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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.

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.

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

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

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.