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Since the very first resolution of racemic tartaric acid by Pasteur, the importance of resolution and methodology has been on a path of continuous understanding and expansion. The science and chemistry of achieving such targets has changed a lot. The advent of chromatography changed the direction by involving synthetic, semisynthetic, or naturally occurring chiral materials for a direct approach to resolution, where rapid and reversible association occurs to form diastereomers with different stabilities and partition coefficients responsible for overall enantioseparation. It has now reached a stage where the separation of excess enantiomers from nonracemic mixtures has been achieved in a totally achiral environment, which does not appear to be in line with the prevalent concepts of basic stereochemistry. Caution should be exercised when enantiomerically enriched mixtures – obtained by enantioselective synthesis – are chromatographed for purification in preparative organic synthesis.

A short and efficient protocol for the synthesis of β-lactam containing α-hydroxy phosphonate esters using inexpensive catalysts such as tartaric acid and fumaric acid is described.

We describe the first ring-opening of furfuryl alcohols with boronic acids to afford functionalized γ-ketoaldehydes. The transformation builds a new C–C bond at the original C-4 of the starting furan, and tolerates ring-substitution at C-3 and C-4 positions. The reaction takes place under metal-free conditions by promotion with tartaric acid.

TADDOL derivatives and the Ca(2+)-salts of tartaric acid derivatives were found to be versatile and generally applicable resolving agents for the preparation of the enantiomers of P-stereogenic heterocyclic phosphine oxides and phosphinates via the formation of the corresponding diastereomeric molecular and coordination complexes. A few of the diastereomeric intermediates were characterized by single crystal X-ray crystallography to gain insights into the binding mode of the corresponding heterocyclic phosphine oxide ("guest") and the resolving agent ("host") and to study the underlying phenomenon of enantiomeric recognition.

A new family of tartaric acid derived chiral iminophosphoranes has been developed as highly effective organocatalysts in the asymmetric chlorinations of 3-substituted oxindoles with a high level of enantioselectivity. Importantly, these catalysts are air- and moisture-stable. Recovery of the catalyst after simple chromatographic separation for reuse in the model reaction was achieved; the catalyst can be recycled six times without loss of any enantioselectivity. Several advantages of this catalytic process are high conversion after a very short reaction time at ambient temperature, low catalytic loading, and scale-up to multigram quantities with an excellent enantiomeric excess value of >99%, which meets the enantiomeric purity required for pharmaceutical purposes.

The regioselective conjugate addition of alkenylboronic acids to electronically-differentiated 1,4-enedicarbonyl compounds under metal-free conditions, using tartaric acid as promoter of the reaction is reported. The resulting compounds have been used as starting materials in the synthesis of 4-alkenyl-4,5-dihydropyridazin-3(2H)-ones or 4-alkylpyridazin-3(2H)-ones by reaction with hydrazine hydrate and acetic acid.

A tartaric acid derivative catalyzes the conjugate addition of diboron (III) to α,β-unsaturated ketones with moderate to good enantioselectivities.

The enantioselective alkenylation and arylation of tetrahydro-β-carbolines with boronates is presented using a metal free process in the presence of tartaric acid derivative as organocatalyst and DDQ as the oxidant.

A novel [4 + 2] cycloaddition to synthesize the title compounds bearing two chiral centers with high enantio- and diastereoselectivity is developed using the coupling reaction of isochromene acetals (I) with alkenyl boronates.

A new protocol for the intermolecular direct anti-carboboration by using tartaric acid as promoter and boronic acids as reactants is presented.

Upon several constructed bisphosphine ligands, BPL shows highest activity in the asymmetric O-allylation and moderate enantiomeric excesses are obtained.

The enantiospecific total synthesis of 14-membered macrolactone Sch 725674 was accomplished from tartaric acid. Key reactions in the synthesis include the Ley's dithiaketalization of an alkynone derived from the bis-Weinreb amide of tartaric acid, Boord olefination, and ring-closing metathesis of an acrylate ester.

An enantiospecific total synthesis of polyhydroxy δ-pyrone natural product (+)-anamarine is accomplished. The main features of the synthesis include the stereoselective reduction of the ketone obtained by the desymmetrization of the bis-dimethyl amide of tartaric acid and further elaboration involving asymmetric Brown's allylation and ring closing metathesis.

ingredients 11 of 100 g of pulp of tamarind fruit contain water (15-30%), protein (2-9%), fat (0.5-3%), total carbohydrate (56-82%), edible fiber (2.2-18.3%), ash (2.1-3.3%), calcium (81-466 mg), phosphorous (86-190mg), iron (1.3-10.9 mg), sodium (23-28 mg), potassium (62-570 mg). It also contains 41-58% sugars of which 25-45% is in the form of reducing sugars and 16% is in the form of non-reducing sugars and tartaric acid (8-18%) and ascorbic acid (3-9 mg). The composition of the tamarind fruit juice varies with geographical, cultural and seasonal harvesting and processing. An aqueous extract of tamarind fruit juice is acidic having pH 3.0 and acidity percentage is 50.3% and hence it will be work as an acid catalyst for condensation of carbonyl compounds and indoles. Therefore, we have used this fruit extract as natural catalyst for synthesis of bis-, tris-, and tetraindolyl compounds.

In conventional high-performance liquid chromatography, chiral separations are performed by chiral column with a chiral selector (CS) chemically boned to the solid support. In contrast, high-speed counter-current chromatography (HSCCC) performs chiral separations by dissolving CS in the liquid stationary phase. During the past two decades, several CSs were developed to successfully carry out chiral HSCCC which include N-dodecanoyl-L-proline-3,5-dimethylanilide, β-cyclodextrin derivatives, vancomycin, cinchona alkaloid derivatives, cellulose and amylose derivatives, tartaric acid derivatives, etc. Compared to HPLC which uses over hundred different kinds of CSs, the number of CSs effectively used in HSCCC is limited to several compounds. This may be due to the violent molecular movement of CS dissolved in the liquid stationary phase which reduces chiral selectivity based on steric affinity. Future development strategy of CS for HSCC proposed here is to suppress the molecular movement of the CS in the liquid stationary phase by the following three ways: 1) using viscous stationary phase such as aqueous-aqueous polymer phase system; 2) attaching a long hydrophobic chain to the asymmetric carbon, or 3) chemically bonding CS onto hydrophobic small particles such as carbon nanotubes, gold colloidal particles, and submicron silica particles.

An interesting formation of bis(5-arylfuran-2-yl)methanes is described involving TFA-mediated dimerization of enantiopure tartaric acid derived ketones (III) and (V).

In the presented study the synthesis of recyclable chiral ionic liquids from tartaric acid is described along with their application as chiral solvents in the Michael addition of malonates to chalcones.

Tartaric acid derived bidentate bisoxazoline ligands are applied as catalysts for the NFSI promoted enantioselective fluorination of β-keto esters (I).

A new class of highly stable O,N,N,O-tetradentate bioxazoline ligands were synthesized from l-tartaric acid. Exploration of those ligands in Pd-catalyzed asymmetric allylic alkylation yielded alkylated product up to 96% ee. Necessity of additional chelation to obtain high enantioselectivity was also demonstrated. Structural modifications of this ligand might result in identification of a novel privileged chiral ligand from an inexpensive chiral pool.

A novel library of chiral guanidines featuring a tartaric acid skeleton was developed from diethyl l-tartrate. These guanidines are easily accessed with tunable steric and electronic properties. The utilities of the guanidines were highlighted by their ability to catalyze the α-hydroxylation of β-ketoesters and β-diketones with remarkable efficiency and excellent enantioselectivity.

Tartaric acid is one of the most prominent naturally occurring chiral compounds. Whereas its application in the production of chiral ligands for metal-catalysed reactions has been exhaustively investigated, its potential to provide new organocatalysts has been less extensively explored. Nevertheless, some impressive results, such as the use of TADDOLs as chiral H-bonding catalysts or of tartrate-derived asymmetric quaternary ammonium salt catalysts, have been reported over the last decade. The goal of this article is to provide a representative overview of the potential and the limitations of tartaric acid or TADDOLs in the creation of new organocatalysts and to highlight some of the most spectacular applications of these catalysts, as well as to summarize case studies in which other classes of chiral backbones were better suited.

A convenient and efficient process for the synthesis of racemic trans-cyclohexanediamine (V) and its kinetic resolution using tartaric acid is described.

Molecular modelling of an iodine(III) phenoxide was used as a starting point in the design of chiral aryl iodide catalysts for stereoselective oxidative dearomatization reactions. Using this approach, catalysts derived from 8-iodotetralone and tartaric acid were constructed and used to synthesize enantioenriched para-quinols from phenols.

The photocatalyst BiFeO3 and multiferroic Co substituted BiFeO3 (BiFe0.95Co0.05O3) perovskite are synthesized by a tartaric acid modified sol—gel method involving Bi(NO3)3, Fe(NO3)3, and Co(NO3)2 hydrates in stoichiometric proportions.

Novel C 2-symmetric chiral bioxazolines were synthesized in good yields by the fusion of optically active acids with a tartaric acid derivative. Complexes of these products with copper(II) acetate monohydrate were found to be excellent catalysts for the Henry reaction, giving various nitro alcohols in very good yields and up to 84% enantiomeric excess. Although only five-membered chelation is possible with these ligands, they give better enantioselectivities than other bioxazoline ligands that undergo similar coordination.

Bi1.04-xYxFeO3 (0 ≤ x ≤ 0.30) ceramics are synthesized by a tartaric acid modified sol—gel method starting with aqueous solutions of Bi(NO3)3, Fe(NO3)3, Y(NO3)3, and tartaric acid (sintering at 600 °C for 2 h and 700 °C for 30 min).

12 α-Aminophosphonates of type (IV) are prepared in a one-pot three-component reaction using tartaric acid as catalyst, which provides easier work-up, affords better yields and takes less reaction time in comparison to generally used Lewis acid catalysts.

A novel spirocyclic TADDOL-derived quaternary ammonium salt is successfully applied as organocatalyst in the asymmetric α-alkylation of glycine Schiff base (I).

The asymmetric reduction of β-keto esters to their corresponding hydroxy alcohols can be performed by employing homogeneous and heterogeneous chemo- and bio-catalysis. This review covers the scope and limitations of different catalysts and methodologies that were employed for the reaction and compare between them on the basis of catalytic performance, product separation and catalyst recycling procedure. In general, heterogeneous catalytic systems are advantageous from industrial point of views as they can be easily separated by filtration and re-used. Nickel modified with tartaric acid and sodium bromide was found to be suitable heterogeneous catalyst for the enantioselective hydrogenation, yet its performance is lower than this of homogeneous chiral metal catalysts such as Ru-BINAP. Heterogenization of the chiral complex via immobilization or entrapment using organic and inorganic supports was thus tested. However, though the resulted heterogeneous analogues were highly enantioselective and could be re-used, the activity of the system is often very low compared to homogeneous system due to mass transfer limitations. Alternatively, performing liquid phase hydrogenation under homogeneous conditions, using Ru-BINAP soluble derivatives, yielded high activity and enantioselectivity. Product separation and catalysts recycling were facilitated by either extraction of the product with solvent that does not dissolve the complex or by selective filtration of the product. Alternatively, precipitation of the complex at the end of the reaction was also reported

Tartaric acid catalyzes the asymmetric addition of vinylboronates to N-acyl quinoliniums, affording highly enantioenriched dihydroquinolines. The catalyst serves to activate the boronate through a ligand-exchange reaction and generates the N-acyl quinolinium in situ from the stable quinoline-derived N,O-acetal.

α,β-Unsaturated ketones, α,β-unsaturated esters, and simple olefins are easily transformed into vicinal haloamino products with excellent regio- and stereoselectivity using TosNH2/NBS as the nitrogen/halogen sources and (+)-tartaric acid as catalyst.

A novel environmentally benign method for the synthesis of title compounds (IV), (VII), and (IX) using low melting mixtures as reaction medium is described.

Use of tartaric acid mono-3,5-di(tert-butyl)benzoate as chiral organocatalyst furnishes the addition products (III) and (V) in moderate yields with good enantioselectivity.

In order to develop a practical method for the construction of chiral molecules, we have designed a novel chiral reaction system possessing multi-metal centers utilizing tartaric acid ester as a chiral auxiliary. Based on this concept, we have developed an asymmetric 1,3-dipolar cycloaddition reaction of azomethine imines, an asymmetric hetero Diels-Alder reaction of nitroso compounds, an asymmetric Diels-Alder reaction of o-quinodimethanes. Furthermore, an asymmetric nucleophilic addition of alkynylzinc reagents, prepared in situ from dialkylzinc and 1-alkynes, to nitrones was achieved with high level of stereocontrol. In the last case, the addition of methylzinc salt of a product-like racemic hydroxylamine was found to be effective for unprecedented enhancement of enantioselectivity. © 2010 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 10: 173–187; 2010: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.201000002

This review focuses on structural aspects of inclusion complexation between selected host molecules that contain - OH sensor groups appended to, or associated with, heterocyclic moieties, and both non-chiral and chiral guests. Among the host compounds discussed, those derived from tartaric acid feature prominently as they have been extensively explored, especially in the context of optical resolution of racemic guests. Of the various techniques employed in the study of the derived solid-state inclusion complexes, single crystal X-ray studies have contributed significantly to an understanding of the roles of hydrogen bonding, van der Waals, C-H···π and π-π interactions in complex stabilization. For the host molecules described, the literature surveyed accordingly provides many case studies that feature X-ray analysis as a primary tool for investigating the mechanistic aspects of inclusion phenomena such as optical resolution and enantioselective photoreactivity.

Vapor-phase dehydration of ethylene glycol over acidic catalysts such as η-Al 2 O 3 , SiO 2 MgO, H 3 PW 12 O 40 , P 2 O 5 /AI 2 O 3 , AIPO 4 , and K 2 S 2 O 7 /SiO 2 has been examined as a probe reaction for attempted conversion of tartaric acid into pyruvic acid. The reaction was carried out by a conventional fixed-bed flow apparatus at 200–400°C with a space velocity of 1000 or 3600 h −1 for 10 vol% ethylene glycol in feed. η-Al 2 O 3 gave 1,4-dioxane as a major detectable product at 200–250°C. The yield passed through a maximum (35%) at 280°C and then decreased with increasing temperature. Formation of the intramolecular dehydration product, acetaldehyde, was observed at above 250°C, showing a plateau of yield (55°-60%) at higher temperatures. The lack of balance was presumably due to formation of linear polymers. Similar behavior was also observed for H 3 PW 12 O 40 , but no dioxane was detected for SiO 2 MgO. Dioxane activity showed a shift to higher temperature for P 2 O 5 /Al 2 O 3 and AlPO 4 , and thus both dioxane and acetaldehyde were obtained in the same temperature region above 250°C. It is of interest to note that AlPO 4 prepared from sulfate showed high selectivity to acetaldehyde, while dioxane was the predominant product for AlPO 4 from nitrate. K 2 S 2 O 7 /SiO 2 was another favorable catalyst for the intramolecular dehydration of glycol similar to AlPO 4 from sulfate, and revealed excellent activity for conversion of ethyl tartrate into ethyl pyruvate through dehydrative decarboxylation (yield 60% at 300°C with SV 500 h −1 ).

A tartaric acid–NaBr-modified Raney nickel catalyst prepared from ultrasonicated Raney nickel showed excellent enantio-differentiating and hydrogenating activity in the hydrogenation of a series of 3-oxoalkanoate and 1,3-diketones.

Dialkyl trans-2-alkoxy-2-alkyl-1,3-dioxolan-4,5-dicarboxylates and the corresponding N,N,N,N-tetramethyl-4,5-diamides have been prepared respectively from dialkyl tartrates or tartaric acid diamides. They smoothly reacted with silylenolethers in the presence of Lewis acids to give enantiomerically enriched (up to 90% d.e.) monoprotected 1,3-diketones. A dramatic dependence of the stereochemical outcome from the configuration of the enolic double bond of 4 has been observed. The products can be stereoselectively reduced to give configurationally defined monoprotected 3-ketols.

A simple and efficient synthesis of chiral cyclic imides with C2 symmetry based on smooth cyclisation of amides 4a-c obtained from (2R,3R) tartaric acid, is described.

Reduction of β,δ-diketo esters derived from tartaric acid with HAl( i -Bu) 2 gave stereoselectively β-hydroxy-δ-keto esters which were reduced with NaBH 4 and Et 2 BOMe to β,δ- syn -dihydroxy esters. This strategy was successfully applied to the systhesis of t -butyl (3 R ,5 S )6-oxo-3,5-isopropylidenedioxyhexanoate starting from D-tartrate.

Aqueous solutions of CO2 containing tetramethylammonium chloride were photolysed with visible light in the presence of colloidal ZnS to yield tartaric acid, glyoxylic acid, oxalic acid, formic acid and formaldehyde.

A series of host molecules derived from tartaric acid have been synthesized in optically resolved and racemic forms. Apart from two endo hydroxyl functions and four bulky aromatic groups (TADDOL-type=α,α,α',α'-tetraphenyl-1,3-dioxolane-4,5-dimethanols), they have specific polar and apolar substituents of different size, in different number, and in different positions laterally attached to the molecular framework as the characteristic features

An efficient enantiospecific synthesis of D-erythro-sphingosine (1) via azidosphingosine (2) is described, the absolute stereochemistry being derived from D-tartaric acid.