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While ortho-alkoxy aryl sulfoxides including various substituents were synthesized by Sharpless asymmetric oxidation reaction, we optimized the reaction conditions and screened better combination of starting materials to obtain high enantioselectivity. The result suggested new information that electron-withdrawing substituents on the aromatic ring have a strong influence upon enantioselectivity of the products. Also, several chiral ligands for Sharpless asymmetric oxidation reaction were evaluated to improve the enantioselectivity. High enantioselectivity of ortho-alkoxy aryl chiral sulfoxides have been achieved by Sharpless oxidation reaction using Ti(O-i-Pr)4 and diethyl tartrate under anhydrous condition. In particular, the enantioselctivity of products was influenced by electron-withdrawing substituents on the aromatic ring, such as nitro, ester and aldehyde groups.

Non-isocyanate poly (hydroxyurethanes)s (PHUs) are important green alternatives to conventional polyurethanes. This work focuses on the synthesis of novel PHUs with an amide backbone and the study of the properties of PHUs regarding their potential use as hot-melt adhesive. PHUs were synthesized by a solvent-free and catalyst-free method from bis(2,3-dihydroxypropyl)ether dicarbonate and 1,3-diaminopropane using various molar ratios of diethyl tartrate. The polymers were properly characterized by FT-IR, 1H NMR and 13C NMR spectroscopy and the TGA and DSC analyses were performed. Rheological and mechanical properties are also presented. The work of adhesion and mechanical properties were determined. PHUs with diethyl tartrate-based amide backbone revealed improved thermal stability over conventional PHUs. The addition of diethyl tartrate increased the hydrophobicity of coatings by increasing the water contact angle and decreasing the polar component of surface free energy of PHU coatings. Furthermore, the mechanical properties of PHUs with addition of diethyl tartrate were noticeably improved.

A library of 13 esters and methylated esters, including entirely new molecules, derived from renewable natural tartaric acid, have been synthesized, characterized, and used as plasticizers of polylactide (PLA). Differential scanning calorimetry (DSC) studies of the blends consisting of PLA and tartaric acid derivatives reveal that all esters obtained exhibit plasticizing properties; however, their miscibility with PLA and ability to modify the thermal transition is dependent significantly on the structure of the ester group. It was found that esters bearing short alkyl groups (methyl, ethyl, n-butyl) may act as primary plasticizers that allow blends of elastomeric properties to exist at ambient temperature. The hydrolytic and enzymatic stability of plasticizers has been studied using dimethyl and diethyl tartrate, and both materials can be classified as biodegradable.

We report an efficient and practical synthetic route to various properly-protected erythreo-β-OH-Asp compounds, which are key β-branched α-amino acid units in coralmycin A and other peptide natural products. Fmoc and cyclic ketal-protected erythreo-β-OH-Asp 7 is prepared from cheap chiral precursor l -diethyl tartrate in six steps without the need of column purification. The modified form of 7 serves as a versatile precursor to various β-alkoxyl analogs of erythreo-β-OH-Asp. In addition, we successfully performed a model study toward the total synthesis of coralmycin A, featuring a late stage installation of the side chain primary amide group of erythreo-β-OMe-Asn.

In this work the esterification of diethyl tartrate was studied. The research was focused on the enhancement of reversible reaction yield, which is accomplished by dewatering of the reaction mixture. The removal of water shifts the equilibrium towards the main product. Pervaporation was applied for this purpose, and results were compared to distillation. The advantages and limitations of both processes are discussed. The experimental part consists of dewatering of mixture after the reaction had reached the equilibrium, and was subsequently fed to the test rig equipped with a single zeolite membrane purchased from Pervatech B.V. Results show a significant conversion increase as a result of water removal by pervaporation. Compared to distillation no addition of organics is necessary to efficiently remove water above the azeotrope. Nevertheless, some limitations and issues which call for optimisation are pointed out. A simple numerical model is proposed to support design and sizing of the pervaporation system. Various modes of integrated system operation are also briefly discussed.

In view of structural diversity, (+) montagnetol, the major metabolite of the fruticose lichen, Roccella montagnei was synthesized along with three of its congeners by employing highly efficient protocols. (+) Montagnetol (2 R, 3S; 11) and (-) montagnetol (2S, 3R; 5) were synthesized in 7 and 9 steps, respectively, from L-ascorbic acid. The two new congeners 3 (2 R, 3R) and 6 (2S, 3S), which differ in configuration at C-2 and C-3 positions of the (+) montagnetol, were synthesized from (−) diethyl D-tartrate and (+) diethyl L-tartrate, respectively. The synthesized compounds were evaluated in vitro for antimicrobial activity against two Gram-positive (S. aureus and E. coli) and two Gram-negative (S. typhi and P. aeruginosa) bacteria and one fungal strain Candida albicans. Interestingly, the congener 3 showed promising anti-bacterial activity (MIC: 0.062 µg/ml) against P. aeruginosa, whereas the congener 6 displayed potent anti-fungal activity (MIC: 0.062 µg/ml) against C. Albicans.

The chiral vicinal diol was protected as 6-methylene-1,4-dioxepane to construct a cyclopentene ring by the C H insertion of alkylidene carbene. The removal of the protecting group was achieved in a few steps, affording the corresponding diol in a reasonable yield. Using these reactions, the known synthetic intermediate for (+)-trehazolin was synthesized from d -diethyl tartrate. In addition, a short route to the intermediate from a d -mannitol derivative was described.

A facile and stereoselective synthesis of vittarilide-A, having promising antioxidant property was accomplished in 12 linear synthetic steps with an overall yield of 6.34% using a chiral pool approach from naturally available diethyl tartrate. The key reactions employed were diastereoselective vinylation, Sharpless asymmetric dihydroxylation, (2,2,6,6-tetramethylpiperidin-1-yl)oxy radical (TEMPO), bis(acetoxy)iodo-benzene (BAIB) mediated tandem oxidation followed by lactonization and finally esterification under Yamaguchi conditions.

Propellanes and azapropellanes are attractive compounds for their unique structure and valuable applications but there are few synthetic studies for highly N-substituted azapropellanes. Several novel derivatives of 2,4,6,8,10-pentaaza[3.3.3]propellane, such as 3, 4, and 5 were successfully synthesized from readily available diethyl tartrate. Most of the synthetic steps were efficient. Their propellane structures were established by spectroscopic data and confirmed with single crystal X-ray analyses.

An efficient asymmetric desymmetrization of meso-epoxides with anilines catalysed by a series of simple and environmentally benign in situ generated Fe(III) complexes based on chiral tridentate ligands L1–L7 with achiral and chiral linkers (methylene, piperazine, R/S BINOL and diethyl tartrate) was carried out at rt. The in situ generated iron metal complex based on ligand L5a emerged as improved (low catalyst loading) catalyst for asymmetric desymmetrization of meso-epoxides with anilines giving high enantioselectivity (up to 99%) and high yield (95%) of enantiopure β-amino alcohols in 14 h. While excellent results for ARO of cyclic as well as aliphatic epoxides with anilines was achieved with in situ generated complex from the ligand L4h and Fe(III) chloride, the catalyst was recoverable and recyclable (five times) with retention of its performance.

This paper studies the influence of Double (L- diethyl tartrate) boric acid ester (compatibilizer B) on the compatibility between PPO and PA66. Through the mechanical properties, Molau experiment, scanning electron microscope and tem analysis test method, it is proved that Double (L- diethyl tartrate) boric acid ester can be used as a new reactive compatibilizer in PPO/PA66 plastic alloy.

Organohalogen flame retardants, particularly brominated aromatics, are popular, effective, low cost, and widely used in the plastics industry. However, an increasing concern about persistence in the environment and potential negative health effects of these materials has generated intense interest in the development of alternatives. Ideally, these should have all the positive attributes of the materials that will be replaced. In addition, it is desirable that the new materials be as “green” as possible, e.g., based on renewable resources and be degradable to nontoxic products in the environment. A series of new, non-halogenated flame retardants based on tartaric acid is being developed. Tartaric acid is a by-product of the wine industry and is readily available locally on an annual basis (Michigan is the thirteenth largest producer of wine in the U.S.). It can be readily converted to the corresponding diethyl ester. This ester may serve as the base for the development of a series of new, non-halogenated flame-retarding agents. The presence of the reactive hydroxyl groups allows the introduction of a variety of phosphorus-containing moieties. For example, treatment of diethyl tartrate with diphenylphosphinyl chloride generates diethyl 2,3-di(diphenylphosphinato)-1,4-butanedioate. This material may serve as a monomer for the preparation of various phosphorus-containing polymers and oligomers via step-growth transesterification. The thermal stability of this compound has been assessed by thermogravimetry.

Numerous combinations of one-, two-, and three-chiral-component microemulsions have been previously prepared in our group, using N-dodecoxycarbonylvaline (DDCV), 2-hexanol, and ethyl acetate, dibutyl tartrate, or diethyl tartrate. A few results of the various formulations investigated suggested the possible presence of minor impurities in one or more components of the microemulsion. In this study, the purity of the current lots of R- and S-surfactant were measured, as was the subsequent effect of minor impurities on the relevant chromatographic figures of merit (CFOMs) that describe a chiral separation, i.e., efficiency, enantioselectivity, retention, migration window (elution range), and resolution. Two related methods are proposed for correcting enantioselectivities measured in the presence of chiral impurities in the chiral microemulsion.

Photoirradiation of 1-cyano-2-(5-methyl-2-oxa-4-hexenyl)naphthalene, included in NaY zeolites along with chiral inductors, such as diethyl tartrate or phenylalaninol, gives an intramolecular [2+2] photocycloadduct with a maximum 15% ee. The degree of enantioselectivity was found to depend on the Si/Al ratio, the nature of the cations in the zeolites, the structure of the chiral inductors, and the molar ratio of substrate and chiral inductors.

The aim of this study was to develop a drug eluting stent that prevents vein restenosis. For this, we selected argatroban as the study drug and poly(lactic acid) (PLA) as the matrix. To enhance the release of argatroban from PLA film, the addition of hydroxylesters (additives) was investigated. The additives investigated were diethyl tartrate (DET), diethyl malate (DEM), and triethyl citrate (TEC). Marked enhancement of drug release was observed in DET-added film, while TEC- or DEM-added film showed little enhancement. To clarify the effect of DET, the release profile based on the contents of the drug and DET in the film and the effect of alkyl chain length of tartrate were studied. Tartrates used were dimethyl, di-i-propyl, and di-n-butyl esters (DMT, DiPT, and DnBT, respectively), and the enhancement order was DMT ≅ DET ≫ DiPT ≅ DBT ≅ PLA alone. The reasons for enhancement were discussed from the viewpoint of drug release behavior, degradation of PLA, water uptake within the film, and SEM observations. It was concluded that enhancement of drug release was due to large amounts of water uptake within the film which resulted in the formation of open pores at its surface. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

An efficient asymmetric desymmetrization of meso-epoxides with anilines catalysed by a series of simple and environmentally benign in situ generated Fe(III) complexes based on chiral tridentate ligands L-1-L-7 with achiral and chiral linkers (methylene, piperazine, R/S BINOL and diethyl tartrate) was carried out at rt. The in situ generated iron metal complex based on ligand L(5)a emerged as improved (low catalyst loading) catalyst for asymmetric desymmetrization of meso-epoxides with anilines giving high enantioselectivity (up to 99%) and high yield (95%) of enantiopure beta-amino alcohols in 14 h. While excellent results for ARO of cyclic as well as aliphatic epoxides with anilines was achieved with in situ generated complex from the ligand L(4)h and Fe(III) chloride, the catalyst was recoverable and recyclable (five times) with retention of its performance

Novel microemulsion formulations containing all chiral components are described for the enantioseparation of six pairs of pharmaceutical enantiomers (atenolol, ephedrine, metoprolol, N-methyl ephedrine, pseudoephedrine, and synephrine). The chiral surfactant dodecoxycarbonylvaline (DDCV, R- and S-), the chiral cosurfactant S-2-hexanol, and the chiral oil diethyl tartrate (R- and S-) were combined to create four different chiral microemulsions, three of which were stable. Results obtained for enantioselectivity, efficiency, and resolution were compared for the triple-chirality systems and the single-chirality system that contained chiral surfactant only. Improvements in enantioselectivity and resolution were achieved by simultaneously incorporating three chiral components into the aggregate. The one-chiral-component microemulsion provided better efficiencies. Enantioselective synergies were identified for the three-chiral-component nanodroplets using a thermodynamic model. Additionally, two types of dual-chirality systems, chiral surfactant/chiral cosurfactant and chiral surfactant/chiral oil, were examined in terms of chromatographic figures of merit, with the former providing much better resolution. The two varieties of two-chiral-component microemulsions gave similar values for enantioselectivity and efficiency. Lastly, the microemulsion formulations were divided into categories based on the number of chiral microemulsion reagents and the average results for each pair of enantiomers were analyzed for trends. In general, enantioselectivity and resolution were enhanced while efficiency was decreased as more chiral components were used to create the pseudostationary phase (PSP).

A convenient route to enantiopure azetidine-2,3-diones is described. The chiral ketene generated from commercially available L-(+)-diethyl tartrate on Staudinger cycloaddition with different imines gave spiro-P-lactams in good yields. These spiro-p-lactams were transformed into azetidine-2,3-diones in excellent yields in a two-step process.

Invited for this month’s cover is the group of Dr. Sayed H. R. Abdi from Central Salt and Marine Chemicals Research Institute (CSMCRI), India. The cover picture shows a single metal complex that can catalyse the asymmetric epoxidation of non-functionalised olefins as well as oxidative kinetic resolution of racemic alcohols, which is carried out with great ease. Read the full text of the article at 10.1002/cplu.201402131

Bis(sodium sulfate) surfactants each bearing two alkyl groups were easily prepared by the acid-catalyzed transesterification of diethyl tartrate with fatty alcohols (octyl, decyl, or dodecyl) and subsequent sulfation with sulfamic acid without any expensive reagents and special equipment. These surfactants had better water-solubility, smaller critical micelle concentration (cmc) and lower surface tension at cmc compared to sodium dodecylsulfate and sodium tetradecylsulfate. These surfactants bearing octyl or decyl chains had low-foaming properties and good solubility in hard water. They decomposed easily into nonsurface-active species under acidic or alkaline conditions. Their biodegradabilities were almost the same as that of sodium dodecanoate.

In the present study, a less known polyester based on tartaric acid was characterized with respect to its degradation mechanism. Poly(2,3-(1,4-diethyl tartrate)-co-2,3-isopropyliden tartrate) (PTA) differs from commonly used biodegradable polyesters, such as poly(lactides-co-glycolides) (PLGA) by the presence of additional cleavable bonds in the polymer side chains. This modification results in different polymer properties and influences polymer degradation. The hydrolytic degradation of PTA was studied in parallel to PLGA using disc-shape matrices, which were obtained by compression-molding. The discs were incubated in pH 7.4 phosphate buffer solution at 37 degrees C. The degraded samples were characterized for percentage mass loss, water absorption, decay of molecular weight and change in glass transition temperature. The results demonstrate that the degradation of PTA proceeds via bulk erosion similar to PLGA. However, the degradation of PTA implants is characterized by a rapid mass loss within a short period of time appearing after a definite lag phase without remarkable mass loss. This makes the polymer promising for pulsatile drug release systems.

A Ti(O i Pr) 4 /diethyl tartrate/ t BuOOH complex oxidizes 3-hydroxyethyl-1,2-cyclopentanediones, resulting in hydroxylated/ring cleavage products—lactone acids of high enantioselectivity (up to 95% ee) with good yields (up to 75%). These compounds are converted into chiral spiro-γ-dilactones in good yield.

Ti(O i Pr) 4 /diethyl tartrate/ t BuOOH system oxidizes 3-alkyl-1,2-cyclopentanediones resulting in hydroxylated ring cleavage products 2-alkyl-γ-lactone acids, in high enantioselectivity (∼95% ee) and satisfactory isolated yields (up to 55%).

A new and highly selective method for the synthesis of hydroxyl-substituted tetrahydropyrans is described. This method utilizes titanium(IV) isopropoxide and diethyl tartrate to perform a diastereoselective epoxidation followed by in situ epoxide activation and highly selective endo-cyclization to form the desired tetrahydropyran ring. The HIJ ring fragment of the marine ladder polyether yessotoxin was synthesized using this two-stage tactic that proceeds with high efficiency and excellent regioselectivity.

A novel synthetic approach has been devoleped to incorporate donor-acceptor substituted π-conjugated segments and chiral centres in main-chain polymeric systems. A series of optically active main-chain polyesters were synthesized by high-temperature polycondensation from biphenolic azo chromophores, (2R,3R)-(+)-diethyl tartrate, and terephthaloyl chloride. The biphenolic chromophores were bis(4-hydroxyphenylazo)-2,2′-dinitrodiphenylmethane and bis(4-hydroxyphenylazo)-2,2′-dinitrodiphenylsulfone. The effects of solvent, reaction time, and temperature on the polymerization were investigated. The optical activity of the polymers showed that the introduction of a substantial amount of chiral groups in the polymer chain leads to the formation of non-centric configurations. The chiral order was found to be thermally stable. The polyesters showed glass transition temperatures in the range 100–190°C and were thermally stable up to 350°C. All polyesters showed positive solvatochromism in UV–visible absorption spectra.

2,3-Di(benzyloxy)buta-1,3-diene [403670-55-3] C18H18O2 (MW 266.33) InChI = 1S/C18H18O2/c1-15(19-13-17-9-5-3-6-10-17)16(2)20-14-18-11-7-4-8-12-18/h3-12H,1-2,13-14H2 InChIKey = WLRQWEQYYMRRBB-UHFFFAOYSA-N (reagent for the protection of vicinal diols and for use as Diels–Alder diene) Physical Data: white solid; mp 96 °C. Solubility: soluble in THF and DCM. Preparative Methods: prepared from diethyl tartrate in four steps.1 Diethyl tartrate was benzylated with NaH and BnBr in THF, followed by reduction of the esters with LiAlH4 to give 2,3-di-O-benzylerythritol. Subsequent conversion of both hydroxyl groups to the tosylates with TsCl in pyridine followed by elimination with t-BuOK in THF gave the 2,3-di(benzyloxy)buta-1,3-diene.

Catalytic properties of Ti-pillared montmorillonite for the epoxidation of (E)-hex-2-en-1-ol allylic alcohol. The present work is relative to the epoxidation of allylic alcohols by a well-characterised Ti-pillared montmorillonite (Ti-PILC) prepared by intercalating polymeric Ti cations formed by partial hydrolysis of TiCl 4 with HCl. The interlayer distance, the specific surface area and thermal stabilities of the resulting pillared clays depend mainly on the pH of the pillaring solution. For a ratio H + /Ti = 0.24, the Ti-PILC shows a basal spacing of 2,6 nm and a specific surface area of 316 m 2 ·g –1 , stable up to 773 K. In the conversion of isopropanol, this Ti-PILC shows a Lewis type acidity and a low redox activity. It catalyses the oxidation of allylic alcohol (E)-hex-2-en-1-ol with tert -butyl hydroperoxide in the presence of diethyl tartrate. The yield and nature of the final products depend on the reaction temperature and catalyst activation: no epoxidation could be obtained with non calcined samples. With a solid calcined in air at 773 K and then converted to a Ti-PILC, the main product is hexenoic acid for a reaction below 273 K, while the epoxide of the allylic alcohol is formed with 50 % yield at 298 K. This yield is comparable to that reported for the same substrate for polymer supported Ti(IV) catalysts.

Nonlinearity in the diastereoselectivity of epoxidation of allylic alcohols with mixtures of titanium isopropoxide, tertbutyl hydroperoxide, and diethyl tartrate was observed. Racemic and enantiomerically pure alcohols E-2-methyl-4-hexen-3-ol and E-1-methoxy-5-(O-tertbutyldimethylsilyloxy)-2-penten-4-ol were prepared. Epoxidation reactions were carried out with Ti(OPri)4 and ButOOH accompanied by diethyl tartrate of varying enantiomeric purity. The simplest explanation of these results is that a dimeric epoxidation reagent is involved, with significantly different reactivity for the homochiral and racemic forms. Chirality 12:496–504, 2000. © 2000 Wiley-Liss, Inc.

Aliphatic polyamides of interest as macromolecular drug carriers are synthesized by base-catalyzed polycondensation of aliphatic diesters with diamines. The reactions are conducted in the presence of anhydrous sodium carbonate at temperatures ranging from ambient to 65°C, initially in the undilute state. The addition of aprotic solvent at a later stage serves to maintain sufficiently low viscosity for proper homogenization. The comonomers, diethyl 3,6,9-trioxaundecanedioate and 4,7,10-trioxa-1,13-tridecanediamine, copolymerize to form polymer 1, a straight-chain polyamide devoid of specific functionality. Use of diethyl tartrate in lieu of the aforementioned diester leads to polyamide 2 possessing hydroxyl side groups. Other experiments in which diamines incorporating additional (secondary) amino groups are employed afford polyamides 3–8 containing such secondary amine functions as main-chain constituents. The water-soluble target polymers are crudely fractionated by aqueous dialysis (12000–14000 molecular mass cut-off) and collected by freeze-drying in yields of 20 to 40%. The low-yield range has been accepted in this investigation as the price to be paid for the realization of linear polyamide structures in accordance with compositional expectations, a requirement vital for the proper functioning of the polymers as drug carriers. The practicability of drug binding (conjugating) is exemplified by the coupling of ferrocene as a drug model to polyamide 5 via amide linkage. The water-soluble conjugate 5-Fc features an iron content corresponding to one ferrocene group in the repeat unit. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 2143–2150, 1999

Chiral building blocks derived from l -diethyl tartrate are derivatized into various chiral arachidonic acid analogs based on a dioxane core.

A synthetic strategy for an enantiomeric pair of FR900482 (1) was developed, which features a convergent and enantioselective sequence starting from 5-hydroxyisophthalic acid (16) and each enantiomer of diethyl tartrate (17 and ent-17). The proposed key intermediate 10 was synthesized from FK973 (3), the triacetyl derivative of 1, and successful reconversion of 10 into 1 was also achieved. These preliminary studies definitely demonstrated that 10 is suitable as a potential advanced key intermediate for 1 and that the crucial final sequence of reactions ( 10→1 ) involving delicate deprotection and oxidation steps can be realized.

Synthesis of glucosidase inhibitors, DAB-1 (1) and LAB-1 (2) from diethyl tartrate is described. The procedure afforded an epimerizable mixture of diastereomeric intermediates 8 and ent. 8, and opened the door not only to the selective synthesis of DAB-1 and LAB-1 but for giving various related analogs.

Nectrisine 1 , a potent glycosidase inhibitor, and 4-epi-Nectrisine 2 were synthesized from D-(−)- diethyl tartrate through the corresponding lactams. N-acyl protection was crucial to effect the reduction of the corresponding lactams to amino alcohols

This account describes our first total synthesis of an enantiomeric pair of FR900482 (1 and ent-1), which was accomplished in a convergent manner utilizing the aromatic segment 14 and the aliphatic segment 15 and ent-15 accessible from commercially available 5-hydroxyisophthalic acid (16) and each enantiomer of diethyl tartrate (17 and ent-17), respectively. The method for the total synthesis involves the following four key steps : (i) coupling reaction of 14 with 15 (14+15→32, Scheme 5); (ii) intramolecular aldol reaction of the highly functionalized dialdehyde 13 (13→36, Scheme 6); (iii) epimerization at the C-8 position of the hydroxy ketone 40 (40→41, Scheme 7); (iv) internal hemiacetal formation of the N-hydroxylamino ketone 11 in situ generated from the ketone 45 (45→11→10, Scheme 10). The in vitro cytotoxicity assay of the synthesized compounds (1, ent-1, 50, ent-50, 51, and ent-51) against P388 murine leukemia cells disclosed that 1 and its congeners 50, 51 possessing natural absolute configuration are ca. 100 times more cytotoxic than the corresponding unnatural enantiomers (ent-1, ent-50, ent-51).

The synthesis of the aromatic fragment 4 was achieved starting from commercially available 5-hydroxy-isophthalic acid (6) by utilizing Claisen rearrangement of 9, bromolactonization of 12, and modified Curtius rearrangement of 16 as key steps. Furthermore, the optically active aliphatic fragment 5 was synthesized in an optically pure form starting with l -diethyl tartrate (7) by featuring epoxide formation of 26, nucleophilic epoxide opening of 27 with an azide anion, reduction of the azide function in 33 to an amine, and formation of the N-protected 1,3-oxazolidine 35.

Oxidation of methylthio substituted tricarbonyl(η 6 -arene)cbromium(0) complexes with Ti(OPr i ) 4 / diethyl tartrate / H 2 O / cumene hydroperoxide (2:4:2:1.3) gives methylsulfinyl substituted tricarbonyl(η 6 -arene)chromium(0) complexes in 60–73% yield and 81–86% e.e. (29–60% yield and 90-≥95% e.e. after crystallisation); diethyl tartrate gives higher optical and chemical yields than dimethyl or diisopropyl tartrates and the reaction conditions are ineffective for other alkylthio and arylthio substituents; diethyl l -(+)-tartrate and diethyl d -(−)-tartrate lead to complexes of R and S configuration respectively; although an attempted kinetic resolution of tricarbonyl[η 6 -(methylsulfinyl)benzene]chromium(0) was unsuccessful, subjecting tricarbonyl[η 6 -1-methyl-2-(methylthio)benzene]chromium(0) to kinetic resolution conditions led to the isolation of recovered starting material and the corresponding sulfinyl substituted complex with enantiomeric excesses of 59 and 60% respectively.

Oxidation of sulfenyl substituted tricarbonyl(η 6 -arene)chromium(0) complexes with Ti(OPr i ) 4 / diethyl tartrate / H 2 O / cumene hydroperoxide (2:4:2:1.3) gives sulfinyl substituted tricarbonyl(η 6 -arene)chromium(0) complexes in 60–73% yield and 81–86% e.e. (29–60% yield and 90-≥95% e.e. after crystallisation); diethyl L-(+)-tartrate was shown to lead to complexes of R configuration.