- Sustainable electroorganic synthesis of lignin-derived dicarboxylic acids
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The oxidative ring opening of lignin-derived alkylated cyclohexanols to bio-based alkylated dicarboxylic acids is successfully performed by an electrocatalytic conversion. To establish this transformation as a green method, we developed a simple protocol for the anodic oxidation at nickel oxide-hydroxide (NiOOH) foam anodes in caustic soda in both a batch and flow electrolysis approach.
- Rauen, Anna Lisa,Waldvogel, Siegfried R.,Weinelt, Frank
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supporting information
p. 5956 - 5960
(2020/10/18)
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- Method for synthesizing muscone by utilizing beta-monomethyl methylglutarate
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The invention discloses a method for synthesizing muscone by utilizing beta-monomethyl methylglutarate. According to the method, beta-monomethyl methylglutarate and alpha,omega-dodecanedioic acid monomethyl ester respectively prepared through a heteropoly acid catalytic transesterification method are used as raw materials, and Kolbe electrolysis, acyloin condensation and reduction reaction are performed to prepare the muscone. The method of the present invention has advantages of high raw material utilization rate, mold condition, easy control and environmental protection, and is suitable for industrial production .
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Paragraph 0021; 0022
(2017/12/05)
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- A new method for the preparation of non-terminal alkynes: Application to the total syntheses of tulearin A and C
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Lactones are known to react with the reagent generated in situ from CCl4 and PPh3 in a Wittig-type fashion to give gem-dichloro-olefin derivatives. Such compounds are now shown to undergo reductive alkylation on treatment with organolithium reagents RLi to furnish acetylene derivatives bearing the substituent R at their termini (R=Me, n-, sec-, tert-alkyl, silyl); the reaction can be catalyzed with either Cu(acac)2 or Fe(acac)3/1,2-diaminobenzene. Two alkynol derivatives prepared in this way from readily accessible lactone precursors served as the key building blocks for the total syntheses of the cytotoxic marine macrolides tulearin A (1) and C (2). The assembly of these fragile targets hinged upon ring closing alkyne metathesis (RCAM) followed by a formal trans-reduction of the resulting cycloalkynes via trans-hydrosilylation/protodesilylation.
- Lehr, Konrad,Schulthoff, Saskia,Ueda, Yoshihiro,Mariz, Ronaldo,Leseurre, Lucie,Gabor, Barbara,Fürstner, Alois
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supporting information
p. 219 - 227
(2015/02/19)
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- Two potent OXE-R antagonists: Assignment of stereochemistry
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5-Oxo-6,8,11,14-eicosatetraenoic acid (5-oxo-ETE) is formed by the oxidation of 5-hydroxy-6E,8Z,11Z,14Z-eicosatetraenoic acid (5-HETE), which is a major metabolite of enzymatic oxidation of arachidonic acid (AA). 5-Oxo-ETE is the most potent lipid chemoattractant for human eosinophils. Its actions are mediated by the selective OXE receptor, which is therefore an attractive target in eosinophilic diseases such as allergic rhinitis and asthma. Recently, we have reported two excellent OXE receptor antagonists that have IC50 values at low nanomolar concentrations. Each of these antagonists has a chiral center, and the isolation of the individual enantiomers by chiral high-performance liquid chromatography (HPLC) revealed that in each case one enantiomer is over 300 times more potent than the other. To unambiguously assign the stereochemistry of these enantiomers and to provide access to larger amounts of the active compounds for biological testing, we report here their total synthesis.
- Patel, Pranav,Reddy, Chintam Nagendra,Gore, Vivek,Chourey, Shishir,Ye, Qiuji,Ouedraogo, Yannick P.,Gravel, Sylvie,Powell, William S.,Rokach, Joshua
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p. 815 - 819
(2014/08/05)
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- Total synthesis of tulearin C
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With the help of the smaller brother: Although alkyne metathesis will always be the little brother of alkene metathesis, it allows problems to be solved that are currently beyond reach of the more famous sibling. This notion is exemplified by the tulearin macrolides, which could only be selectively forged by ring-closing alkyne metathesis (RCAM)/transreduction using the latest generation of alkyne metathesis catalysts.
- Lehr, Konrad,Mariz, Ronaldo,Leseurre, Lucie,Gabor, Barbara,Fuerstner, Alois
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supporting information; experimental part
p. 11373 - 11377
(2012/01/11)
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- Pheromones and analogs from Neozeleboria wasps and the orchids that seduce them: a versatile synthesis of 2,5-dialkylated 1,3-cyclohexanediones
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Chiloglottone, a wasp pheromone and attractant of sexually deceptive Chiloglottis orchids, and several structural analogs were synthesized. The synthetic approach is facile, high yielding and versatile, enabling rapid divergence to generate dialkylated analogs of chiloglottone. The key transformation was an organocadmium-mediated desymmetrization of glutaric anhydride derivatives. This library of synthetic 2,5-dialkylated 1,3-cyclohexanediones may assist in future identification of natural products in further species.
- Poldy, Jacqueline,Peakall, Rod,Barrow, Russell A.
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p. 2446 - 2449
(2008/09/20)
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- Process for the preparation of carboxylic acids and derivatives of them
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The subject matter of the invention is a process for the preparation of carboxylic acids and derivatives of them of the general formula STR1 wherein R means hydrogen, or a C1-4 alkyl or a (C1-5 alkoxy)carbonyl group, R1 is as defined in claim 1, R7 stands for hydrogen or a C1-7 alkyl group and R8 means hydrogen or a carboxyl group, by reacting a 1,3-dioxane-4,6-dione derivative of the general formula STR2 wherein R9 stands for a C1-4 alkyl group or a phenyl group, optionally monosubstituted by halogen and R10 stands for hydrogen or a C1-5 alkyl group or R9 and R10 together form a pentamethylene group, and an aldehyde or ketone of the general formula STR3 in the presence of formic acid.
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- Process for the preparation of carboxylic acids and derivatives of them
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The subject matter of the invention is a process for the preparation of carboxylic acids and derivatives of them of the general formula wherein Rmeans hydrogen, or a C1 4alkyl or a (C1 5alkoxy)carbonyl group, R1is as defined in claim 1, R7stands for hydrogen or a C1 7alkyl group and R8means hydrogen or a carboxyl group, by reacting a 1,3-dioxane-4,6-dione derivative of the general formula wherein R9stands for a C1 4alkyl group or a phenyl group, optionally monosubstituted by halogen and R10stands for hydrogen or a C1 5alkyl group or R9 and R10together form a pentamethylene group, and an aldehyde or ketone of the general formula in the presence of formic acid and of [a] amine(s) and, if desired, of an alcohol of the general formula, , R7 - OH VI,, , wherein R7is a C1 7alkyl group, at a temperature of 20 to 140°C, and/or, reducing an unsaturated 1,3-dioxane-4,6-dione derivative of the general formula and/or, a 1,3-dioxane-4,6-dione derivative of the general formula with formic acid in the presence of [a] amine(s) and, if desired, of an alcohol as above defined.
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- SYNTHESIS OF 3-METHYLGLUTARIC ACID
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4-Methyltetrahydropyran has been synthetized by catalytic hydrogenation of a mixture of the isomeric 4-methyl-5,6-dihydro- and 4-methylenetetrahydropyrans.Oxidative degradation then led to 3-methylglutaric acid.
- Ibatullin, U. G.,Syurina, L. V.,Vasi'leva, S. A.,Safarov, M. G.
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- Preparation of alpha, beta-unsaturated carbonyl compounds
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Alpha, beta carbonyl compounds are prepared from an acid anhydride selected from the group consisting of glutaric anhydride and 3-alkyl glutaric anhydride, and a beta-hydroxy carbonyl compound having the following chemical formula: The process comprises: (a) reacting the acid anhydride and the beta-hydroxy carbonyl compound in the presence of a catalytically effective amount of an acid catalyst to form an ester; (b) reacting the ester in the presence of a catalytically effective amount of a base catalyst to form a alpha, beta-unsaturated carbonyl compound and a carboxylic acid; and (c) separating the alpha, beta-unsaturated carbonyl compound and the carboxylic acid.
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- 1,1-Alkanediol dicarboxylate linked antibacterial agents
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Useful antibacterial agents in which a penicillin and/or a beta-lactamase inhibitor are linked via 1,1-alkanediol dicarboxylates are of the formula STR1 where A is the residue of certain dicarboxyic acids, R3 is H or (C1 -C3), n is zero or 1 such that when n is zero R is P or B and R1 is the residue of certain esters, H or a salt thereof; and when n is 1, one of R and R1 is P and the other is B, and P is STR2 where R2 is H or certain acyl groups, and B is the residue of a beta-lactamase inhibiting carboxylic acid; a method for their use, pharmaceutical compositions thereof and intermediates useful in their production.
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- Bis-esters of dicarboxylic acids with amoxicillin and certain hydroxymethylpenicillanate 1,1-dioxides
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Antibacterial bis-esters of 1,4-cyclohexanedicarboxylic acids and alkane dicarboxylic acids wherein the ester moieties are derived from different alcohols; one alcohol being hydroxymethylpenicillanate 1,1-dioxide, or the 6-beta-hydroxymethyl or the 6-alpha-aminomethyl derivative thereof; and the other being 6-[D-(2-amino-2-(p-hydroxyphenyl)acetamido)]penicillanic acid (amoxicillin); and pharmaceutically acceptable salts thereof; a method for the use of said esters and their salts, and methods for their preparation.
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- Reaction of Dinitrogen Tetraoxide with Hydrophilic Olefins: Synthesis of Citric and 2-Hydroxy-2-methylbutanedioic Acids
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Liquid olefins typically react with N2O4 by free-radical reactions to form dinitro and nitronitrite derivatives.Introduction of hydrophilic substituents into 1-olefins altered the course of the reaction of the olefins with N2O4 in aqueous HNO3.Citric acid was formed in 64 mol percent yield by the reaction of 3-methylene-1,5-pentanediol with N2O4 in aqueous HNO3.Similarly, 2-hydroxy-2-methylbutanedioic acid was made from 3-methyl-3-buten-1-ol in 88percent yield.These results are explained by solution of the hydrophilic olefins in aqueous HNO3-N2O4 and addition of N2O4 to the double bond as NO+ and NO3- ions to yield nitrosonitrates, which react further to give the final products.
- Wilkes, John B.,Wall, Robert G.
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p. 247 - 250
(2007/10/02)
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