- The Separation of the Intramolecular Isotope Effect for the Cytochrome P-450 Catalyzed Hydroxylation of n-Octane into Its Primary and Secondary Components
-
The intramolecular isotope effect for the cytochrome P-450b ω-hydroxylation of -n-octane was separated into its primary and secondary components by the method of Hanzlik (Hanzlik et al.J.Am.Chem.Soc. 1985, 107, 7164).The primary isotope effect was found to lie between 7.3 and 7.9 while the secondary isotope effect was found to lie between 1.09 and 1.14.These data are consistent with a highly symmetrical transition state with 15percent of the observed isotope effect being due to secondary isotope effects.Although the system was found to depart from the rule of the geometric mean, the phenomenon could not be attributed to tunneling.
- Jones, Jeffrey P.,Trager, William F.
-
-
Read Online
- Absolute stereochemistry of petroformynes, high molecular polyacetylenes from the marine sponge Petrosia ficiformis
-
The absolute stereochemistry of some petroformynes (1-7), characteristic metabolites of the Mediterranean sponge Petrosia ficiformis displaying terminal 1-yn-3-ol-4-ene moieties, has been elucidated by applying high field 1H-NMR to Mosher method. Esterification of Petrosia polyacetylenes with (R)- and (S)-α-methoxy-α-trifluoromethylphenylacetyl (MTPA) chloride yielded the corresponding (S)- and (R)-MTPA esters. Careful NMR measurements led to assign the S absolute stereochemistry at all the chiral centers of petroformynes. The R absolute stereochemistry of 3-hydroxydocosa-4(E) 15(E)-dien-1-yne (8), previously established on the basis of a questionable extention of the application of the exciton chirality method, is confirmed by applying advanced Mosher method. The structures of petroformyne-5 (7) and petroformyne-8 (11) are now supported by additional evidence.
- Guo, Yuewei,Gavagnin, Margherita,Trivellone, Enrico,Cimino, Guido
-
-
Read Online
- An epigenetic modifier enhances the production of anti-diabetic and anti-inflammatory sesquiterpenoids from Aspergillus sydowii
-
The addition of a DNA methyltransferase inhibitor, 5-azacytidine, to Aspergillus sydowii fungus culture broth changed its secondary metabolites profile. Analysis of the culture broth extract led to the isolation of three new bisabolane-type sesquiterpenoids: (7S)-(+)-7-O-methylsydonol (1), (7S,11S)-(+)-12-hydroxysydonic acid (2) and 7-deoxy-7,14-didehydrosydonol (3), along with eight known compounds. The isolated compounds were evaluated for their anti-diabetic and anti-inflammatory activities. Among the isolates, (S)-(+)-sydonol (4) did not only potentiate insulin-stimulated glucose consumption but also prevented lipid accumulation in 3T3-L1 adipocytes. Additionally, (S)-(+)-sydonol (4) exhibited significant anti-inflammatory activity through inhibiting superoxide anion generation and elastase release by fMLP/CB-induced human neutrophils. This is the first report on isolating a secondary metabolite with anti-diabetic and anti-inflammatory activities from microorganisms.
- Chung, Yu-Ming,Wei, Chien-Kei,Chuang, Da-Wei,El-Shazly, Mohamed,Hsieh, Chi-Ting,Asai, Teigo,Oshima, Yoshiteru,Hsieh, Tusty-Jiuan,Hwang, Tsong-Long,Wu, Yang-Chang,Chang, Fang-Rong
-
-
Read Online
- TARGET PROTEIN EED DEGRADATION-INDUCING DEGRADUCER, PREPARATION METHOD THEREOF, AND PHARMACEUTICAL COMPOSITION FOR PREVENTING OR TREATING DISEASES RELATED TO EED, EZH2, OR PRC2, COMPRISING SAME AS ACTIVE INGREDIENT
-
The present invention relates to a target protein degradation-inducing Degraducer, a preparation method thereof, and a pharmaceutical composition for preventing or treating diseases related to EED, EZH2, or PRC2 comprising same as an active ingredient. A novel compound represented by formula 1, according to the present invention is a Degraducer compound that induces degradation of a target protein, i.e., embryonic ectoderm development (EED) or polycomb repressive complex 2 (PRC2), utilizing cereblon E3 ubiquitin ligase, von Hippel-Lindau tumor suppressor (VHL) E3 ubiquitin ligase, mouse double minute 2 homolog (MDM2) E3 ubiquitin ligase, and cellular inhibitor of apoptosis protein 1 (cIAP) E3 ubiquitin ligase, wherein the compound has an aspect of remarkably achieving target protein degradation-inducing activity through a ubiquitin proteasome system (UPS), and therefore there is a useful effect in that it is possible to provide a pharmaceutical composition for preventing or treating diseases or conditions related to a target protein, and a functional health food composition for preventing or improving same, comprising said compound as an active ingredient.
- -
-
-
- Efficient Palladium-Catalyzed Carbonylation of 1,3-Dienes: Selective Synthesis of Adipates and Other Aliphatic Diesters
-
The dicarbonylation of 1,3-butadiene to adipic acid derivatives offers the potential for a more cost-efficient and environmentally benign industrial process. However, the complex reaction network of regioisomeric carbonylation and isomerization pathways, make a selective and direct transformation particularly difficult. Here, we report surprising solvent effects on this palladium-catalysed process in the presence of 1,2-bis-di-tert-butylphosphin-oxylene (dtbpx) ligands, which allow adipate diester formation from 1,3-butadiene, carbon monoxide, and methanol with 97 % selectivity and 100 % atom-economy under scalable conditions. Under optimal conditions a variety of di- and triesters from 1,2- and 1,3-dienes can be obtained in good to excellent yields.
- Yang, Ji,Liu, Jiawang,Ge, Yao,Huang, Weiheng,Ferretti, Francesco,Neumann, Helfried,Jiao, Haijun,Franke, Robert,Jackstell, Ralf,Beller, Matthias
-
supporting information
p. 9527 - 9533
(2021/03/08)
-
- Ultralow-Molecular-Weight Stimuli-Responsive and Multifunctional Supramolecular Gels Based on Monomers and Trimers of Hydrazides
-
The simpler, the better. A series of simple, neutral and ultralow-molecular-weight (MW: 140–200) hydrazide-derived supramolecular gelators have been designed and synthesized in two straightforward steps. For non-conjugated cyclohexane-derived hydrazides, their monomers can self-assemble to form gels through intermolecular hydrogen bonds and dipole-dipole interactions. Significantly, conjugated phthalhydrazide can self-aggregate into planar and circular trimers through intermolecular hydrogen bonds and then self-assemble to form gels through intermolecular π–π stacking interactions. It is interesting that these simple gelators exhibit unusual properties, such as self-healing, multi-response fluorescence, and visual and selective recognition of chiral (R)/(S)-1,1′-binaphthalene-2,2′-diamine and S2? through much different times of gel re-formation and blue-green color change, respectively. These results underline the importance of supramolecular gels and extend the scope of supramolecular gelators.
- Wu, Dehua,Song, Jintong,Qu, Lang,Zhou, Weilan,Wang, Lei,Zhou, Xiangge,Xiang, Haifeng
-
supporting information
p. 3370 - 3378
(2020/10/02)
-
- One and Two-Carbon Homologation of Primary and Secondary Alcohols to Corresponding Carboxylic Esters Using β-Carbonyl BT Sulfones as a Common Intermediate
-
Herein we report the efficient one- and two-carbon homologation of 1° and 2° alcohols to their corresponding homologated esters via the Mitsunobu reaction using β-carbonyl benzothiazole (BT) sulfone intermediates. The one-carbon homologation approach uses standard Mitsunobu C-S bond formation, oxidation and subsequent alkylation, while the two-carbon homologation uses a less common C-C bond forming Mitsunobu reaction. In this latter case, the use of β-BT sulfone bearing esters lowers the pKa sufficiently enough for the substrate to be used as a carbon-based nucleophile and deliver the homologated β-BT sulfone ester, and this superfluous sulfone group can then be cleaved. In this paper we describe several methods for the effective desulfonylation of BT sulfones and have developed methodology for one-pot alkylation-desulfonylation sequences. As such, overall, a one-carbon homologation sequence can be achieved in a two-pot (four step) procedure and the two-carbon homologation in a two-pot (three step) procedure (three-pot; four step when C-acid synthesis is included). This methodology has been applied to a wide variety of functionality (esters, silyl ethers, benzyls, heteroaryls, ketones, olefins and alkynes) and are all tolerated well providing good to very good overall yields. The power of our method was demonstrated in site-selective ingenol C20 allylic alcohol two-carbon homologation.
- Bon, David J.-Y. D.,Ková?, Ond?ej,Ferugová, Vendula,Zále?ák, Franti?ek,Pospí?il, Ji?í
-
p. 4990 - 5001
(2018/05/17)
-
- Methylation of mono- and dicarboxylic acids with dimethyl carbonate catalyzed with binder-free zeolite NaY
-
Synthesis of methyl mono- and dicarboxylates was developed consisting in treating the corresponding acids with dimethyl carbonate in the presence of a heterogenic catalyst, crystalline aluminosilicate whose mechanically strong granules to 90–95% were built of crystal aggregates of zeolite Y with modulus of about 5.0 in the Na-form. Optimum catalyst and reagents ratio and the reaction conditions were found for the preparation in high yields of methyl esters of mono- and dicarboxylic acids.
- Khusnutdinov,Shchadneva,Mayakova, Yu. Yu.,Konovalova, Yu. S.,Khazipova,Kutepov
-
p. 163 - 168
(2017/04/24)
-
- Photoredox-Assisted Reductive Cross-Coupling: Mechanistic Insight into Catalytic Aryl-Alkyl Cross-Couplings
-
Here, we describe a photoredox-assisted catalytic system for the direct reductive coupling of two carbon electrophiles. Recent advances have shown that nickel catalysts are active toward the coupling of sp3-carbon electrophiles and that well-controlled, light-driven coupling systems are possible. Our system, composed of a nickel catalyst, an iridium photosensitizer, and an amine electron donor, is capable of coupling halocarbons with high yields. Spectroscopic studies support a mechanism where under visible light irradiation the Ir photosensitizer in conjunction with triethanolamine are capable of reducing a nickel catalyst and activating the catalyst toward cross-coupling of carbon electrophiles. The synthetic methodology developed here operates at low 1 mol % catalyst and photosensitizer loadings. The catalytic system also operates without reaction additives such as inorganic salts or bases. A general and effective sp2-sp3 cross-coupling scheme has been achieved that exhibits tolerance to a wide array of functional groups.
- Paul, Avishek,Smith, Mark D.,Vannucci, Aaron K.
-
p. 1996 - 2003
(2017/02/26)
-
- The synthesis of di-carboxylate esters using continuous flow vortex fluidics
-
A vortex fluidic device (VFD) is effective in mediating the synthesis of di-esters at room temperature. Processing under ambient conditions allows for a simple and efficient synthesis, whilst operating under continuous flow addresses scalability. The rotational speed of the sample tube and the flow rate were critical variables during reaction optimization, and this relates to the behaviour of the fluid flow at a molecular level. Whilst at specific rotational speeds the tube imparts a vibrational response into the fluid flow, the flow rate dictates residence time and the ability to maintain high levels of shear stress. The combination of mechanically induced vibrations, rapid micromixing, high levels of shear stress and water evaporation results in yields up to 90% for 3.25 minutes or less residence time. These results are key for devising greener and more efficient processes both mediated by the VFD and other continuous flow platforms.
- Britton, Joshua,Dalziel, Stuart B.,Raston, Colin L.
-
p. 2193 - 2200
(2016/04/19)
-
- Selective monomethyl esterification of linear dicarboxylic acids with bifunctional alumina catalysts
-
An environmentally friendly protocol for the selective protection of dicarboxylic acids is reported using methanol as a cheap esterifying agent and alumina as a heterogeneous catalyst; the selectivity of the process has been ascribed to a balanced acidity/basicity of the bifunctional alumina catalyst.
- Santacroce, Veronica,Bigi, Franca,Casnati, Alessandra,Maggi, Raimondo,Storaro, Loretta,Moretti, Elisa,Vaccaro, Luigi,Maestri, Giovanni
-
supporting information
p. 5764 - 5768
(2016/11/06)
-
- Discovery, bioactivity and docking simulation of Vorinostat analogues containing 1,2,4-oxadiazole moiety as potent histone deacetylase inhibitors and antitumor agents
-
Abstract In our study, three series of hydroxamate, 2-aminobenzamide, and trifluoromethyl ketone analogues have been designed and synthesized. The synthesized compounds were investigated for their in vitro antiproliferative activities using the MTT-based assay against three human cancer cell lines including A549, NCI-H661, and U937. Most analogues exhibited higher antiproliferative activities against human acute myeloid leukemia cell U937 than the other two human lung cancer cell lines. Furthermore, the compounds were examined against HDAC1, 2, and 8 isoforms. Docking study of compounds 6h, 9b, and 10a suggested that they might bind tightly to the binding pocket of HDAC2 and/or HDAC8. The results suggest that these compounds might have potential as lead compounds for the development of anti-tumor drugs with HDACs inhibitory activities.
- Cai, Jin,Wei, Hongtao,Hong, Kwon Ho,Wu, Xiaoqing,Zong, Xi,Cao, Meng,Wang, Peng,Li, Lushen,Sun, Chunlong,Chen, Bo,Zhou, Gaoxing,Chen, Junqing,Ji, Min
-
p. 3457 - 3471
(2015/08/03)
-
- Lewis Base Activation of Silyl Acetals: Iridium-Catalyzed Reductive Horner-Wadsworth-Emmons Olefination
-
A Lewis base promoted deprotonative pronucleophile addition to silyl acetals has been developed and applied to the iridium-catalyzed reductive Horner-Wadsworth-Emmons (HWE) olefination of esters and the chemoselective reduction of the resulting enoates. Lewis base activation of silyl acetals generates putative pentacoordinate silicate acetals, which fragment into aldehydes, silanes, and alkoxides in situ. Subsequent deprotonative metalation of phosphonate esters followed by HWE with aldehydes furnishes enoates. This operationally convenient, mechanistically unique protocol converts the traditionally challenging aryl, alkenyl, and alkynyl esters to homologated enoates at room temperature within a single vessel.
- Dakarapu, Udaya Sree,Bokka, Apparao,Asgari, Parham,Trog, Gabriela,Hua, Yuanda,Nguyen, Hiep H.,Rahman, Nawal,Jeon, Junha
-
supporting information
p. 5792 - 5795
(2015/12/11)
-
- PROCESS FOR PREPARING A CARBOXYLIC ACID FROM A DIOL OR FROM AN EPOXIDE BY OXIDATIVE CLEAVAGE
-
A process for preparing a carboxylic acid, by oxidative cleavage of at least one vicinal diol, or an epoxide, wherein the reaction is carried out in the presence of a catalyst and of an oxidizing agent and in the absence of solvent.
- -
-
Paragraph 0106; 0107; 0108; 0109; 0110; 0111; 0112
(2015/08/04)
-
- METHOD OF MANUFACTURE OF OCTANEDIOIC ACID, PRECURSORS, AND DERIVATIVES
-
A method for the manufacture of 1,8-octanedioic acid comprises: reacting gamma-valerolactone with an alcohol in the presence of an acid or a base catalyst to provide an alkyl pentenoate, converting the alkyl pentenoate in the presence of a metathesis initiator to provide the dialkyl octenedioate, reacting the dialkyl octenedioate with hydrogen in the presence of a hydrogenation catalyst to provide a dialkyl 1,8-octanedioate and hydrolyzing the dialkyl 1,8-octanedioate to provide the 1,8-octanedioic acid.
- -
-
Paragraph 0086; 0087; 0088
(2014/10/04)
-
- Metal/bromide autoxidation of triglycerides for the preparation of FAMES to improve the cold-flow characteristics of biodiesel
-
Triglyceride autoxidation using a homogeneous Co/Mn/Zr/bromide catalyst in acetic acid (93%) of low grade tallow, canola oil or soy bean oil in a batch reactor at 150 °C for 2 h, produced lower molecular weight products relative to the fatty acids of the starting triglycerides. For the autoxidation of tallow the main products after esterification were monoesters Me(CH 2)mC(O)OMe (m = 5-12) and diesters MeOC(O)(CH 2)nC(O)OMe, (n = 7-12). Oxidation of the saturated fatty acids in triglycerides was confirmed and modelled using methyl palmitate. Post-treatment esterification of tallow autoxidation products to produce biodiesel (BD) esters resulted in improved cold temperature properties by a mean of 13.0 °C, i.e. a mean cloud point (CP) 1.0 °C (cf. unmodified tallow biodiesel: CP 14 °C).
- Phung, Peter,Rowlands, William N.,Thiyakesan, Appadurai,Benndorf, Paul,Masters, Anthony F.,Maschmeyer, Thomas
-
p. 162 - 168
(2014/07/07)
-
- Transformations of peroxide olefin ozonolysis products in methanol in the presence of water
-
Transformations of peroxide products of ozonolysis of various olefins with different degrees of substitution at the double bond by the action of hydroxylamine and semicarbazide hydrochloride in methanol in the presence of water as co-solvent were studied.
- Ishmuratov,Legostaeva,Garifullina,Botsman,Muslukhov,Tolstikov
-
p. 1415 - 1419
(2014/01/06)
-
- Tetrapropylammonium perruthenate catalyzed glycol cleavage to carboxylic (Di)acids
-
A new method to accomplish glycol cleavage to carboxylic (di)acids in one step using catalytic amounts of tetrapropylammonium perruthenate (TPAP) together with N-methylmorpholine N-Oxide (NMO) as the stoichiometric oxidant is presented. In addition to regenerating the active catalyst, the N-oxide stabilizes intermediary carbonyl hydrates and thereby shifts a crucial equilibrium. The mild oxidation protocol is applicable to a broad range of substrates providing the respective acids, diacids, or keto acids in high yields.
- Schmidt, Andrea-Katharina C.,Stark, Christian B. W.
-
p. 5788 - 5791
(2011/12/05)
-
- Iridium-catalyzed oxidative methyl esterification of primary alcohols and diols with methanol
-
Oxidative methyl esterification of primary alcohols and diols with methanol was successfully achieved, using acetone as a hydrogen acceptor, under the influence of an iridium complex combined with 2-(methylamino)ethanol (MAE) as catalyst.
- Yamamoto, Nobuyuki,Obora, Yasushi,Ishii, Yasutaka
-
experimental part
p. 2937 - 2941
(2011/05/30)
-
- Ozonolysis of alkenes and study of reactions of polyfunctional compounds: LXVIII. Investigation of transformations of peroxide products of olefins ozonolysis treated with hydroxylamine hydrochloride
-
Hydroxylamine hydrochloride efficiently reduces peroxide products of olefins ozonolysis into carbonyl compounds. Depending on the substrate character, solvent, and the treatment conditions the arising aldehydes transformed along the route aldehyde→aldoxime→nitrile→ester into individual compounds or their mixtures, or give the corresponding acetals.
- Ishmuratov,Shayakhmetova,Yakovleva,Legostaeva,Shitikova,Galkin,Tolstikov
-
p. 1114 - 1119
(2008/03/11)
-
- Synthesis of long-chain 3-alkylpyrroles bearing terminal carboxy or amino groups
-
Two new ω-(1H-pyrrol-3-yl)alkanoic acids 8a,b and the corresponding amines 9a,b were prepared on large scale in 41-51 and 27-39% overall yield, respectively, starting from N-phenylsulfonyl-protected pyrrole. The target compounds contain the desired functional groups for attachment of biomolecules such as proteins. During synthesis, an unprecedented partial reduction of the pyrrole ring with NaBH3CN in glacial AcOH was observed, for which a plausible mechanism is proposed (Scheme 3).
- Freitas, Jose M.,Abrantes, Luisa M.,Darbre, Tamis
-
p. 2470 - 2478
(2007/10/03)
-
- Ruthenium catalysed oxidation without CCl4 of oleic acid, other monoenic fatty acids and alkenes
-
Ruthenium catalysed oxidation of alkenes and monoenic fatty acids is reported. The study of the influence of cosolvents (H2O/MeCN/X) shows that toxic CCl4 initially used in the Sharpless system (H 2O/MeCN/CCl4) can be avoided and demonstrates that the oxidative cleavage of CC bond could be accomplished in good yields with H 2O/MeCN/AcOEt solvent system in a ratio 3/2/2, respectively.
- Zimmermann, Fran?ois,Meux, Eric,Mieloszynski, Jean-Luc,Lecuire, Jean-Marie,Oget, Nicolas
-
p. 3201 - 3203
(2007/10/03)
-
- Direct oxidative cleavage of α- and β-dicarbonyls and α-hydroxyketones to diesters with KHSO5
-
Presented is a methodology to oxidatively cleave α-hydroxyketones and α- or β-diones using the environmentally benign reagent KHSO 5, prepared easily from Oxone, to diesters in one simple transformation. In addition, we undertook a mechanistic study to provide a plausible mechanistic interpretation. These reactions may prove to be valuable alternatives to other related metal-mediated processes.
- Yan, Jun,Travis, Benjamin R.,Borhan, Babak
-
p. 9299 - 9302
(2007/10/03)
-
- Highly efficient esterification of carboxylic acids with alcohols by montmorillonite enwrapped titanium as a heterogeneous acid catalyst
-
Montmorillonite-enwrapped titanium catalyst was found to efficiently promote the esterification of carboxylic acids with alcohols. In comparison to other catalysts reported to date, this heterogeneous catalyst offers a remarkably simple workup procedure, and is reusable without any appreciable loss in its activity and selectivity.
- Kawabata, Tomonori,Mizugaki, Tomoo,Ebitani, Kohki,Kaneda, Kiyotomi
-
p. 9205 - 9208
(2007/10/03)
-
- Catalytic osmium-assisted oxidative cleavage of olefins
-
An osmium-assisted process for the oxidative cleavage of oxidizable organic compounds such as unsaturated organic compounds, including alkenes and olefins into aldehydes, carboxylic acids, esters, or ketones. The process uses a metal catalyst comprising osmium and a peroxy compound selected from the group consisting of peroxymonosulfuric acid and salts thereof to oxidatively cleave the oxidizable organic compound. In particular, the process enables aldehydes, carboxylic acids, esters, or ketones to be selectively produced from the corresponding mono-, 1,1-di-, 1,2-di-, tri-, or tetra-substituted olefins in a reaction that produces the result of ozonolysis but with fewer problems. The present invention further provides a process for oxidizing an aldehyde alone or with the osmium in an interactive solvent to produce an ester or carboxylic acid.
- -
-
-
- Palladium(II)-catalyzed oxidation of aldehydes and ketones. 1. Carbonylation of ketones with carbon monoxide catalyzed by palladium(II) chloride in methanol
-
Unsubstituted or alkyl-substituted cyclic ketones react with PdCl2 in methanol under a CO atmosphere to give mainly acyclic diesters along with some acyclic chloro-substituted monoesters. The monosubstituted cyclic ketones, 2-hydroxy- and 2-methoxycyclohexanone, do not give ring cleavage but rather produce 2-(carbomethoxy)cyclohex-2-en-1-one. 13CO labeling experiments indicate one CO is inserted in forming the diester product so the second ester group must arise from the original ketone group. Two mechanisms are possible for the diester reaction. One involves initial Pd(II)-CO2CH3 insertion across the double bond of the enol form of the ketone while the second involves initial addition of Pd(II)-OCH3 followed by CO insertion into the new Pd(II) carbon bond formed. Pd(II) elimination and acid-catalyzed ring cleavage produce the second methyl ester group in both routes. The chloro-substituted monoester is formed by initial Pd(II)-Cl insertion across the double bond followed by the acid-catalyzed ring cleavage. The 2-(carbomethoxy)cyclohex-2-en-1-one must result from elimination of water or methanol from the α-ketoester product formed by the initial methoxycarbonylation of the enol form of the ketone. As expected, the acyclic ketone 2-decanone, formed methyl acetate and a mixture of methyl nonanoate and products.
- Hamed,El-Qisairi,Henry
-
p. 180 - 185
(2007/10/03)
-
- Palladium(II) catalyzed carbonylation of ketones
-
Cyclic ketones react with PdCl2 in methanol under a CO atmosphere to give mainly diesters by a ring cleavage reaction along with some chloro- substituted monoester, 13CO labeling experiments indicate the major product is formed by a mechanism involving Pd(II)-CO2CH3 insertion across the double bond of the enol form of the ketone. Pd(II) elimination and acid- catalyzed ring cleavage form a second methyl ester group. (C) 2000 Elsevier Science Ltd.
- Hamed, Othman,El-Qisairi, Arab,Henry, Patrick M.
-
p. 3021 - 3024
(2007/10/03)
-
- Oxidation of 2-substituted cycloalkanones with cerium(IV) sulfate tetrahydrate in alcohols and acetic acid
-
The reaction of 2-substituted cycloalkanones with cerium(IV) sulfate tetrahydrate (CS) in alcohols and acetic acid gave the corresponding alkyl esters of oxo acids (80-96%) and oxo acids (78-96%), respectively, by oxidative cleavage of the C(R).C=O bond. In the case of 2-iodocycloalkanones in methanol, the dimethyl ester was obtained in good yield. A treatment of 5α-cholestan-3-one with CS in methanol produced 2-acetal 3-ester of 2,3-seco derivative in good yield. The effects of cerium(IV) and copper(II) salts are also discussed.
- He, Liangyou,Horiuchi, C. Akira
-
p. 2515 - 2521
(2007/10/03)
-
- An efficient asymmetric synthesis of prostaglandin E1
-
An asymmetric total synthesis of Prostaglandin E1 (5) has been achieved in a two-component coupling process. The chiral hydroxycyclopentenone 6 was readily available from furan with 96% ee. The key reaction step was a kinetic enzymatic resolution followed by an in situ inversion. A catalytic asymmetric reduction of the γ-iodo vinyl ketone 19 with the Corey CBS catalyst gave the ω-side chain 7 with >96% ee. Conjugate addition using the reaction with dilithiocyanocuprate followed by mild cleavage of the silyl protective groups and enzymatic hydrolysis of the methyl ester 22 gave (-)-PGE1 5 in high yield.
- Rodriguez, Ana,Nomen, Miguel,Spur, Bernd Werner,Godfroid, Jean-Jacques
-
p. 2655 - 2662
(2007/10/03)
-
- A selective method for the preparation of aliphatic methyl esters in the presence of aromatic carboxylic acids
-
2,2-Dimethoxypropane, methanol and a catalytic amount of HCl selectively esterify aliphatic carboxylic acids, in the presence of aromatic carboxylic acids, at room temperature and in high yields.
- Rodriguez,Nomen,Spur,Godfroid
-
p. 8563 - 8566
(2007/10/03)
-
- α-nitrocycloalkanones as a source of α,ω,-dicarboxylic acid dimethyl esters
-
α,ω-Dicarboxylic acid dimethyl esters arc easily obtained by ring cleavage of α-nitrocycloalkanones. Thus, reaction of the latter compounds with three equivalents of potassium persulfate, in methanol and in presence of sulfuric acid at 80 °C, provides α,ω-dicarboxylic acid dimethyl esters in high yields. Long-chain, and alkylated α,ω-dicarboxylic acid dimethyl esters can be also efficiently obtained.
- Ballini, Roberto,Bosica, Giovanna
-
p. 16131 - 16138
(2007/10/03)
-
- Oxidative Cleavage of Mono-, Di-, and Trisubstituted Olefins to Methyl Esters through Ozonolysis in Methanolic NaOH
-
The ozonolysis of alkenes in methanolic NaOH or NaOMe with CH2Cl2 as cosolvent leads directly to methyl esters.The procedure has been used to prepare various α-, β-, and ω-alkoxy esters, acyloxy esters, and α- and β-N-acyl and N-sulfonyl esters from appropriate unsaturated ethers, esters and amides.Other examples include the formation of dimethyl octanedioate from cyclooctene (75percent yield), dimethyl nonanedioate and methyl nonaoate from methyl oleate (77 and 78percent, respectively), and tetradecanoic acid γ-lactone from 2-methyl-2-hexadecen-6-ol (80percent yield).
- Marshall, James A.,Garofalo, Albert W.
-
p. 3675 - 3680
(2007/10/02)
-
- Selective Kolbe Electrolytic Coupling Using Glasslike-Hard Carbon Anodes
-
The use of some kinds of glasslike-hard carbons was found to lead to selective synthesis of the corresponding Kolbe coupled products in high yields comparable to the use of a Pt anode in anodic oxidation of some carboxylic acids.
- Ohno, Toshinobu,Fukumoto, Tatsumi,Hirashima, Tsuneaki,Nishiguchi, Ikuzo
-
p. 1085 - 1088
(2007/10/02)
-
- Ozonolysis of Olefins, V : Emulsion Ozonization of Methyl Linoleate and Methyl Linolenate in Aqueous Alkaline Hydrogen Peroxide
-
The ozonolysis of methyl linoleate and methyl linolenate in neutral and alkaline aqueous emulsions of hydrogen peroxide was investigated.Besides the expected products such as dimethyl malonate (3b), dimethyl azelate (3h) and methyl hexanoate (2a) further homologous methyl esters of dicarboxylic acids (3a-g), oxo carboxylic acids (4a, b, e-h) and hydroxy carboxylic acids (4c, d) could be detected by GC/MS analysis.Furthermore a method for separation of 8-hydroxyoctanoic acid (4d) by methylation and extraction of the reaction mixture containing the ozonolysis products is described. Keywords.Ozonization; Fatty esters; 8-Hydroxyoctanoic acid.
- Poklukar, Norbert,Mittelbach, Martin
-
p. 719 - 724
(2007/10/02)
-
- Syntheses d'amidoesters par reaction de Kolbe
-
The synthesis of amidoesters has been investigated by anodic cooxidation of diacid hemiesters CO2H-CH2-Z-CO2CH3 -CH2-> and amidoacids R1-N(Y)-(CH2)2-CO2H .The scope of this reaction was examined in detail.This synthetic pathway provided very a simple access to a wide range of amidoesters R1-N(Y)-(CH2)3-Z-CO2CH3 by varying Z and R1 as well as n value.
- Abderrahman, Ben Moufida,Laurent, Eliane,Marquet, Bernard
-
p. 571 - 578
(2007/10/02)
-
- Optimisation of Product(s) Yield in Cross-Kolbe Electrolysis
-
The influence of changes in the molar concentrations of the reacting acids on cross-product formation in Kolbe electrolysis has been studied using a mixture of levulinic acid and monomethyl glutarate.
- Dandge, Chitra N.,Naik, D. G.,Kapadi, A. H.
-
p. 854 - 855
(2007/10/02)
-
- Bifunctional compounds from reaction of alkoxy hydroperoxides with metal salts
-
Alkoxy hydroperoxides, obtained by ozonizing olefins in alcoholic solution, were treated with ferrous sulfate. C-C bond scission and radical formation was followed by dimerization of the radicals formed. Ozonides reacted similarly. Acyclic and cyclic olefins, including a cyclic enol ether, gave rise to a range of α,ω-disubstituted products in modest yields. By using ferric chloride, ω-chloro esters were obtained from the alkoxy hydroperoxides derived from olefinic esters.
- Cardinale,Laan,Van Der Steen,Ward
-
p. 6051 - 6054
(2007/10/02)
-
- AN 8-HYDROXYOCTADECA-CIS-11,14-DIENOIC ACID FROM MIRABILIS JALAPA SEED OIL
-
A fatty acid, found as a minor component in the seed oil of Mirabilis jalapa, is shown to be the hitherto unknown 8-hydroxyoctadeca-cis-11,14-dienoic acid. - Key Word Index: Mirabilis jalapa; Nyctaginaceae; seed oil; 8-hydroxyoctadeca-cis-11,14-dienoic acid.
- Ahmad, Mohammad Shamim,Rauf, Abdul,Mustafa, Jamal,Osman, Sheikh Mohammad
-
p. 2247 - 2250
(2007/10/02)
-
- The Synthesis of Specifically and Selectively Deuteriated 4,4'-Bisalkoxyazoxybenzene Derivatives
-
In connection with deuterium n.m.r. studies of molecular motion in liquid crystals we have developed a number of methods for the synthesis of selectively deuteriated 4,4'-bisalkoxyazoxybenzenes.This paper is concerned with (i) the labelling of specific methylene segments of the alkoxy-chains, (ii) the labelling of the aromatic nucleus, and (iii) the selective enrichment of the deuterium content of one alkoxy-chain relative to the other.Our studies of the n.m.r. spectra of these liquid crystals have shown that there is not (as has sometimes been supposed) a monotonic decrease in C-D quadrupole splitting in passing from the oxygen to the CD3 end of the alkoxy-chain.In -PAA (p-azoxyanisole) we have also shown that the smaller splitting is associated with the CD3O group nearest to the NO end of azoxy-group.Whereas the photorearrangement of azoxy-compounds is normally regiospecific, the photorearrangement of PAA selectively deuteriated in one methoxy-group is unusual in that it leads to isotopically scrambled products.
- Boden, Neville,Bushby, Richard J.,Clark, Leslie D.
-
p. 543 - 551
(2007/10/02)
-
- Kolbe Synthesis of Unsaturated Pheromones by Coelectrolysis with 5-Alkynoic Acids
-
The alkynoic acids 5a - g are synthesized by coelectrolysis of 5-alkynoic acids 2a - c with dicarboxylic monoesters 3a - d.By reduction, Lindlar-hydrogenation, and acetylation these are converted into pheromones such as (Z)-11-hexadecenyl acetate (7b), the pheromone of Mamestra brassicae. 2a - c can be prepared by alkynylation of 1-bromo-3-chloropropane to 1a - c, substitution by cyanide and hydrolysis.
- Seidel, Wolfgang,Schaefer, Hans J.
-
p. 3898 - 3903
(2007/10/02)
-
- Useful Intermediates for Synthesis of Dicarba Analogues of Cystine Peptides: Selectively Protected α-Aminosuberic Acid and α,α'-Diaminosuberic Acid of Defined Stereochemistry
-
Practical procedures are described for synthesis of selectively protected α-aminosuberic acid and α,α'-diaminosuberic acid by the mixed Kolbe electrolytic decarboxylative dimerization of two different carboxylic acids.Stereochemistry is established by the choice of L- or D-glutamic acid precursors.The method is illustrated by the synthesis of α-tert-butyl Nα-Boc-Nα'-Cbz-LL-α,α'-diaminosuberate (6) and α-tert-butyl ω-methyl Nα-Boc-D-α-aminosuberate (10) which can be used directly in the preparation of dicarba and desaminodicarba analogues of cystinepeptides.Although statistically controlled mixtures are produced, facile procedures for isolation of the products have been worked out.No racemization of chiral centers was detected.
- Nutt, Ruth F.,Strachan, Robert G.,Veber, Daniel F.,Holly, Frederick W.
-
p. 3078 - 3080
(2007/10/02)
-
- OZONOLYSIS OF ALKENES AND REACTIONS OF POLYFUNCTIONAL COMPOUNDS. XVIII. INVESTIGATION OF A NEW OZONOLYTIC SYNTHESIS OF CARBOXYLIC ACIDS
-
By identification of the 18O isotope label in the oligomeric peroxide obtained by ozonization of a cyclic olefin in the presence of heavy oxygen and also in the product from catalytic isomerization of this peroxide ( the α,ο-dicarboxylic acids or its dimethyl ester ) it was shown that oxygen enters the ozonolysis product when the reaction is carried out in ether solvents.It is suggested that the increased content of active oxygen in the ozonolysis peroxy product is due to oxidation of the ether solvent to form α-hydroperoxide and addition of the latter to the oligomeric zwitterion, solvated by the polar solvents.It was established that the catalytic and thermal isomerization of the oligomeric peroxides and ozonides of cyclic olefins to the α,ο-dicarboxylic acids and ο-formyl carboxylic acids occurs through the oligomeric α-hydroxy peresters and α-hydroxy esters respectively.
- Odinokov, V. N.,Botsman, L. P.,Ishmuratov, G. Yu.,Tolstikov, G. A.
-
p. 453 - 463
(2007/10/02)
-