- One-pot method for preparing diepoxide (by machine translation)
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The method comprises the following steps, adding a reducing agent water solution :S1. to a reactor: slowly dropwise adding a reducing agent aqueous solution to obtain the diepoxide, adding a reducing agent aqueous solution to the reactor, to obtain the diepoxy, and separating and purifying ;S2. from the organic phase: by one-pot reaction, and adding a reducing agent water, through a pot method to obtain the diepoxide crude solution, to obtain the diepoxide compound. The invention discloses a method for separating and purifying a diepoxide crude product through a high vacuum, distillation . The method comprises the following steps of: adding a reducing agent aqueous solution to the, reactor at a low temperature, to obtain a diepoxide 91% crude, product through 95% a, one-pot reaction, of the diolefin and the m-chloroperoxybenzoic acid solution to obtain a diepoxide crude product solution. (by machine translation)
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Paragraph 0077-0084
(2020/05/01)
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- NOVEL BETA-HYDROXYLATED TERTIARY DIAMINES, A PROCESS FOR THEIR SYNTHESIS AND THEIR USE FOR ELIMINATING ACID COMPOUNDS A GASEOUS EFFLUENT
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The invention relates to novel nitrogen compounds belonging to the family of tertiary diamines of general formula (I) below, wherein R is an alkanediyl radical —(CH2)n- with n=2, 3, 4, 5 or 6. The compound according to the invention is for example N,N,N′,N′-(tetramethyl)-1,6-diamino-2,5-hexanediol or N,N,N′,N′-(tetramethyl)-1,8-diamino-2,7-octanediol. The invention also relates to the method for preparing them and to their use for removing acid compounds contained in a gaseous effluent.
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Paragraph 0143; 0144; 0145; 0146; 0147; 0148; 0149
(2017/04/11)
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- AMINOMETHYL- AND METHYLOXY-LINKED TRICYCLIC COMPOUNDS AS INHIBITORS OF PROTEIN AGGREGATION
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The present invention relates to certain aminomethyl- and methyloxy-linked tricyclic compounds, pharmaceutical compositions containing them, and methods of using them, including methods for preventing, reversing, slowing, or inhibiting protein aggregation, and methods of treating diseases that are associated with protein aggregation, including neurodegenerative diseases such as Parkinson's disease, Alzheimer's disease, Lewy body disease, Parkinson's disease dementia, fronto-temporal dementia, Huntington's Disease, amyotrophic lateral sclerosis, and multiple system atrophy.
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Paragraph 0085
(2016/06/01)
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- Chiral Pool/Henry/Enzymatic routes to acetogenin synthons
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Enantio specific and enantioselective approaches to the natural (16 R,19R)- and the unnatural (16S,19S)- THF core of the bioactive acetogenin annonacin are described which utilizes both a chiral pool synthesis and enzymatic transformations. In the antipodal (2S,5S) THF series derived from D-(+)-glucosamine, the semi-protected THF aldehyde synthon allows for two-directional synthetic elaboration through a Henry reaction with a lipid-like nitroalkane. The resulting nitroalcohol having the unnatural (2S,5S)-THF core was oxidized to the corresponding a-nitroketone using a modified Collins oxidation. The intermediate a-nitroketone has potential for the preparation of the C15-C32 core and analogues through subsequent removal of the nitro group and reduction of the carbonyl.
- Qayed, Wesam S.,Luzzio, Frederick A.
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p. 622 - 630
(2015/11/09)
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- Coordination of new disulfide ligands to CuIand CuII: Does a CuII μ-thiolate complex form?
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Interest in dinuclear CuII μ-thiolate and CuI disulfide complexes is triggered by their similarity with the CuA site and the possibility to control this redox equilibrium. Three new disulfide ligands L1, L3 and L4 were synthesized and reacted with CuI salts to investigate whether thiolate or disulfide species would form. The nature of L1 precludes the formation of CuII μ-thiolate species, resulting in the formation of [Cu2I(L1)(CH3CN)](BF4)2 which was characterized via single crystal X-ray crystallography. Pyrazole-containing ligands L3 and L4 form CuI complexes that are stable in solution in air for hours with half-wave potentials of approximately +0.55 V versus Ag/AgCl, indicating high stability of the CuI state rather than the CuII state. The half-wave potentials of the CuI complexes with L1 and L2 are less positive, indicating that in order to allow formation of both CuII μ-thiolate and CuI disulfide species, a half-wave potential of roughly 0 V versus Ag/AgCl would be ideal. Furthermore, CuII crystal structures with L1, L2, L3 and L4 and different counterions were compared and analyzed. Pyrazolyl-containing ligands L3 and L4 form complexes that are very similar to the complexes with pyridyl-containing ligands L1 and L2.
- Ording-Wenker, Erica C. M.,Siegler, Maxime A.,Bouwman, Elisabeth
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supporting information
p. 193 - 202
(2015/03/04)
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- Bioproduction of chiral epoxyalkanes using styrene monooxygenase from rhodococcus sp. ST-10 (RhSMO)
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We describe the enantioselective epoxidation of straight-chain aliphatic alkenes using a biocatalytic system containing styrene monooxygenase from Rhodococcus sp. ST-10 and alcohol dehydrogenase from Leifsonia sp. S749. The biocatalyzed enantiomeric epoxidation of 1-hexene to (S)-1,2-epoxyhexane (44.6 mM) using 2-propanol as the hydrogen donor was achieved under optimized conditions. The biocatalyst had broad substrate specificity for various aliphatic alkenes, including terminal, internal, unfunctionalized, and di- and tri-substituted alkenes. Here, we demonstrate that this biocatalytic system is suitable for the efficient production of enantioenriched (S)-epoxyalkanes.
- Toda, Hiroshi,Imae, Ryouta,Itoh, Nobuya
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p. 3443 - 3450
(2015/02/05)
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- C-TERMINAL HSP90 INHIBITORS
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Hsp90 C-terminal inhibitors and pharmaceutical compositions containing such compounds are provided. The compounds of the disclosure are useful for the treatment and/or prevention of neurodegenerative disorders such as diabetic peripheral neuropathy.
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Paragraph 00350; 00351
(2013/08/28)
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- Absolute configuration for 1, n-glycols: A nonempirical approach to long-range stereochemical determination
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The absolute configurations of 1,n-glycols (n = 2-12, 16) bearing two chiral centers were rapidly determined via exciton-coupled circular dichroism (ECCD) using a tris(pentafluorophenyl)porphyrin (TPFP porphyrin) tweezer system in a nonempirical fashion devoid of chemical derivatization. A unique "side-on" approach of the porphyrin tweezer relative to the diol guest molecule is suggested as the mode of complexation.
- Li, Xiaoyong,Burrell, Carmin E.,Staples, Richard J.,Borhan, Babak
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supporting information; experimental part
p. 9026 - 9029
(2012/07/13)
-
- Regioselective epoxidation of different types of double bonds over large-pore titanium silicate Ti-β
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Regioselective epoxidation of different types of double bonds located within the cyclic and acyclic parts of bulky olefins has been investigated using large-pore titanium silicate Ti-β in the presence of dilute aqueous H 2O2 as oxidant under mild liquid-phase conditions. Our experimental results revealed that side-chain vinylic double bonds are selectively epoxidized than those in the cyclohexene-ring. The epoxidation tendency of various bulky olefins with different positional and/or geometric isomers over Ti-β follows the order: terminal -CC- > ring -CC- ≈ bicyclic ring -CC- > allylic C - H bond. Unlike 4-vinyl-1-cyclohexene, epoxidation of an equimolar mixture of cyclohexene and 1-hexene under identical conditions using Ti-β exhibits completely different selectivity and product distributions. Steric factor and accessibility of reactants to active Ti-sites are responsible for the observed regioselectivity of bulky alkenes.
- Sasidharan, Manickam,Bhaumik, Asim
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experimental part
p. 60 - 67
(2010/12/18)
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- Regioselectivity and diasteroselectivity in Pt(II)-mediated "green" catalytic epoxidation of terminal alkenes with hydrogen peroxide: Mechanistic insight into a peculiar substrate selectivity
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Recently developed electron-poor Pt(II) catalyst 1 with the "green" oxidant 35% hydrogen peroxide displays high activity and complete substrate selectivity in the epoxidation of terminal alkenes because of stringent steric and electronic requirements. In the presence of isolated dienes bearing terminal and internal double bonds, epoxidation is completely regioselective toward the production of terminal epoxides. Insight into the mechanism is gained by means of a reaction progress kinetic analysis approach that underlines the peculiar role of 1 in activating both the alkene and H 2O2 in the rate-determining step providing a rare example of nucleophilic oxidation of alkenes by H2O2.
- Colladon, Marco,Scarso, Alessandro,Sgarbossa, Paolo,Michelin, Rino A.,Strukul, Giorgio
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p. 7680 - 7689
(2008/02/05)
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- 7-N,7′,N′-(1″,2″-Dithianyl-3″, 6″-dimethylenyl)bismitomycin C: Synthesis and nucleophilic activation of a dimeric mitomycin
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Dimeric alkylating agents that modify complementary DNA strands have engendered significant interest. We have prepared the novel dimeric mitomycin, 7-N,7′-N′-(1″,2″-dithianyl-3″,6″- dimethylenyI)bismitoinycin C (9), in which the mitomycins are bridged by a dithiane unit. Dimer 9, like the clinically tested acyclic disulfides KW-2149 (3) and BMS-181174 (4), was designed to activate under nucleophilic and reductive conditions. Successive nucleophile-mediated disulfide cleavage transformations of 9 are expected to generate thiol species ideally positioned to render the two mitomycin systems vulnerable to nucleophilic attack and permit DNA interstrand cross-link formation. The dithiane linker, strategically positioned between the two mitomycins, distinguished 9 from 3 and 4. Nucleophilic activation of this cyclic disulfide permitted both activated mitomycins to remain tethered to one another. We report the synthesis of 9, and show that the nucleophile Et,P markedly enhances the activation and consumption of 9, compared with the reference compound 7-N, 7′-N′-(cyclohexanyl- trans-1″,4″-duiiethylenyl)bismitomycin C (27). We further demonstrated that 9 provides higher levels of DNA interstrand cross-links than either the dimeric reference compounds, 27 and 7-N,7-N′-(2″, 5″-dihydroxy-1″,6″-hexanediyl)bismitomycin C (28), or the monomeric mitomycins, 1 and 3, when Et3P is added to solutions containing EcoRI-linearized pBR322 DNA.
- Lee, Sang Hyup,Kohn, Harold
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p. 471 - 482
(2007/10/03)
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- C2-symmetric enantiopure ethanotethered bis(α,β-butenolides) as templates for asymmetric synthesis. Application to the synthesis of (+)-grandisol
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Starting from D-mannitol, we have prepared several C2-symmetric ethanotethered bis(α,βbutenolides) and studied their [2+2] photocycloaddition reaction with ethylene. The protective groups of the central diol unit have a noticeable influence on the facial selectivity of the cycloaddition, the bis(trimethylsilyloxy) derivatives showing the highest diastereoselectivity. A theoretical conformational analysis of the substrates in the ground state is in good agreement with the diastereofacial selectivity experimentally observed. The bis(photocycloadducts) have been converted into the enantiopure cyclobutanes formally derived from the photoreaction of ethylene with γ-0hydroxymethylα,β-butenolide, in which only a moderate facial selectivity had been previously found. As an application of these studies, we have developed a highly efficient and stereoselective synthesis of (+)-grandisol.
- De March, Pedro,Figueredo, Marta,Font, Josep,Raya, Javier,Alvarez-Larena, Angel,Piniella, Juan F.
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p. 2437 - 2447
(2007/10/03)
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- Homologation of allylic alcohols. An approach to cyclic and acyclic polyoxygenated compounds
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The combination of the Sharpless asymmetric epoxidation reaction with a sulfur ylide mediated synthesis of allylic alcohols from epoxides provides a powerful iterative process for the production of polyoxygenated compounds. The alkene installed in the sulfur ylide reaction has also been used in a number of ring closing metathesis reactions to produce highly oxygenated cyclic compounds. (C) 2000 Elsevier Science Ltd.
- Davoille, Ryan J.,Rutherford, David T.,Christie, Steven D. R.
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p. 1255 - 1259
(2007/10/03)
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- 1,2,5,6-Diepoxyhexane and 1,2,7,8-diepoxyoctane cross-link duplex DNA at 5'-GNC sequences
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The carcinogenicity of epoxide compounds has been attributed to covalent binding to DNA. Whereas monoepoxides form only monoadducts, diepoxides can form both monoadducts and interstrand cross-links. The latter are believed to be the more significant cytotoxic lesions as diepoxides are frequently more carcinogenic and mutagenic than their monoepoxide analogues. We therefore examined the relative DNA interstrand cross-linking capabilities of several diepoxides with respect to chain length, molecular flexibility, reported carcinogenic potential, and DNA sequences targeted. Using denaturing polyacrylamide gel electrophoresis, we found that 1,2,5,6- diepoxyhexane and 1,2,7,8-diepoxyoctane share the 5'-GNC target sequence previously found for 1,2,3,4-diepoxybutane [Millard, J. T., and White, M. M. (1993) Biochemistry 32, 2120-2124] and that the efficiency of cross-linking this sequence may reflect carcinogenicity. 1,2,5,6-Diepoxycyclooctane, the biologically inactive rigid analogue of 1,2,5,6-diepoxyhexane, was found to be a poor cross-linker of all DNA sequences examined. Moreover, increasing the diepoxyalkane chain length did not result in enhanced cross-linking ability.
- Yunes, Michael J.,Charnecki, Sara E.,Marden, Jennifer J.,Millard, Julie T.
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p. 994 - 1000
(2007/10/03)
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- Improved syntheses of both enantiomers of 1,2,5,6-diepoxyhexane from (2S,5S)-1,2,5,6-hexanetetrol
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Several methods for the preparation of (2R,5R)- and (2S,5S)-1,2,5,6-diepoxyhexane (2) from 3,4-dideoxy-D-threo-hexitol [(2S,5S)-1,2,5,6-hexanetetrol (1)] as a single common chiral synthon are described. Among these methods, the methods via (2S,5S)-1,6-bis(pivaloyloxy)-2,5-hexanediol and (2S,5S)-2,5-bis(benzoyloxy)-1,6-dibromohexane, both derived from 1, provide the best results in terms of the selectivity, yield, and optical purity for the preparation of (R,R)-2 and (S,S)-2, respectively.
- Machinaga,Kibayashi
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p. 989 - 994
(2007/10/02)
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- General Entry to the 3,5-Disubstituted Indolizidine Class of Dendrobatid Alkaloids. Total Syntheses of Both Enantiomers of Indolizidines 195B, 223AB, 239AB, and 239CD from a Common Chiral Synthon
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A general protocol for the total syntheses of both enantiomers of dendrobatid alkaloids, indolizidines 195B, 223AB, 239AB, and 239CD, belonging to the 3,5-disubstituted indolizidine subclass is described, in which 3,4-dideoxy-D-threo-hexitol (8) has been used as single and common chiral synthon.The syntheses of the (+)- and (-)-enantiomers of these alkaloids begin with (S,S)- and (R,R)-1,2:5,6-diepoxyhexanes (7), respectively, both of which were derived from 8 in three steps and are carried out by way of pyrrolidine formation via the cyclic sulfates leading to the(2R,5R)- and (2S,5S)-trans-2,5-dialkylated pyrrolidines, which were converted to the (+)- and (-)-enantiomers, respectively, of the title indolizidine alkaloids.These syntheses involve the first chiral preparations of indolizidines 239AB, 239CD both in natural (-)- and unnatural (+)-enantiomeric forms, which confirm the absolute configurations of natural 239AB and 239CD as 3R,5S,8aR and 3R,5R,8aR, respectively.
- Machinaga, Nobuo,Kibayashi, Chihiro
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p. 5178 - 5189
(2007/10/02)
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- Enantioselective Total Synthesis of (+)- and (-)-Pyrrolidine 197B, a New Class of Alkaloid from the Dendrobatid Poison Frog: Assignment of the Absolute Configuration
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Enantioselective total synthesis of both enantiomers of pyrrolidine 197B (1), a new class of dendrobatid alkaloid, is described.The synthesis begins with the C2 symmetric S,S or R,R diepoxides 4, derived from (S,S)-1,2,5,6-hexanetetraol (2) as a single common chiral synthon, and involves pyrrolidine formation via the cyclic sulfonates to afford (+)- or (-)-1, respectively.The (+) and (-) enantiomers of 1 were converted to the corresponding N-benzoyl derivatives (+)-27 and (-)-27, which were directly compared with 27 derived from natural 1 by HPLC using a Chiracel column.This comparison established the absolute stereochemistry of the natural enantiomer of pyrrolidine 197B as 2S,5S.
- Machinaga, Nobuo,Kibayashi, Chihiro
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p. 1386 - 1393
(2007/10/02)
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- ENANTIODIVERGENT TOTAL SYNTHESIS OF NATURALLY OCCURING trans-2-BUTYL-5-PENTYLPYYROLIDINE
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The enantiodivergent total synthesis of (+)-(2S,5S)- and (-)-(2R,5R)-trans-2-butyl-5-pentylpyrrolidines was effected from the C2 symmetric (S,S)- and (R,R)-diepoxides, respectively, both prepared from D-mannitol, by a sequence involving stereo-defined ring construction of the unsymmetrical trans-2,5-dialkylpyrrolidine via the cyclic sulfate as a key step.
- Machinaga, Nobuo,Kibayashi, Chihiro
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p. 3637 - 3640
(2007/10/02)
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- Anti-arrhythmia agents
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Acetamide derivatives are provided having the structure STR1 wherein X is a single bond, --CH2 -- or --O--, R1 and R2 may be the same or different and are lower alkyl, phenyl-lower alkoxy-lower alkyl, lower alkenyl, phenyl-lower alkyl or lower alkoxy, or STR2 may be taken together to form a 5- to 7-membered heterocyclic ring optionally containing one other hetero atom, such as nitrogen, sulfur or oxygen; Y is hydroxyl, OR wherein R is lower alkyl, lower alkenyl or lower alkanoyl, or STR3 wherein R1 and R2, and R1 and R2 taken together with the nitrogen to which they are attached are as defined above, and n is 1 to 6. These compounds are useful as anti-arrhythmia agents and have been found to be effective in the treatment of acute myocardial infarction.
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- Rate Constants and Equilibrium Constants for Thiol-Disulphide Interchange Reactions Involving Oxidized Glutathione
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The rate of reduction of oxidized glutathione (GSSG) to glutathione (GSH) by thiolate (RS-) follows a Broensted relation in pKas of the conjugate thiols (RSH): βnuc ca. 0.5.This value is similar to that for reduction of Ellman's reagent: βnuc ca. 0.4 - 0.5.Analysis of a number of rate and equilibrium data, taken both from this work and from the literature, indicates that rate constants, k, for a range of thiolate-disulphide interchange reactions are correlated well by equations of the form log k = C + βnucpKanuc + βcpKac + βlgpKalg ( nuc = nucleophile, c = central, and lg = leaving group sulfur): eq 36 - 38 give representative values of the Broensted coefficients.The values of these Bronsted coefficients are not sharply defined by the available experimental data, although eq 36 - 38 provide useful kinetic models for rates of thiolate-disulfide interchange reactions.The uncertainty in these parameters is such that their detailed mechanistic interpretation is not worthwhile, but their qualitative interpretation - that all three sulphur atoms experience a significant effective negative charge in the transition state, but that the charge is concentrated on the terminal sulfurs - is justified.Equilibrium constants for reduction of GSSG using α,ω-dithiols have been measured.The reducing potential of the dithiol is strongly influenced by the size of the cyclic disulfide formed on its oxidation: the most strongly reducing dithiols are those which can form six-membered cyclic disulfides.Separate equilibrium constants for thiolate anion-disulphide interchange (KS-) and for thiol-disufide interchange (KSH) have been estimated from literature data: KS- is roughly proportional to 2ΔpKa is the difference between the pKas of the two thiols involved in the interchange.The contributions of thiol pKa values to the observed equilibrium constants for reduction of GSSG with α,ω-dithiols appear to be much smaller than those ascribable to the influence of structure on intramolecular ring formation.These equilibrium and rate constants are helpful in choosing dithiols for use as antioxidants in solutions containing proteines: dithiothreitol (DTT), 1,3-dimercapto-2-propanol (DMP), and 2-mercaptoethanol have especially useful properties.
- Szajewski, Richard P.,Whitesides, George M.
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p. 2011 - 2026
(2007/10/02)
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- Process for preparing aldehydes from oxirane compounds
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Aldehydes are prepared by reacting an oxirane compound with hydrogen peroxide in the presence of a boron compound.
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