79-33-4Relevant articles and documents
Asymmetric Synthesis of Optically Active 3-Cyclohexene-1-carboxylic Acid Utilizing Lactic Ester as a Chiral Auxiliary in the Diastereoselective Diels–Alder Reaction
Fujita, Ryunosuke,Hayashi, Wakana,Kubota, Shunichi,Nishi, Tatsuya,Nishiyama, Akira,Ochiai, Hidenori,Sasagawa, Miwa
supporting information, (2022/02/09)
The optically active 3-cyclohexene-1-carboxylic acid was synthesized through a TiCl4-catalyzed diastereoselective Diels–Alder reaction utilizing lactic acid ester as a chiral auxiliary, which can be removed by washing with H2O. The (S)- and (R)-isomers were both derived from easily available ethyl l-lactate.
γ-Valerolactone-introduced controlled-isomerization of glucose for lactic acid production over an Sn-Beta catalyst
Zhao, Xinpeng,Zhou, Zhimin,Luo, Hu,Zhang, Yanfei,Liu, Wang,Miao, Gai,Zhu, Lijun,Kong, Lingzhao,Li, Shenggang,Sun, Yuhan
supporting information, p. 2634 - 2639 (2021/04/22)
Combined experiments and density functional theory (DFT) calculations provided insights into the role of environment-friendly γ-valerolactone (GVL) as a solvent in the hydrothermal conversion of glucose into lactic acid (LA) over the post-synthesized Sn-Beta catalyst. By introducing 2.0 wt% GVL, a much higher yield of LA (72.0 wt%) was obtained than that in pure water (60.1 wt%) at 200 °C, 4 MPa N2, and 30 min in a batch reactor. The GVL effectively suppressed the isomerization of glucose into fructose in a controlled-transfer mode, resulting in a lower fructose concentration. Thermogravimetry-differential analysis and DFT calculations demonstrated that the competitive adsorption between GVL and glucose happened at the open Sn sites over the Sn-Beta catalyst, which led to a controlled isomerization rate in water. Further increasing the content of GVL to 20.0 wt%, the higher yield of LA (74.0 wt%) was attributed to the more efficient competitive adsorption while also inhibiting carbon deposition.
METHODS FOR SYNTHESIZING ANHYDROUS LACTIC ACID
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Paragraph 0038; 0056, (2021/11/13)
A method of synthesizing anhydrous lactic acid is provided by reacting a compound of formula (Ia): with an acid compound of formula HnX in a first solvent to produce a reaction mixture comprising a compound of formula (Ib) and a lactic acid compound of formula (I) in solution with the first solvent and/or water. n is an integer other than 0, x is 0, or an integer other than 0, M is an alkali metal or alkaline earth metal and X is the conjugate base of the acid compound of formula HnX. The resulting reaction mixture is filtered to produce a filtrate containing lactic acid in solution. The filtrate is crystalized from a second solvent to produce anhydrous lactic acid.
Discovery, Total Synthesis, and SAR of Anaenamides A and B: Anticancer Cyanobacterial Depsipeptides with a Chlorinated Pharmacophore
Brumley, David A.,Chen, Qi-Yin,Gunasekera, Sarath P.,Luesch, Hendrik,Paul, Valerie J.
, p. 4235 - 4239 (2020/06/27)
New modified depsipeptides and geometric isomers, termed anaenamides A (1a) and B (1b), along with the presumptive biosynthetic intermediate, anaenoic acid (2), were discovered from a marine cyanobacterium from Guam. Structures were confirmed by total synthesis. The alkylsalicylic acid fragment and the C-terminal α-chlorinated α,β-unsaturated ester are novelties in cyanobacterial natural products. Cancer cell viability assays indicated that the C-terminal unit serves as the pharmacophore and that the double-bond geometry impacts the cytotoxicity.
Epimerization-suppressed organocatalytic synthesis of poly-L-lactide in supercritical carbon dioxide under plasticizing conditions
Mase, Nobuyuki,Moniruzzaman,Yamamoto,Sato,Narumi, Tetsuo,Yanai, Hikaru
supporting information, (2019/08/06)
Herein, an efficient (>95% yield, >99.0% ee) Br?nsted acid-catalyzed synthetic method of poly-L-lactide (PLLA) in supercritical carbon dioxide (scCO2) under plasticizing conditions is presented. High-performance liquid chromatography analysis of the PLLA hydrolysis products indicated that, as opposed to the case of organic solvents, the use of a nucleophilic catalyst in scCO2 suppressed the epimerization. The highly stereochemically pure PLLA prepared by the developed method under metal-free conditions meets the criteria of medicinal/engineering applications.
Polyoxomolybdates catalysed cascade conversions of cellulose to glycolic acid with molecular oxygen via selective aldohexoses pathways (an epimerization and a [2+4] Retro-aldol reaction)
Bayu, Asep,Karnjanakom, Surachai,Yoshida, Akihiro,Kusakabe, Katsuki,Abudula, Abuliti,Guan, Guoqing
, p. 28 - 34 (2018/05/28)
Selective cascade conversion of cellulose into valuable C2 or C4 products over acid catalysts is still not fully explored because glucose-fructose isomerization followed by fructose conversions is thermodynamically easy to occur during the reaction, leading the formation of C6, C5, C3 and C1 products such as 5-hydroxymethylfurfural (HMF), levulinates, lactates, formates, and so on. In this study, phosphomolybdates (PMo) with the Keggin structure was found to promote cascade oxidation of cellulose conversion via selective aldohexoses pathways, i.e. an epimerization and a [2 + 4] retro-aldol of glucose/mannose, rather than aldo-ketohexoses routes, i.e. a glucose-fructose isomerization and a [3 + 3] retro-aldol of fructose, which produced glycolic acid (GlycA) (C2) as the main product (～50% selectivity). Either in aerobic or anaerobic state, PMo selectively catalyzed glucose epimerization into mannose at 100 °C. This behavior is completely different from that of molybdate in MoO3 which is only effective for the epimerization reaction (the Bilik reaction). In this cascade oxidation reaction, PMo was reduced into heteropoly-blue (PMored) as observed by the color change of the solution, UV-VIS and FT-IR measurements. In this case, the molecular oxygen was found to reoxidize PMored into PMo, leading the catalytic activity to be remained stable. The results shown in this study provide an insight for the catalyst development on selective synthesis of C2, C4 and/or other novel valuable chemicals from carbohydrates via the aldohexose pathways.
Chiron approach towards optically pure γ-valerolactone from alanine
Datrika, Rajender,Kallam, Srinivasa Reddy,Katta, Rambabu,Siddaiah, Vidavalur,Pratap
supporting information, p. 2801 - 2808 (2018/12/04)
A concise synthesis of both enantiomers of γ-valerolactone has been developed from commercially available Alanine. The key steps in the synthesis of these γ-Lactones are DIBAL-H reduction of ester (9) followed by in situ Wittig reaction with EtO2CCH = PPh3 ylide (13) (Z/E = 1: 3.5) and one pot lactonization triggered by deprotection of O-TBS ether (14).
Characterization of methylated azopyridine as a potential electron transfer mediator for electroenzymatic systems
Tetianec, Lidija,Chaleckaja, Ana,Kulys, Juozas,Janciene, Regina,Marcinkeviciene, Liucija,Meskiene, Rita,Stankeviciute, Jonita,Meskys, Rolandas
, p. 41 - 48 (2017/06/05)
N,N'-dimethyl-4,4'-azopyridinium methyl sulfate (MAZP) was characterized as an electron transfer mediator for oxidation reactions catalyzed by NAD+- and pyrroloquinoline quinone (PQQ)-dependent alcohol dehydrogenases. The bimolecular rate constant of NADH reactivity with MAZP was defined as (2.2?±?0.1)?×?105?M?1?s?1, whereas the bimolecular rate constant of reactivity of the reduced form of PQQ-dependent alcohol dehydrogenase with MAZP was determined to be (4.7?±?0.1)?×?104?M?1?s?1. The use of MAZP for the regeneration of the cofactors was investigated by applying the electrochemical oxidation of the mediator. The total turnover numbers of mediator MAZP and cofactor NADH for ethanol oxidation catalyzed by NAD+-dependent alcohol dehydrogenase depended on the concentration of the substrate and the duration of the electrolysis, and the yield of the reaction was limited by the enzyme inactivation and the electrochemical process. The PQQ-dependent alcohol dehydrogenase was more stable, and the turnover number of the enzyme reached a value of 2.3?×?103. In addition, oxidation of 1,2-propanediol catalyzed by the PQQ-dependent alcohol dehydrogenase proceeded enantioselectively to yield L-lactic acid.
Metal Nanoparticles Supported on Perfluorinated Superacid Polymers: A Family of Bifunctional Catalysts for the Selective, One-Pot Conversion of Vegetable Substrates in Water
Moreno-Marrodan, Carmen,Liguori, Francesca,Barbaro, Pierluigi,Caporali, Stefano,Merlo, Luca,Oldani, Claudio
, p. 4256 - 4267 (2017/10/12)
We describe the rational design of a new versatile family of bifunctional catalytic materials based on the combination of supported metal nanoparticles (Pd, Rh, Ru) and the superacid, perfluorinated Aquivion PFSA polymer. The heterogeneous catalysts were tested in the multi-step valorisation of representative plant derivatives to high-added-value chemicals. Particularly, the conversion of (+)-citronellal to (-)-menthol and levulinic acid to γ-valerolactone was achieved in one pot and in one stage in the water phase and shows full selectivity at a high conversion level under mild reaction conditions. The results are discussed in terms of the catalyst micro-structure.
Emissive Synthetic Cofactors: An Isomorphic, Isofunctional, and Responsive NAD+ Analogue
Rovira, Alexander R.,Fin, Andrea,Tor, Yitzhak
supporting information, p. 15556 - 15559 (2017/11/14)
The synthesis, photophysics, and biochemical utility of a fluorescent NAD+ analogue based on an isothiazolo[4,3-d]pyrimidine core (NtzAD+) are described. Enzymatic reactions, photophysically monitored in real time, show NtzAD+ and NtzADH to be substrates for yeast alcohol dehydrogenase and lactate dehydrogenase, respectively, with reaction rates comparable to that of the native cofactors. A drop in fluorescence is seen as NtzAD+ is converted to NtzADH, reflecting a complementary photophysical behavior to that of the native NAD+/NADH. NtzAD+ and NtzADH serve as substrates for NADase, which selectively cleaves the nicotinamide's glycosidic bond yielding tzADP-ribose. NtzAD+ also serves as a substrate for ribosyl transferases, including human adenosine ribosyl transferase 5 (ART5) and Cholera toxin subunit A (CTA), which hydrolyze the nicotinamide and transfer tzADP-ribose to an arginine analogue, respectively. These reactions can be monitored by fluorescence spectroscopy, in stark contrast to the corresponding processes with the nonemissive NAD+.
