cas 18289-89-9, (R)-Methyl 2,3-dihydroxypropanoate

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Aromatic Donor-Acceptor Interaction-Based Co(III)-salen Self-Assemblies and Their Applications in Asymmetric Ring Opening of Epoxides
Aromatic donor-acceptor interaction as the driving force to assemble cooperative catalysts is described. Pyrene/naphthalenediimide functionalized Co(III)-salen complexes self-assembled into bimetallic catalysts through aromatic donor-acceptor interactions and showed high catalytic activity and selectivity in the asymmetric ring opening of various epoxides. Control experiments, nuclear magnetic resonance (NMR) spectroscopy titrations, mass spectrometry measurement, and X-ray crystal structure analysis confirmed that the catalysts assembled based on the aromatic donor-acceptor interaction, which can be a valuable noncovalent interaction in supramolecular catalyst development.
Liang, Jian,Soucie, Luke N.,Blechschmidt, Daniel R.,Yoder, Aaron,Gustafson, Addie,Liu, Yu
supporting information
p. 513 - 518
(2019/01/14)

An Esterase-like Lyase Catalyzes Acetate Elimination in Spirotetronate/Spirotetramate Biosynthesis
Spirotetronate and spirotetramate natural products include a multitude of compounds with potent antimicrobial and antitumor activities. Their biosynthesis incorporates many unusual biocatalytic steps, including regio- and stereo-specific modifications, cyclizations promoted by Diels–Alderases, and acetylation-elimination reactions. Here we focus on the acetate elimination catalyzed by AbyA5, implicated in the formation of the key Diels–Alder substrate to give the spirocyclic system of the antibiotic abyssomicin C. Using synthetic substrate analogues, it is shown that AbyA5 catalyzes stereospecific acetate elimination, establishing the (R)-tetronate acetate as a biosynthetic intermediate. The X-ray crystal structure of AbyA5, the first of an acetate-eliminating enzyme, reveals a deviant acetyl esterase fold. Molecular dynamics simulations and enzyme assays show the use of a His-Ser dyad to catalyze either elimination or hydrolysis, via disparate mechanisms, under substrate control.
Lees, Nicholas R.,Han, Li-Chen,Byrne, Matthew J.,Davies, Jonathan A.,Parnell, Alice E.,Moreland, Pollyanna E. J.,Stach, James E. M.,van der Kamp, Marc W.,Willis, Christine L.,Race, Paul R.
supporting information
p. 2305 - 2309
(2019/01/29)

Direct conversion of C6 sugars to methyl glycerate and glycolate in methanol
The present work deals with the one-pot conversion of C6 sugars to methyl glycerate and glycolate via a cascade of retro-aldol condensation and oxidation processes catalyzed by using MoO3 as the Lewis acid catalyst and Au/TiO2 as the oxidation catalyst in methanol. Methyl glycerate (MGLY) is the product of C6 ketose (fructose), while methyl glycolate (MG) is produced from C6 aldose (mannose, glucose). It is found that a good one-pot match between two reactive processes is the key to the production of MGLY and MG with high yield (27.6% MGLY and 39.2% MG). A separated retro-aldol condensation and oxidation process greatly decreases their yields, and even no MGLY can be obtained in this separated process. We attribute this to high instability of glyceraldehyde/glycolaldehyde and their different reaction pathways which mainly depend on whether acetalization of retro-aldol products (glyceraldehyde and glycolaldehyde) occurs with methanol or not. This result opens a new prospect on the accumulation of C3 products other than lactate from biomass-derived carbohydrates.
Feng, Lei,Li, Gang,Yan, Yueer,Hou, Wenrong,Zhang, Yahong,Tang, Yi
p. 30163 - 30170
(2018/09/11)

A Native Ternary Complex Trapped in a Crystal Reveals the Catalytic Mechanism of a Retaining Glycosyltransferase
Glycosyltransferases (GTs) comprise a prominent family of enzymes that play critical roles in a variety of cellular processes, including cell signaling, cell development, and host-pathogen interactions. Glycosyl transfer can proceed with either inversion
Albesa-Jov, David,Mendoza, Fernanda,Rodrigo-Unzueta, Ane,Gomolln-Bel, Fernando,Cifuente, Javier O.,Urresti, Saioa,Comino, Natalia,Gmez, Hansel,Romero-Garca, Javier,Lluch, Jos M.,Sancho-Vaello, Enea,Biarns, Xevi,Planas, Antoni,Merino, Pedro,Masgrau, Laura,Guerin, Marcelo E.
supporting information
p. 9898 - 9902
(2015/08/19)

Characterization of QmnD3/QmnD4 for double bond formation in quartromicin biosynthesis
In this work, two enzymes responsible for the biogenesis of possible [4 + 2] reaction precursors in the quartromicin biosynthetic pathway were characterized: acetylation of 1 to yield 2 was catalyzed by QmnD3, and subsequent acetic acid elimination of 2 to form double bond product 3 was catalyzed by QmnD4. Site-directed mutagenesis assay of QmnD3 and QmnD4 was investigated, and a general base-catalyzed mechanism for QmnD4 is proposed.
Wu, Long-Fei,He, Hai-Yan,Pan, Hai-Xue,Han, Li,Wang, Renxiao,Tang, Gong-Li
supporting information
p. 1578 - 1581
(2014/04/17)

A broadly applicable and practical oligomeric (salen)Co catalyst for enantioselective epoxide ring-opening reactions
The (salen)Co catalyst (4a) can be prepared as a mixture of cyclic oligomers in a short, chromatography-free synthesis from inexpensive, commercially available precursors. This catalyst displays remarkable enhancements in reactivity and enantioselectivity relative to monomeric and other multimeric (salen)Co catalysts in a wide variety of enantioselective epoxide ring-opening reactions. The application of catalyst 4a is illustrated in the kinetic resolution of terminal epoxides by nucleophilic ring-opening with water, phenols, and primary alcohols; the desymmetrization of meso epoxides by addition of water and carbamates; and the desymmetrization of oxetanes by intramolecular ring opening with alcohols and phenols. The favorable solubility properties of complex 4a under the catalytic conditions facilitated mechanistic studies, allowing elucidation of the basis for the beneficial effect of oligomerization. Finally, a catalyst selection guide is provided to delineate the specific advantages of oligomeric catalyst 4a relative to (salen)Co monomer 1 for each reaction class.
White, David E.,Tadross, Pamela M.,Lu, Zhe,Jacobsen, Eric N.
supporting information
p. 4165 - 4180
(2014/06/09)

Efficient synthesis of dissymmetric malonic acid S, O -esters via monoalcoholysis of symmetric dithiomalonates under neutral conditions
A novel method for the highly selective synthesis of dissymmetric S,O-malonates starting from symmetric diphenyl dithiomalonates under neutral conditions is described. The key step is the thermal formation of an acylketene, the stability of which would co
Matsuo, Kazumasa,Shindo, Mitsuru
supporting information; experimental part
p. 4406 - 4409
(2011/10/08)

Orthogonally protected glycerols and 2-aminodiols: Useful building blocks in heterocyclic chemistry
The efficient synthesis of orthogonally protected glycerols, 2-aminopropane-1,3-diols and 2-aminobutane-1,4-diols that can constitute useful tools in heterocyclic chemistry, is reported. These interesting tri-functionalized small synthons were easily prepared from serine or aspartic acid. In addition, these substrates can be readily transformed into their iodide derivatives in very good yields. ARKAT USA, Inc.
Ollivier, Anthony,Goubert, Marlene,Tursun, Ahmatjan,Canet, Isabelle,Sinibaldia, Marie-Eve
scheme or table
p. 108 - 126
(2010/10/03)

Synthetic studies towards 4,10-diaza-1,7-dioxaspiro[5.5]undecanes: access to 3-aza-6,8-dioxabicyclo[3.2.1]octan-2-one and 2H-1,4-oxazin-3(4H)-one frameworks
Synthetic approaches towards 4,10-diaza-1,7-dioxaspiro[5.5]undecanes starting from 1,3-dichloroacetone and solketal derivatives are explored. The method relies on the preparation of a key bis-substituted dihydroxy-protected oxime, which would undergo a final acidic deprotection-spiroacetalization process. Although the desired diazaspiroketal framework could not be obtained, our conditions led to the unexpected 3-aza-6,8-dioxabicyclo[3.2.1]octan-2-one 18 or to the oxazinone 32 in good yields.
Goubert, Marlène,Toupet, Lo?c,Sinibaldi, Marie-Eve,Canet, Isabelle
p. 8255 - 8266
(2008/02/08)

d- and l-Serine, useful synthons for the synthesis of 24-hydroxyvitamin D3 metabolites. A formal synthesis of 1α,24R,25-(OH)3-D3, 24R,25-(OH)2-D3 and 24S,25-(OH)2-D3
d- and l-Serine have been used for the enantioselective synthesis of tosylates 7a and 7b, useful building blocks for the synthesis of triols 5a and 5b which have already been obtained via a diastereoselective synthesis and used for the synthesis of 2a, 2b and 2c. We have thus performed a formal synthesis of 24S,25-(OH)2-D3, 24R,25-(OH)2-D3 and 1α,24R,25-(OH)3-D3.
Fernandez, Carlos,Gándara, Zoila,Gómez, Generosa,Covelo, Berta,Fall, Yagamare
p. 2939 - 2942
(2008/02/03)

Hydrolytic kinetic resolution of epoxides catalyzed by chromium(III)-endo, endo-2,5-diaminonorbornane-salen [Cr(III)-DIANANE-salen] complexes. Improved activity, low catalyst loading
The hydrolytic kinetic resolution (HKR) of terminal epoxides, using chiral chromium(III)-salen catalysts based on DIANANE (endo,endo-2,5-diaminonorbornane) , was studied. A broad substrate scope was found for the chromium(III)-DIANANE catalysts, and very low loadings (down to 0.05 mol%) were needed to achieve high enantiomeric purities of both the remaining epoxides and the product diols (up to >99% ee). Besides monosubstituted epoxides, 2-methyl-2-n-pentyloxirane, which is an example for 2,2-disubstituted epoxides, could be ring-opened in an asymmetric fashion with water in the presence of an electronically tuned chromium-(III)-DIANANE complex.
Berkessel, Albrecht,Ertuerk, Erkan
p. 2619 - 2625
(2007/10/03)

Acetal phosphate-derived LPA mimics, PPARgamma activators, and autotaxin inhibitors
Disclosed are compositions that modulate the effects of extracellular LPA receptors, the intracellular PPARγ receptor, and autotaxin, and methods for their use.
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(2010/11/24)

Identification of Darmstoff analogs as selective agonists and antagonists of lysophosphatidic acid receptors
Darmstoff describes a family of gut smooth muscle-stimulating acetal phosphatidic acids initially isolated and characterized from the bath fluid of stimulated gut over 50 years ago. Despite similar structural and biological profiles, Darmstoff analogs have not previously been examined as potential LPA mimetics. Here, we report a facile method for the synthesis of potassium salts of Darmstoff analogs. To understand the effect of stereochemistry on lysophosphatidic acid mimetic activity, synthesis of optically pure stereoisomers of selected Darmstoff analogs was achieved starting with chiral methyl glycerates. Each Darmstoff analog was evaluated for subtype-specific LPA receptor agonist/antagonist activity, PPARγ activation, and autotaxin inhibition. From this study we identified compound 12 as a pan-antagonist and several pan-agonists for the LPA1-3 receptors. Introduction of an aromatic ring in the lipid chain such as analog 22 produced a subtype-specific LPA3 agonist with an EC50 of 692 nM. Interestingly, regardless of their LPA1/2/3 ligand properties all of the Darmstoff analogs tested activated PPARγ. However, these compounds are weak inhibitors of autotaxin. The results indicate that Darmstoff analogs constitute a novel class of lysophosphatidic acid mimetics.
Gududuru, Veeresa,Zeng, Kui,Tsukahara, Ryoko,Makarova, Natalia,Fujiwara, Yuko,Pigg, Kathryn R.,Baker, Daniel L.,Tigyi, Gabor,Miller, Duane D.
p. 451 - 456
(2007/10/03)

NOVEL HETEROARYL DERIVATIVE
A heteroaryl derivative of the formula (1): (wherein Ring Z is an optionally substituted heteroaryl, R1 is a carboxyl group or an alkoxycarbonyl group, etc., W1 and W2 are an optionally substituted lower alkylene, Ar1 is an optionally substituted arylene or an optionally substituted heteroarylene, W3 is a single bond, a lower alkylene, a lower alkenylene, etc., W4 is a single bond, -NR10-, etc., Ar2 is an optionally substituted aryl or an optionally substituted heteroaryl), or a prodrug thereof, or a pharmaceutically acceptable salt thereof.
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(2008/06/13)

Mechanistic Investigation Leads to a Synthetic Improvement in the Hydrolytic Kinetic Resolution of Terminal Epoxides
The mechanism of the hydrolytic kinetic resolution (HKR) of terminal epoxides was investigated by kinetic analysis using reaction calorimetry. The chiral (salen)Co-X complex (X = OAc, OTs, Cl) undergoes irreversible conversion to (salen)Co-OH during the course of the HKR and thus serves as both precatalyst and cocatalyst in a cooperative bimetallic catalytic mechanism. This insight led to the identification of more active catalysts for the HKR of synthetically useful terminal epoxides. Copyright
Nielsen, Lars P. C.,Stevenson, Christian P.,Blackmond, Donna G.,Jacobsen, Eric N.
p. 1360 - 1362
(2007/10/03)

Highly selective hydrolytic kinetic resolution of terminal epoxides catalyzed by chiral (salen)CoIII complexes. Practical synthesis of enantioenriched terminal epoxides and 1,2-diols
The hydrolytic kinetic resolution (HKR) of terminal epoxides catalyzed by chiral (salen)CoIII complex 1·OAc affords both recovered unreacted epoxide and 1,2-diol product in highly enantioenriched form. As such, the HKR provides general access to useful, highly enantioenriched chiral building blocks that are otherwise difficult to access, from inexpensive racemic materials. The reaction has several appealing features from a practical standpoint, including the use of H2O as a reactant and low loadings (0.2-2.0 mol %) of a recyclable, commercially available catalyst. In addition, the HKR displays extraordinary scope, as a wide assortment of sterically and electronically varied epoxides can be resolved to ≥ 99% ee. The corresponding 1,2-diols were produced in good-to-high enantiomeric excess using 0.45 equiv of H2O. Useful and general protocols are provided for the isolation of highly enantioenriched epoxides and diols, as well as for catalyst recovery and recycling. Selectivity factors (krel) were determined for the HKR reactions by measuring the product ee at ca. 20% conversion. In nearly all cases, krel values for the HKR exceed 50, and in several cases are well in excess of 200.
Schaus, Scott E.,Brandes, Bridget D.,Larrow, Jay F.,Tokunaga, Makoto,Hansen, Karl B.,Gould, Alexandra E.,Furrow, Michael E.,Jacobsen, Eric N.
p. 1307 - 1315
(2007/10/03)

A convenient synthesis of dibenzyl α,α-difluoromethyl-β-ketophosphonates
The first synthesis of dibenzyl α,α-difluoro-β-ketophosphonates has been accomplished by an original fluorination reaction, namely addition of the F+ ion to the enolate form of the corresponding dibenzyl β-ketophosphonate. After an easy cleavag
Ladame, Sylvain,Willson, Michele,Perie, Jacques
p. 2640 - 2648
(2007/10/03)

A β-lactam-based stereoselective access to β,γ-dihydroxy α-amino acid-derived peptides with either α,β-like or unlike configurations
A concise access to α,β-dihydroxy α-amino acid-derived N-carboxy anhydrides (NCAs) with either like or unlike relative configuration is described. The key steps of the synthetic route are the preparation of the nonracemic 4-alkenyl β-lactams, through either Homer-type olefination of a common 4-formyl β-lactam or the Corey-Winter alkene synthesis applied to 4-dihydroxyalkyl β-lactams, followed by the Sharpless AD reaction, and a subsequent ring expansion of the corresponding 4-substituted 3-hydroxy β-lactams promoted by TEMPO. The opening of thus-prepared NCAs upon treatment with different O- and N-nucleophiles, including α-amino esters which lead to peptides, has also been studied under various reaction conditions.
Palomo,Oiarbide,Landa,Esnal,Linden
p. 4180 - 4186
(2007/10/03)

A cross metathesis-based synthesis of analogues of the 2-O-alkyl glycerate part of the moenomycins
Conditions are reported which allow to convert optically active methyl glycerate to the 2-O-allyl derivative without racemization. Cross metathesis reactions then lead to analogues of the 2-O-alkyl glycerate part of the moenomycin antibiotics.
Eichelberger, Uwe,Mansourova, Madina,Hennig, Lothar,Findeisen, Matthias,Giesa, Sabine,Müller, Dietrich,Welzel, Peter
p. 9737 - 9742
(2007/10/03)

Asymmetric synthesis of a 3-acyltetronic acid derivative, RK-682, and formation of its calcium salt during silica gel column chromatography
RK-682 was reported to be a potent protein tyrosine phosphatase inhibitor. We found that (R)-3-hexadecanoyl-5-hydroxymethyltetronic acid (I) was easily converted to its calcium salt during column chromatography on Silica gel 60, and this calcium salt was identical to RK-682 originally isolated from a natural source. Here we report details of the asymmetric synthesis of (R)-I and its conversion to the calcium salt. Fast atom bombardment mass spectrometric (FAB-MS) analysis of the free and calcium salt forms of RK-682 is also reported.
Sodeoka,Sampe,Kojima,Baba,Morisaki,Hashimoto
p. 206 - 212
(2007/10/03)

A new approach to the stereospecific synthesis of phospholipids. The use of L-glyceric acid for the preparation of diacylglycerols, phosphatidylcholines, and related derivatives
A new stereospecific synthesis of phospholipid derivatives of 1,2- diacyl-sn-glycerols is reported. The synthesis is based on (1) the use of L- glyceric acid as the stereocenter for construction of the optically active phospholipid molecule, (2) preparation of 3-triphenylmethyl-sn-glycerol as the key intermediate for sequential introduction of the primary and secondary acyl functions leading to the chiral diglycerides, and (3) elaboration of the sn-3-phosphodiester headgroup via phosphorylation using 2-chloro-2-oxo-1,3,2- dioxaphospholane, followed by ring opening of the five-membered phosphorus heterocycle with trimethylamine, ammonia, as well as oxygen and sulfur nucleophiles. The sequence has been shown to be suitable for the preparation of both symmetric and mixed-chain diacylglycerols with saturated and unsaturated acyl substituents. Phospholipid headgroups including phosphocholine, phosphoethanolamine, phosphoethanol, and phosphoethylthioacetate functions have been prepared. Application of the method to the synthesis of functionalized phosphatidylcholines has also been demonstrated by incorporating spectroscopically active spin-labeled and fluorescent reporter groups via postsynthetic derivatization of chain terminal ω-aminoalkyl functions of the acyl substituents of the compounds. The synthetic methods developed have a great deal of flexibility, providing convenient routes to a wide range of structurally variable phospholipids for physicochemical, enzymological, and cell-biological studies.
Roodsari, Farzaneh S.,Wu, Dongpei,Pum, Gregory S.,Hajdu, Joseph
p. 7727 - 7737
(2007/10/03)

The effect of cesium fluoride-DMF in the dibutylstannylene acetal-mediated selective monobenzylation of methyl 2,3-D-glycerate
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Arukwe, Joseph
p. 819 - 823
(2007/10/03)

Asymmetric synthesis of RK-682 and its analogs, and evaluation of their protein phosphatase inhibitory activities
We report an asymmetric synthesis of a potent tyrosine phosphatase inhibitor, RK-682 and its analogs. The absolute stereochemistry of RK-682 was determined to be (R). The inhibitory activities of RK-682 and its analogs, (R)-1a, (S)-1a, (R)-1b and (R)-1c toward various protein phosphatases (VHR, cdc25A, cdc25B, and PPI) are also reported.
Sodeoka, Mikiko,Sampe, Ruriko,Kagamizono, Terumi,Osada, Hiroyuki
p. 8775 - 8778
(2007/10/03)

Enzymatic Synthesis of Chiral Monosubstituted Malonates in Organic Solvents
Prochiral stereospecificity of enzymes in organic solvents was used to develop a strategy for the formation of heretofore unknown chiral monosubstituted malonate diesters with high enantiomeric excess.The enzymatic reaction involved transesterification of symmetrical monosubstituted dimethyl malonates with benzyl alcohol, exploiting the ability of lipases to discriminate between the enantiotopic ester groups of the symmetrical malonate molecule.This enzymatic approach is not feasible in aqueous solutions because the activated malonic hydrogen invariably undergoes fast exchange accompanied by racemisation.The synthetic utility of this method was further demonstrated by converting the configurationally unstable mixed methyl benzyl diesters into the corresponding half esters, which were in turn selectively reduced into configurationally stable and synthetically useful hydroxyesters.
Shapira, Michal,Gutman, Arie L.
p. 1689 - 1700
(2007/10/02)

Determination of the absolute configuration of the glycerol component in poly(glycosylglycerolphosphates) by GLC-MS
Assignment of the stereochemistry of the glycerol residue in poly(glycosyl-glycerol phosphates) may be achieved by release of the chiral glycerol component, followed by its conversion to an appropriate derivative, and assignment of absolute stereochemistry by comparison with standards of known chirality.
Beynon,Richards
p. 263 - 268
(2007/10/02)

Antiviral and Antitumor Structure-Activity Relationship Studies on Tetracyclic Eudistomines
The in vitro antiviral and antitumor activities of (-)-debromoeudistomin K (1a) and 10 structural analogues (1b-1j and 11) were evaluated.The synthesis was accomplished with an intramolecular Pictet-Spengler condensation reaction as the key step.This exam
Maarseveen, Jan H. Van,Hermkens, Pedro H. H.,Clercq, Erik De,Balzarini, Jan,Scheeren, Hans W.,Kruse, Chris G.
p. 3223 - 3230
(2007/10/02)

Syntheses of heparin - like pentamers containing "opened" uronic acid moieties
The syntheses of four analogues of pentasaccharide Ia, which corresponds to the minimal AT III binding region of heparin, are presented and the biological activities of these analogues will be discussed. Three of these analogues (i.e. compounds II, III an
Lucas,Hasten,Van Dinther,Meuleman,Van Aelst,Van Boeckel
p. 8207 - 8228
(2007/10/02)

Intermediates for preparing optically active carboxylic acids
A process is described for preparing optically active alpha-arylalkanoic acids consisting of rearranging an optically active ketal of formula STR1 in which the substituents have the meaning given in the description of the invention.
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(2008/06/13)

Eine synthetische, heparin-aehnliche Verbindung, die Antithrombin III aktiviert, obwohl sie ein offenkettiges Fragment an Stelle der &α-L-Idopyranuronsaeure enthaelt
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Boeckel, Constant A. A. van,Basten, Jan E. M.,Lucas, Hans,Aelst, Sjoerd F. van
p. 1217 - 1218
(2007/10/02)

STEREOSPECIFIC SYNTHESIS OF 2-THIOPHOSPHATIDYLCHOLINES; A NEW CLASS OF BIOLOGICALLY ACTIVE PHOSPHOLIPID ANALOGUES
A new stereospecific synthesis of biologically active sn-2-thiophosphatidylcholines is reported.
Bhatia, Suresh K.,Hajdu, Joseph
p. 3767 - 3770
(2007/10/02)

Synthesis and Determination of the Enantiomeric Pyrity of (R)- and (S)-2,3-Dihydroxy-3-methylbutyl p-Toluensulfonate
(R)- and (S)-2,3-dihydroxy-3-methylbutyl p-toluenesulfonate, used as building blocks for vitamine D3 metabolites and carotenoids, respectively, were resynthesized since differing melting points and optical rotations are reported in the literature.The give
Schoenecker, Bruno
p. 705 - 712
(2007/10/02)