,Chandrasekaran, Srinivasan
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p. 1670 - 1671
(2007/10/02)
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- Heteroatom containing perfluoroalkyl terminated neopentyl glycols and compositions therefrom
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Heteroatom containing perfluoroalkyl terminated neopentyl glycols of the formulas HO[--CH2 C(CH2 X--E--Rf)2 CH2 O]1-3 --H or HO[--CH2 C(CH2 X--Rf)2 CH2 O]1-3 --H are prepared from halogenated neopentyl glycols or oxetanes and thiols of the formula Rf --E--SH, amines of the formuls Rf --E--NH--R, alcohols of the formula Rf --E--OH or perfluoro-amides, wherein Rf is a straight or branched chain perfluoroalkyl of 1 to 18 carbon atoms or said perfluoroalkyl substituted by perfluoroalkoxy of 2 to 6 carbon atoms. The polymeric reaction products of said fluorinated diols, and optionally other diols with isocyanates to prepare polyurethanes; with amines and isocyanated to prepare polyureas/polyurethanes; with acids or derivatives to prepare polyesters or polycarbonates are disclosed. These include polymeric, random or block urethane, and/or urea, and/or ester compositions containing the residue of at least one Rf -neopentyl glycol containing two perfluoroalkyl hetero groups. These polymeric compositions provide improved thermal stability and useful low surface energy oil and water repellent coatings, and soil-release properties for textiles, glass, paper, leather and other materials.
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- On the Mechanism of the Baeyer-Villiger Oxidation of Ketones by Bis(trimethylsilyl) Peroxomonosulfate. Intermediacy of Dioxiranes
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The Baeyer-Villiger oxidation of cyclohexanone (2a) and of acetophenone (2b) by bis(trimethylsilyl)peroxomonosulfate (1) has been reinvestigated using (18)O-labeling techniques.Starting with doubly labeled Me3Si(18)O(18)OSO3SiMe3, mass spectrometric analyses allowed determination of the amount of label appearing in the carbonyl and the OR moiety of the ester (or of the lactone).It has been observed that 2a also promotes the decomposition of 1 to yield oxygen gas, which was analyzed for its (18)O content.Furthermore, ketones 2a, 4-heptanone, and acetone were foundto enhance significantly the rate of oxidation of 1-methylcyclohexene (10) and of trans-β-methylstyrene (13) by 1, yielding 2-methylcyclohexanone (12) and 1-phenylpropanone (15) derived from the isomerization of the initially formed epoxides.These observations, most notably the (18)O-tracer results, point to a mechanism involving the intermediacy of dioxiranes as the prevailing pathway.
- Camporeale, Michele,Fiorani, Tiziana,Troisi, Luigino,Adam, Waldemar,Curci, Ruggero,Edwards, John O.
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- A NEW FATTY ACID METHYL ESTER AND OTHER BIOLOGICALLY ACTIVE COMPOUNDS FROM ASPERGILLUS NIGER
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Methyl 3-methyl-8-hydroxy-4-decenoate, a new C10 fatty acid methyl ester, was isolated and characterized from Aspergillus niger var.Tieghem.The chemical synthesis of this compound has also been achieved.Other compounds characterized from A. niger were phenylethanol, phenylacetic acid, phenoxyacetic acid, p-methoxyphenylacetic acid, mannitol and citric acid.All compounds except mannitol, inhibited the germination of cress and lettude seeds.Antifungal bioassay of the above compounds on Cladosporium herbarum showed activity except for the C10 fatty acid methyl ester, mannitol and citric acid.Key Word Index - Aspergillus niger; fungus; methyl 3-methyl-8-hydroxy-4-decenoate; phenylethanol; phenylacetic acid; phenoxyacetic acid; p-methoxyphenylacetic acid; mannitol; citric acid.
- Nair, Muraleedharan G.,Burke, Basil A.
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p. 3169 - 3174
(2007/10/02)
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- A Convenient Reduction Method of β-Phenyl α,β-Unsaturated Carbonyl Compounds with Me3SiCl-NaI-ROH Reagent
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Treatment of β-phenyl α,β-unsaturated ketones, cinnamic acid and its ester with Me3SiCl-NaI-ROH reagent in hexane at room temperature gave the corresponding saturated carbonyl compounds in good yileds.A similar reaction of 2,4-hexadienoic acid afforded 4-hexanolide.
- Sakai, Takashi,Miyata, Kazuyoshi,Utaka, Masanori,Takeda, Akira
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p. 1063 - 1066
(2007/10/02)
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- γ-Substituted Butyrolactones from Acrolein and Carbonyl Compounds
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The lithiation of 3-chloropropanal diethyl acetal (easily prepared from acrolein) at -78 deg C with lithium naphthalenide followed by reaction with various carbonyl compounds, and final oxidation with m-chloroperbenzoic acid leads to γ-susbstituted butyrolactones.
- Barluenga, Jose,Fernandez, Jose R.,Yus, Miguel
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p. 1534 - 1535
(2007/10/02)
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- SYNTHESE VON γ-HYDROXYNITRILEN, γ-BUTYROLACTONEN UND α-METHYLENO-γ-BUTYROLACTONEN AUS EPOXIDEN UND NATRIUM-
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The highly nucleophilic ylide-anion of sodium- attacks oxiranes by ring-opening.Depending on the work-up-conditions and the further reactions being employed, γ-hydroxynitriles, γ-butyrolactones or α-methyleno-γ-butyrolactones are obtained from the primary products thus formed.
- Bestmann, Hans Juergen,Schmidt, Martin
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p. 2111 - 2114
(2007/10/02)
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- SUBSTITUENT DIRECTED OXIDATIVE CYCLIZATION WITH CETYLTRIMETHYLAMMONIUM PERMANGANATE: A GENERAL APPROACH TO THE SYNTHESIS OF γ- AND δ-LACTONES
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Treatment of primary, secondary or tertiary γ- and δ-hydroxyolefins with cetyltrimethylammonium permanganate gives good yields of γ- and δ-lactones by oxidative cyclization, with loss of one carbon.
- Rathore, Rajendra,Vankar, Padma S.,Chandrasekaran, S.
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p. 4079 - 4082
(2007/10/02)
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- A HIGHLY EFFICIENT SYNTHESIS OF γ- AND δ-LACTONES BY OXIDATIVE CYCLIZATION
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Treatment of tertiary γ- and δ-hydroxyolefins with pentavalent chromium reagent, (BipyH2)CrOCl5, give good yields of γ- and δ-lactones by oxidative cyclization, with loss of one carbon.Pyridinium chlorochromate (PCC) also effect this transformation to γ-lactones in reasonable yields.
- Chakraborty, T. K.,Chandrasekaran, S.
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p. 551 - 554
(2007/10/02)
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- Anodic Oxidation of Cyclohexanone on Lead Dioxide Electrode in Aqueous Sulfuric Acid Solution
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The electrolytic behavior of cyclohexanone was examined by potentiometry with rotating disk electrode as well as by product analyses.The reaction was activation controlled and the reaction orders were first with respect to cyclohexanone and zero for proton.Cyclohexanone reacted by approximately 6 electrons to give adipic acid mainly which accumulated proportionally to the electricity consumed.Changes in temperature, proton concentration, and current denisty resulted in only minor effects on the reaction.In neutral solution, however, the oxidation was suppressed and oxygen evolution dominated.Other electrode materials such as Pt, graphite, RuO2, and PtO2 were inactive.The chemical oxidation with PbO2 itself did not occur.From these facts, reaction mechanism was discussed.
- Kunai, Atsutaka,Hatoh, Kazuhito,Hirano, Yoshinobu,Harada, Junji,Sasaki, Kazuo
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p. 1717 - 1722
(2007/10/02)
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- Synthesis of γ- and δ-Lactones via Radical CC-Bond Formation Reaction
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Lactones 5 and 6 can be synthesized via solvomercuration of alkenes 1 and reductive CC-bond formation with acrylonitrile.
- Giese, Bernd,Hasskerl, Thomas,Luening, Ulrich
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p. 859 - 861
(2007/10/02)
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- Synthesis of Racemates and (+)-Enantiomers of γ-Caprolactone, γ-Dodecanolactone and δ-Hexadecanolactone, Lactonic Sex Pheromones of the Dermestid Beetle, Rove Beetle and Oriental Hornet
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A simple method based on regioselective two-step alkylation of easily-available diethyl 3-oxoglutarate (2) is described for the synthesis of racemates of the lactonic pheromones, 1a, 1b, and 1c.Their (+)-enantiomers were also synthesized by means of microbiological reduction of the intermediary keto acids.
- Naoshima, Yoshinobu,Ozawa, Hiroshi,Kondo, Hirokiyo,Hayashi, Shuichi
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p. 1431 - 1434
(2007/10/02)
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- Direct Oxidation of Alkanoic Acids and their Amides to γ-Lactones by Peroxydisulphate-containing Systems
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The reaction of one-electron oxidation of alkanoic acids (I) and their amides (VI) on treatment with Na2S2O8-containing systems has been studied.As a result of the direct one-pot reaction acids (I) and amides (VI) are converted into γ and δ-lactones, the reaction being regioselective and leading mainly to γ-lactones in up to 35percent yield.The regioselectivity of the oxidative lactonisation depends greatly on the nature of alkyl substituents.The results obtained are presented in terms of a mechanism suggesting the generation of acyloxyl and amidyl radicals from (I) and (VI), respectively, followed by a rearrangement via a 1,5- or 1,6-H shift into the corresponding 3- and 4-carboxy- or -carboxamido-alkyl ra The latter undergo oxidative cyclisation to produce γ and δ lactones.The system Na2S2O8-NaCl-NaOH converts carboxamides (VI) into amines with loss of one carbon atom as a result of a Hoffmann type rearrangement.
- Nikishin, Gennady I.,Svitanko, Igor V.,Troyansky, Emmanuil I.
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p. 595 - 602
(2007/10/02)
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- THE SYNTHESIS OF NATURALLY OCCURRING 4-ALKYL- AND 4-ALKENYL-γ-LACTONES USING THE ASYMMETRIC REDUCING AGENT B-3-PINANYL-9-BORABICYCLONONANE
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4-Hydroxy-2-alkynoates of high enantiomeric purity, available from the reduction of the corresponding ketones with B-3-pinanyl-9-BBN, are converted to 4-substituted-γ-lactones found in beetle and deer pheromones.
- Midland, M. Mark,Tramontano, Alfonso
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p. 3549 - 3552
(2007/10/02)
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