Tetronic Acid Research Articles

Synthesis and Crystal Structure Characterization of Zinc (II) Tetronic Acid Complexes

The synthesis and characterization of two new tetronic acid zinc (II) complexes of the empirical formulae [Zn(L–H)2(H2O)2] (1) and [Zn(L–H)2(H2O)(MeOH)]H2O (2) found within the same crystal are reported. The zinc ions bind through alkoxide and carbonyl groups of the ligand 3-methoxycarbonyl-5-phenyl tetronic acid (LH) as indicated by 1H NMR and X-ray crystallographic studies. These complexes promote intra- and intermolecular interactions, such as hydrogen bonding and π stacking, giving place to the formation of molecular aggregates.

Tetramic and Tetronic Acids as Scaffolds in Bioinorganic and Bioorganic Chemistry

Tetramic and tetronic acids are naturally occurring molecules with a variety of biological activities. In this review article, we present the general strategies for the synthesis of these compounds and we reveal the functionalized groups that are responsible for their properties. We also set out their coordinating modes with up-to-date bibliographical references.

Unexpected and Green Synthesis of Azapodophyllotoxin Derivatives via Microwave-Assisted Multicomponent Reactions in Ammonia Water

An unexpected and green synthesis of azapodophyllotoxin derivatives was realized via microwave-assisted multicomponent reactions of dimedone, tetronic acid, and aromatic aldehydes in ammonia water. This protocol has the advantages of environmental friendliness, short reaction time, good yields, low cost, and easy operation.

Stereoselective Synthesis of (E)-2-En-4-ynoic Acids with Ynolates: Catalytic Conversion to Tetronic Acids and 2-Pyrones

A highly torquoselective olefination of alkynoates to provide functionalized tetrasubstituted olefins, (E)-2-en-4-ynoic acids, is described. Addition of Brønsted acids dramatically switched the mode of the Ag(I)-catalyzed cyclization of the resulting enyne carboxylic acids to give either tetronic acids or 2-pyrones.

Clean synthesis of furo[3,4‐e]pyrazolo[3,4‐b]pyridine‐5‐one derivatives in aqueous media

Abstract magnified image A series of 4‐aryl‐3‐methyl‐1‐phenyl‐7H‐furo[3,4‐e]pyrazolo[3,4‐b]pyridine‐5‐ones were synthesized via the three‐component reaction of an aldehyde, 5‐amino‐3‐methyl‐1‐phenyl‐1H‐pyrazole and tetronic acid in aqueous media in the presence of triethylbenzylammonium chloride (TEBAC). This method has the advantages of easier work‐up, mild reaction conditions, high yields, and an environmentally benign procedure. J. Heterocyclic Chem., (2009).

ChemInform Abstract: Synthesis of Benzo[f]quinoline Derivatives by Three‐Component Condensation of Tetronic Acid with Naphthalen‐2‐amine and Formaldehyde.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

A Regioselective Tsuji-Trost Pentadienylation of 3-Allyltetronic Acid

A regioselective Tsuji-Trost reaction of sodium 3-allyltetronate with methyl 5-trimethylsilylpenta-2,4-dienyl carbonate was developed. Carbon-carbon bond formation at the more highly substituted terminus of the pentadienyl residue was possible by introduction of an easy to remove SiMe 3 shielding group at the remote end of the π-system. This carbonate reacted fast enough to avoid scrambling and formation of symmetric bisallyl tetronic acids. The 3-allyl-3-penta-2,4-dienyltetronic acid thus obtained is a key intermediate en route to the natural spirolactone bakkenolide A.

Facile and Clean Synthesis of Furopyridine Derivatives via Three-Component Reaction in Aqueous Media Without Catalyst

A series of furo[2′,1′:5,6]pyrido[2,3-d]pyrimidine derivatives were synthesized via the three-component reaction of an aldehyde, tetronic acid, and 6-amino-1,3-dimethyl-pyrimidine-2,4-dione in aqueous media without the use of catalyst. This protocol has the advantages of better yields, less cost, reduced environmental impact, and convenient procedure.

Asymmetric Synthesis, Structure, and Reactivity of Unexpectedly Stable Spiroepoxy-β-Lactones Including Facile Conversion to Tetronic Acids: Application to (+)-Maculalactone A

A novel class of small spirocyclic heterocycles, spiroepoxy-beta-lactones (1,4-dioxaspiro[2.3]-hexan-5-ones), is described that exhibit a number of interesting reactivity patterns. These spiroheterocycles, including an optically active series, are readily synthesized by epoxidation of ketene dimers (4-alkylidene-2-oxetanones) available from homo- or heteroketene dimerization. An analysis of bond lengths in these systems by X-ray crystallography and comparison to data for known spirocycles and those determined computationally suggest that anomeric effects in these systems may be more pronounced due to their rigidity and may contribute to their surprising stability. The synthetic utility of spiroepoxy-beta-lactones was explored, and one facile rearrangement identified under several conditions provides a three-step route from acid chlorides to optically active tetronic acids, ubiquitous heterocycles in bioactive natural products. The addition of various nucleophiles to these spirocycles leads primarily to addition at C5 and C2. The utility of an optically active spiroepoxy-beta-lactone was demonstrated in the concise, enantioselective synthesis of the antifouling agent, (+)-maculalactone A, which proceeds in five steps from hydrocinnamoyl chloride by way of a tetronic acid intermediate.

ChemInform Abstract: Enantioselective Synthesis of a 3,5,5‐Trialkylated Tetronic Acid Derivative.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

A facile synthesis of furo[3,4‐e]pyrazolo[3,4‐b]pyridine‐5(7H)‐one derivatives via three‐component reaction in ionic liquid without any catalyst

Abstract magnified imageA series of furo[3,4‐e]pyrazolo[3,4‐b]pyridine‐5(7H)‐one and indeno[2,1‐e]pyrazolo[3,4‐b]pyridine‐5(1H)‐one derivatives were synthesized via the three‐component reaction of an aldehyde, 5‐aminopyrazole and either tetronic acid or 1,3‐indanedione in ionic liquid without any catalyst. The structures of the products have been established by spectroscopic data and further confirmed by X‐ray diffraction analysis. This method has the advantages of easier work‐up, mild reaction conditions, high yields and an environmentally benign procedure. J. Heterocyclic Chem., 46, 469 (2009).

Cyclobutylcarbinyl Radical Fragmentation Reactions of Tetronate [2+2] Photocycloaddition Products

Cyclobutanes derived from [2+2] photocycloaddition ­reactions of tetronic acid esters were subjected to free-radical fragmentation reactions. The product formation was strongly dependent on the relative stabilities of the intermediate radicals, thus leading to either an oxepane or a methylenetetrahydrofuran in good yields.

Synthesis of vulpinic acids from dimethyl tartrate

A series of vulpinic acids differing by the aryl or heteroaryl groups placed in the ester α-position were prepared by Suzuki–Miyaura cross-coupling involving a common iodide and the corresponding aryl boronates. The preparation of the iodide precursor from (+)-dimethyl l-tartrate required four steps: the esterification of one hydroxyl group, a Dieckmann cyclization allowing the construction of the tetronic acid moiety, a dehydration leading to the installation of the exocyclic double bond and lastly, an N-iodosuccinimide-mediated iodation of the alkene obtained.

Synthesis of benzo[f]quinoline derivatives by three-component condensation of tetronic acid with naphthalen-2-amine and formaldehyde

New derivatives of benzo[f]furo[3,4-b]quinoline, spiro[benzo[f]quinoline-2,3′-furan], and benzo[f]-quinoline-2-carboxylic acid were synthesized with high selectivity by three-component condensation of tetronic acid with naphthalen-2-amine and formaldehyde.

Genetic and biochemical analysis of a laboratory‐selected spirodiclofen‐resistant strain of Tetranychus urticae Koch (Acari: Tetranychidae)

Spirodiclofen is a selective, non-systemic acaricide from the new chemical class of tetronic acid derivatives. In order to develop strategies to minimise resistance in the field, a laboratory-selected spirodiclofen-resistant strain of the two-spotted spider mite, Tetranychus urticae Koch, was used to determine genetic, toxicological, biochemical and cross-resistance data. Selecting for spirodiclofen resistance in the laboratory yielded a strain (SR-VP) with a resistance ratio of 274, determined on the larval stage. The egg stage remained far more susceptible. No cross-resistance was found against other established acaricides, except for spiromesifen. Based on synergist experiments and enzyme assays, it appeared that especially P450 monooxygenases, but also esterases and glutathione-S-transferases, could be involved in the metabolic detoxification of spirodiclofen. Genetic analysis showed that the resistance is inherited as an intermediate trait under control of more than one gene. Resistance to spirodiclofen exceeded by far the recommended field rate. A good acaricide resistance management programme is necessary to prevent fast resistance build-up in the field. Spirodiclofen can be used in alternation with most established acaricides, except for other tetronic acid derivatives. Without selection pressure, resistance tends to be unstable and can decrease in the presence of susceptible individuals owing to the intermediate, polygenic inheritance mode.

ChemInform Abstract: Tetronic Acid in Reaction with Aromatic Aldehydes and 2‐Naphthylamine. Investigation of Fluorescent and Nonlinear‐Optical Characteristics of Compounds Obtained.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Enantioselective Synthesis of a 3,5,5-Trialkylated Tetronic Acid Derivative

A convenient and enantioselective method for the synthesis of 3,5,5-trialkylated tetronic acid has been developed. The Dieckmann-type condensation of enantioenriched a-acyloxy-a,a-dialkylated acetic acid ester (11) proceeded in the presence of lithium hexamethyldisilazide, providing the expected tetronic acid derivative (12) after quenching with methoxymethyl chloride. The product (12) was converted into a doubly prenylated tetronic acid derivative (13), which constitutes a substructure of perforatumone, a newly isolated polycyclic polyprenylated acylphloroglucinol-type natural product.

Design and Microwave-Assisted Synthesis of Naphtho[2,3-f]quinoline Derivatives and Their Luminescent Properties

A sequential three-component reaction of an aromatic aldehyde with an equimolar amount of 2-aminoanthracene and cyclic 1,3-dicarbonyl compounds (such as tetronic acid, 5,5-dimethyl,3-cyclohexanedione, 1,3-indanedione, 3H-chromene-2,4-dione, quinoline-2,4(1H, 3H)-dione and barbituric acid) in acidic medium under microwave irradiation has been developed. In this one-pot reaction, a series of unusual fused heterocyclic compounds, naphtho[2,3-f]quinoline derivatives, were synthesized. This method has the advantages of operational simplicity, increased safety for small-scale fast synthesis, and minimal environmental impact. Most distinctively, this new class of naphtho[2,3-f]quinoline derivatives exhibit good luminescent properties in the ethanol solution, which can be used potentially as organic electroluminescent (EL) media.

3-Aryltetronic Acids: Efficient Preparation and Use as Precursors for Vulpinic Acids

3-Aryltetronic acids were prepared in one step by treatment of a mixture of methyl arylacetates and methyl hydroxyacetates with potassium tert-butoxide, via tandem transesterification/Dieckmann condensation. Several mushroom or lichen pigments, vulpinic acids, were synthesized from 3-(4-methoxyphenyl)tetronic acid in three steps involving the reaction of the corresponding dianion with an alpha-ketoester and the dehydration of the tertiary alcohols obtained into mixtures of (E)- and (Z)-alkenes, which were converted under UV irradiation at 254 nm to natural (E)-isomers. Syntheses of pinastric acid, 4,4'-dimethoxyvulpinic acid, and the first synthesis of recently isolated methyl 3',5'-dichloro-4,4'-di-O-methylatromentate were hence achieved in an efficient manner.

ChemInform Abstract: Synthesis of Vulpinic and Pulvinic Acids from Tetronic Acid.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.