- Tetrahydro-4 H-pyran-4-one: From the Laboratory Scale to Pilot Plant Manufacture
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This study describes our recent efforts to find an efficient and scalable route to tetrahydro-4H-pyran-4-one using the commercially available starting materials. The route scouting work and the full development of an efficient access to the target are described. This work culminated in the preparation of above 20 kg of the title compound in our pilot plant facility.
- Bergraser, Julie,Berranger, Thierry,Carlier, Agathe,Delacroix, Kenny,Echeverria, Pierre-Georges,Petit, Laurent,Zahim, Sara
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supporting information
(2022/01/12)
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- Cobalt-Catalyzed Aerobic Oxidative Cleavage of Alkyl Aldehydes: Synthesis of Ketones, Esters, Amides, and α-Ketoamides
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A widely applicable approach was developed to synthesize ketones, esters, amides via the oxidative C?C bond cleavage of readily available alkyl aldehydes. Green and abundant molecular oxygen (O2) was used as the oxidant, and base metals (cobalt and copper) were used as the catalysts. This strategy can be extended to the one-pot synthesis of ketones from primary alcohols and α-ketoamides from aldehydes.
- Li, Tingting,Hammond, Gerald B.,Xu, Bo
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supporting information
p. 9737 - 9741
(2021/05/31)
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- Tetrahydropyranone preparation method
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The invention relates to a tetrahydropyranone preparation method, the method takes acetone and diethyl oxalate as raw materials, through steps of a ring closure reaction, a decarboxylation reaction, and a reduction reaction, three-step high-yield synthesis is realized to obtain tetrahydropyranone. The tetrahydropyranone preparation method has the advantages of high yield, low cost, and easy operation, and is suitable for industrial preparation method.
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Paragraph 0017; 0022
(2018/10/11)
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- Synthetic method of medical intermediate tetrahydropyran-4-one
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The invention discloses a synthetic method of a medical intermediate tetrahydropyran-4-one. The synthetic method of comprises the following steps: dissolving bis(2-chloroethyl)ether in ethanol, addinga Zr-Ce-Ti-Al compound oxide and ruthenium iodide, carrying out heating to 70-90 DEG C, adding H2O, introducing CO2 under a stirring condition, controlling the pressure to be 1.1-1.6 MPa, carrying out cooling to room temperature after the reaction is completed, carrying out filtering, carrying out reduced pressure distillation to remove the ethanol and the H2O, and carrying out recrystallizing toobtain the tetrahydropyran-4-one. The synthesis method provided by the invention is simple in operation, mild in conditions and few in by-products, the product purity is high, and the product yield is high.
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Page/Page column 4-6
(2019/01/06)
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- Synthesis of azasilacyclopentenes and silanols: Via Huisgen cycloaddition-initiated C-H bond insertion cascades
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An unusual transition metal-free cascade reaction of alkynyl carbonazidates was discovered to form azasilacyclopentenes. Mild thermolysis afforded the products via a series of cyclizations, rearrangements, and an α-silyl C-H bond insertion (rather than the more common Wolff rearrangement, 1,2-shift, or β-silyl C-H insertion) to form silacyclopropanes. A mechanistic proposal for the sequence was informed by control experiments and the characterization of reaction intermediates. The substrate scope and post-cascade transformations were also explored.
- Shih, Jiun-Le,Jansone-Popova, Santa,Huynh, Christopher,May, Jeremy A.
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p. 7132 - 7137
(2017/10/05)
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- New acyloxy nitroso compounds with improved water solubility and nitroxyl (HNO) release kinetics and inhibitors of platelet aggregation
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New acyloxy nitroso compounds, 4-nitrosotetrahydro-2H-pyran-4-yl 2,2,2-trichloroacetate and 4-nitrosotetrahydro-2H-pyran-4-yl 2,2-dichloropropanoate were prepared. These compounds release HNO under neutral conditions with half-lives between 50 and 120 min, identifying these HNO donors as kinetically intermediate to the much slower acetate derivative and the faster trifluoroacetic acid derivative. These compounds or HNO-derived from these compounds react with thiols, including glutathione, thiol-containing enzymes and heme-containing proteins in a similar fashion to other acyloxy nitroso compounds. HNO released from these acyloxy nitroso compounds inhibits activated platelet aggregation. These acyloxy nitroso compounds augment the range of release for this group of HNO donors and should be valuable tools in the further study of HNO biology.
- Mohamed, Heba A.H.,Abdel-Aziz, Mohamed,Abuo-Rahma, Gamal El-Din A.A.,King, S. Bruce
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p. 6069 - 6077
(2015/11/10)
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- Rate coefficients for the gas-phase reactions of chlorine atoms with cyclic ethers at 298 K
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Rate coefficients of reactions of Cl atoms with cyclic ethers, tetrahydropyran (THP), tetrahydrofuran (THF), and dihydrofurans (2,5-DHF and 2,3-DHF) have been measured at 298 K using a relative rate method. The relative rate ratios for THP and THF are 0.80 ± 0.05 and 0.80 ± 0.08, respectively, with n-hexane as the reference molecule. The relative rate ratios for THF and 2,5-DHF with n-pentane as the reference molecule are 0.95 ± 0.07 and 1.73 ± 0.06, respectively, and for 2,5-DHF with 1-butene as reference is 1.38 ± 0.05. The average values of the rate coefficients are (2.52 ± 0.36), (2.50 ± 0.39), and (4.48 ± 0.59) × 10-10 cm3 molecule-1 s-1 for THP, THF, and 2,5-DHF, respectively. The errors quoted here for relative rate ratios are 2σ of the statistical variation in different sets of experiments. These errors, combined with the reported errors of the reference rate coefficients using the statistical error propagation equation, are the quoted errors for the rate coefficients. In the case of 2,3-DHF, after correcting for the dark reaction with CH3COCl and assuming no interference from other radical reactions, a relative rate ratio of 0.85 ± 0.16 is obtained with respect to cycloheptene, corresponding to a rate coefficient of (4.52 ± 0.99) × 10-10 cm3 molecule-1 s-1. Unlike cyclic hydrocarbons, there is no increase with increasing number of CH2 groups in these cyclic ethers whereas there is an increase in the rate coefficient with unsaturation in the ring. An attempt is also made to correlate the rate coefficients of cyclic hydrocarbons and ethers with the molecular size as well as HOMO energy.
- Alwe,Walawalkar,Sharma,Pushpa,Dhanya,Naik
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p. 295 - 305
(2013/08/25)
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- PROCESSES FOR PRODUCING TETRAHYDROPYRAN-4-ONE AND PYRAN-4-ONE
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The present invention relates to a process for preparing tetrahydropyran-4-one represented by the formula (1): which comprises reacting at least one kind of dihydropyran-4-one and pyran-4-one represented by the formula (2): wherein represents a single bond or a double bond, and hydrogen (a) in the presence of a metal catalyst, in a mixed solvent of an aprotic solvent and an alcohol solvent, or (b) in the presence of an anhydrous metal catalyst in which a hydrated metal catalyst is subjected to dehydration treatment, in a hydrophobic organic solvent.
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Page/Page column 13
(2010/11/23)
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- Regiochemical control of the ring opening of 1,2-epoxides by means of chelating processes. Part 15: Regioselectivity of the opening reactions with MeOH of remote O-substituted regio- and diastereoisomeric pyranosidic epoxides under condensed- and gas-phase operating conditions
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The regiochemical behavior of pairs of regio- and diastereoisomeric epoxides derived from the 3,4,5,6-tetrahydro-2H-pyrane system, bearing an acetal group as the remote functionality, was determined in the acid methanolysis in the condensed phase (cd-phase) and in the reaction with MeOH in the gas-phase using a gaseous acid (D3+), as the promoting agent. With only one exception, the results obtained in the opening process of these epoxides indicate the incursion in the gas-phase of D+-mediated chelated bidentate species able to modify the regiochemical result found in the methanolysis in the cd-phase.
- Crotti, Paolo,Renzi, Gabriele,Favero, Lucilla,Roselli, Graziella,Di Bussolo, Valeria,Caselli, Micaela
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p. 1453 - 1467
(2007/10/03)
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- Aminooxyamide tricyclic inhibitors of farnesyl-protein transferase
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Novel aminooxyamide tricyclic compounds and pharmaceutical compositions are disclosed which are inhibitors of the enzyme, farnesyl protein transferase. Also disclosed is a method of inhibiting Ras function and therefore inhibiting the abnormal growth of cells. The method comprises administering the novel aminooxyamide tricyclic compound to a biological system. In particular, the method inhibits the abnormal growth of cells in a mammals such as a human.
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- Elemental fluorine. Part 7. New oxidation methodology
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Reaction of fluorine with water in the presence of acids provides new oxidants for 'in-situ' oxidation of ketones. Direct reaction of fluorine with anhydrous alcohols and 1,2-diols provides simple methodology for oxidation to corresponding secondary ketones or α-hydroxy ketones.
- Chambers, Richard D.,Hutchinson, John,Sandford, Graham,Shah, Aneela,Vaughan, Julian F. S.
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p. 15833 - 15842
(2007/10/03)
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- Phyllanthoside-Phyllanthostatin Synthetic Studies. 7. Total Synthesis of (+)-Phyllanthocin and (+)-Phyllanthocindiol
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A stereochemically linear total synthesis of (+)-phyllanthocin (5a), the aglycon methyl ester of the antineoplastic glycoside (+)-phyllanthoside (1), is described. The synthesis proceeds in 23 steps (4.5% overall yield) and affords (+)-phyllanthocin in high enantiomeric purity. The central features of the strategy include: (a) construction of aldehyde 8 via a stereoselective, intramolecular ene reaction; (b) elaboration of the spiroketal unit by a two-step tactic involving addition of a functionalized dihydropyran anion (i.e., 9) to 8, followed by a highly stereoselective spiroketalization; and (c) chemo- and stereoselective methylenation of the C(7) carbonyl group. In addition, a second-generation approach is presented, wherein an augmented spiroketalization maneuver not only establishes the C(8) spirocenter but also permits the regio- and stereocontrolled introduction of the C(11) methyl group. The latter sequence furnishes (+)-phyllanthocin in 21 steps (5.6% overall yield). Finally, the advanced phyllanthocin intermediate (+)-49 is converted in five steps (42% overall yield) to (+)-phyllanthocindiol (5b), the aglycon of phyllanthostatin 3.
- Smith III, Amos B.,Fukui, Mineo,Vaccaro, Henry A.,Empfield, James R.
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p. 2071 - 2092
(2007/10/02)
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- Syntheses and Equilibrations of 6- and 7-Carbomethoxy-trans-2-oxadecalins
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Syntheses of the title compounds based on a Robinson annulation scheme utilizing tetrahydropyran-4-one are described.The 6-substituted system is elaborated by using Wittig methodology, while the 7-substituted ester is prepared via regioselective enolate formation.The regioselectivity of the latter is verified by preparation of a 5-isomer by reductive carboxylation of the original annulation product.Base-catalyzed equilibrations indicate a slightly preference for the equatorial position than in the 2-decalyl analogue, with entropy contributing little to theconformational free energies.
- Anzalone, Luigi,Hirsch, Jerry A.
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p. 2607 - 2613
(2007/10/02)
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- Radical-cations of Aldehydes and Ketones generated by Ionizing Radiation: an Electron Spin Resonance Study
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Exposure of dilute solutions of various aldehydes and ketones in trichlorofluoromethane to 60Co γ-rays at 77 K gave, in most cases, the corresponding cations, identified by e.s.r. spectroscopy.The acetaldehyde cation is characterized by a very large proton hyperfine coupling, the SOMO being the in-plane, formally non-bonding, p-orbital on oxygen.At 77 K there was a weak interaction with one chlorine atom of a solvent molecule, but this was lost reversibly on annealing to ca. 120 K.That the quartet splitting was due to chlorine rather than to the methyl protons as had been previously supposed was established by studying the (CD3CDO(1+)) cation.The acetone cation spectrum comprised a single asymmetric feature with no evidence of solvent interaction or hyperfine coupling to the γ-protons.In contrast, aldehyde and ketone cations with δ-protons showed hyperfine coupling in the 10-30 G range to conformationally selected protons.For methyl groups, one proton only is selected, the coupling being lost reversibly on annealing.These findings are semi-quantitativelysupported by INDO calculations.
- Boon, Philip, J.,Symons, Martyn, C. R.,Ushida, Kiminori,Shida, Tadamasa
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p. 1213 - 1220
(2007/10/02)
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- A Versatile Synthesis of Four-, Five-, and Six-membered Cyclic Ketones Using Methyl Methylthiomethyl Sulfoxide
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Cyclization of 1,n-dihaloalkanes with methyl methylthiomethyl sulfoxide in the presence of a base (n-BuLi or KH) gave three-, four-, five-, and six-membered 1-methylsulfinyl-1-methylthiocycloalkanes.These cyclization products were easily converted to the corresponding ketones by acid hydrolysis except 1-methylsulfinyl-1-methylthiocyclopropane which afforded a complicated mixture.The combination of the cyclization with the acidhydrolysis thus provides a new method for synthesizing four-, five-, and six-membered cycloalkanones.Several representative preparations, such as those of substituted cyclobutanones, 3-cyclopentanone, and tetrahydro-4-pyrone are described.
- Ogura, K.,Yamashita, M.,Suzuki, M.,Furukawa, S.,Tsuchinashi, G.
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p. 1637 - 1642
(2007/10/02)
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