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Compounds of formula (I) wherein Het1, Het2, R1, R2 and R3 are as defined in the description. Medicaments.

The invention relates to compounds of formula (I) wherein the variables have the meanings as defined in the specification, to compositions comprising them, to active compound combinations comprising them, and to their use for protecting growing plants and

An emerging biogenic aprotic solvent is the cellulose-derived dihydrolevoglucosenone, or 6,8-dioxabicyclooctanone (Cyrene). This paper explores the use of Cyrene in lipase-catalyzed biotransformations, both in aqueous solutions – as co-solvent – as well a

Mincle, expressed in activated phagocytes, recognizes the lipid ligand to activate the innate immune system. We have synthesized glycerol derivatives possessing simple alkyl chains or aromatic rings and elucidated their structure-activity relationships us

The invention discloses a preparation method for an embritabine isomer. The preparation method comprises the following steps: with Solketal as a starting material, allowing the Solketal to undergo a six-step reaction of esterification, hydrolysis, oxidation, condensation cyclization, acetylation and glycosylation condensation so as to synthesize four mixture intermediates of emtricitabine; and splitting the four isomer intermediates into a cis-isomer mixture and a trans-isomer mixture through a chiral reagent. According to the invention, by adoption of a simple starting material, a mixture forsplitting key intermediates of four optical isomers of the emtricitabine is synthesized through the six-step reaction, and chiral acid is utilized to split the four isomers into a mixture of cis andtrans isomers, so the preparation method provided by the invention has the advantages of simple and convenient operation, high yield and high isomer chiral purity.

The invention discloses an industrial preparation method of 2,2-dimethyl-4-hydroxymethyl-1,3-dioxolane. The industrial preparation method of the 2,2-dimethyl-4-hydroxymethyl-1,3-dioxolane comprises the steps that (1) carboxylic acid monoglyceride is prepared by esterification reaction, specifically, glycerol and carboxylic acid are used as raw materials, and under the condition of acidic catalyst,the dehydration reaction is carried out under the condition of 90-150 DEG C for 0.5-4h to obtain the carboxylic acid monoglyceride; (2) ketal cyclization reaction is carried out, specifically, the carboxylic acid monoglyceride and acetone are controlled to perform the cyclization reaction at 20-50 DEG C for 0.5-3 h under the condition of acid catalyst reaction to obtain a cyclization intermediateproduct; and (3) hydrolysis reaction is carried out, specifically, the intermediate product obtained in the step (2) is added into an alkaline solution, the mixture reacts for 0.5-1 h at 20-50 DEG C,and the 2,2-dimethyl-4-hydroxymethyl-1,3-dioxolane is obtained. The industrial preparation method of the 2,2-dimethyl-4-hydroxymethyl-1,3-dioxolane has the characteristics of green and environment-friendly process, high selectivity of industrial reaction and high conversion rate of raw materials.

Hexabromoacetone (HBA) was efficiently used for the protection of alcohols and aldehydes and deprotection of benzaldehyde dimethyl acetal, solketal, and other acetals and ketals. In only 10?min, the protection of glycerol yielded 90% of solketal and protection of benzaldehyde gave 95% of benzaldehyde dimethyl acetal. The deprotection of benzaldehyde dimethyl acetal under UV irradiation gave over 90% yield of benzaldehyde within 15?s using only 2.5?mol% of HBA. HBA was also successfully used for deoximation. Solvent was found to play an important role in the efficiency of HBA for these reactions.

Antibacterial compositions and methods for inhibiting bacterial growth are disclosed. The antibacterial compositions can include a carrier and an antibacterial agent including a benzoic acid ester. The benzoic acid ester can have a carbon chain having a length of two to ten. The benzoic acid ester can have a hydroxyl group on the carbon chain.

An inexpensive, green, metal-free one-pot procedure for the dihydroxylation of alkenes is described. H2O2 and 2,2,2-trifluoroacetophenone were employed as the oxidant and organocatalyst, respectively, in this highly sustainable protocol in which a variety of homoallylic alcohols, aminoalkenes, and simple alkenes were converted into the corresponding polyalcohols in good to excellent yields. This process takes advantage of an epoxidation reaction followed by an acidic treatment in which water participates in the ring opening of the in situ prepared epoxide to lead to the desired product.

An efficient method for regioselective benzoylation of diols and polyols was developed. The benzoylation is catalyzed by only 0.2 equiv of benzoate anion in acetonitrile with the addition of a stoichiometric amount of benzoic anhydride under very mild condition, leading to high yields. Compared with all other methods, this method shows particular advantage in regioselective multiple benzoylation of polyols, and in avoiding the use of any metal-based catalysts and any amine bases, which is more environment-friendly.

Background: Cytofectins are a class of positively charged lipid molecules that can facilitate the functional entry of polynucleotides, macromolecules, and small molecules into living cells, escaping lysosomal degradation. One of the most potent cytofectins, dimyristoyl Rosenthal inhibitor ether (DMRIE), is presently being used to deliver differents active molecules into animal and human diseased tissues. To our knowledge, two synthetic routes for the preparation of DMRIE have so far been reported. One of them is based on the reaction of epichlorhydrin with either dimethylamine chloride or dimethylamine using an alkaline solution as solvent. The main disadvantage of these routes is the formation of 3-(N,N-diamino)-1,2-propanediol. In summary, the synthetic routes mentioned use epichlorohydrin or glycidol as starting materials, both of which have been described as carcinogenic agents. Additionally, sometimes the reaction conditions are drastic. An alternative route for the preparation of other cytofectins is the use of glycerol as the starting material. Glycerol is a non-carcinogenic compound, but its use as starting material results in an increased number of steps of this reaction, generating an increase in the total time of synthesis and the formation of a greater amount of waste and scrap. Based on the above, here we propose a new chemoenzymatic synthetic strategy using glycerol as a starting material. Methods: Initially, glycerol and vinyl benzoate were mixed in presence of Mucor miehei lipase (Lipozyme), it is converted into corresponding mono-benzoate (±)-1. Finally, DMRIE was obtained by the reaction of bromide (±)-3 with 2- dimethylaminoethanol (DMAE). Results: We studied the stability of compound (±)-1 under the working conditions applied in the preparation of intermediate alcohol (±)-2. Additionally, we study different experimental parameters. Conclusion: In summary, a new chemoenzymatic synthetic route was developed for the DMRIE using glycerol as the starting material. We studied and optimized various experimental parameters of the various synthetic steps, and reached to develop the methodology to multigram scale, which compared to processes reported so far, has the advantages of fewer synthetic steps, the use of less aggressive reagents environment and generating fewer waste allowed to obtain the desired product; which results in a viable method for synthesizing analogs to DMRIE.

Background: Cytofectins are a class of positively charged lipid molecules that can facilitate the functional entry of polynucleotides, macromolecules, and small molecules into living cells, escaping lysosomal degradation. One of the most potent cytofectins, dimyristoyl Rosenthal inhibitor ether (DMRIE), is presently being used to deliver differents active molecules into animal and human diseased tissues. To our knowledge, two synthetic routes for the preparation of DMRIE have so far been reported. One of them is based on the reaction of epichlorhydrin with either dimethylamine chloride or dimethylamine using an alkaline solution as solvent. The main disadvantage of these routes is the formation of 3-(N,N-diamino)-1,2-propanediol. In summary, the synthetic routes mentioned use epichlorohydrin or glycidol as starting materials, both of which have been described as carcinogenic agents. Additionally, sometimes the reaction conditions are drastic. An alternative route for the preparation of other cytofectins is the use of glycerol as the starting material. Glycerol is a non-carcinogenic compound, but its use as starting material results in an increased number of steps of this reaction, generating an increase in the total time of synthesis and the formation of a greater amount of waste and scrap. Based on the above, here we propose a new chemoenzymatic synthetic strategy using glycerol as a starting material. Methods: Initially, glycerol and vinyl benzoate were mixed in presence of Mucor miehei lipase (Lipozyme), it is converted into corresponding mono-benzoate (±)-1. Finally, DMRIE was obtained by the reaction of bromide (±)-3 with 2-dimethylaminoethanol (DMAE). Results: We studied the stability of compound (±)-1 under the working conditions applied in the preparation of intermediate alcohol (±)-2. Additionally, we study different experimental parameters. Conclusion: In summary, a new chemoenzymatic synthetic route was developed for the DMRIE using glycerol as the starting material. We studied and optimized various experimental parameters of the various synthetic steps, and reached to develop the methodology to multigram scale, which compared to processes reported so far, has the advantages of fewer synthetic steps, the use of less aggressive reagents environment and generating fewer waste allowed to obtain the desired product; which results in a viable method for synthesizing analogs to DMRIE.

Oxidative esterification of benzylic alcohols with a catalytic amount of HBr-H2O2 in aqueous medium under mild conditions is reported with a wide range of substrate scope for both benzylic and aliphatic alcohols. The conditions are also suitable for selective mono-esterification of ethylene glycol and glycerol. With catalytic amounts of HBr (20 mol%) and H2O2, the generation of reactive intermediate species BrOH has been ascertained by UV-visible spectra.

A new catalyst derived from osmium has been prepared, fully characterized and tested in the dihydroxylation of alkenes. The catalyst was prepared by wet impregnation methodology of OsCl3·3H2O on a commercial micro-magnetite surface. The catalyst allowed the reaction with one of the lowest osmium loadings for a heterogeneous catalyst and was selective for the monodihydroxylation of 1,5-dienes. Moreover, the catalyst was easily removed from the reaction medium by the simple use of a magnet. The selectivity of catalyst is very high with conversions up to 99%. Preliminary kinetics studies showed a first-order reaction rate with respect to the catalyst.

A novel efficient and recyclable temperature-dependent biphasic catalyst and reaction media combined system comprised of PEG-1000 linked dicationic acidic ionic liquid and toluene was developed and applied in esterification of aromatic acids and acetalization of aromatic aldehydes with good to excellent yields. This system is characteristic of temperature-dependent reversible biphasic property, simple and facile recyclability, high catalytic activity and extensive substrate and reaction adaptability.

An improved process for the manufacture of Lamivudine. The process involves: (a) resolution of racemic lamivudine (intermediate of formula IX) to cis (±) lamivudine of formula (XII) by forming a crystalline salt and separating the product from an organic solvent by fractional crystallization; (b) resolution of cis (±) lamivudine to cis (?) isomer involving formation of S-Binol adduct of formula XIV.

Aerobic oxidation of aldehydes to 1,2- and 1,3-diol monoesters was catalyzed by polymer-incarcerated gold nanoclusters under ambient conditions. The esterification proceeded much faster with 1,2- and 1,3-diols and their derivatives rather than with methanol. Magnum PI: Gold-nanocluster catalysts, PI-Au, that were immobilized on polystyrene-based polymers with cross-linking moieties, were used to catalyze the syntheses of 1,2 and 1,3-diol monoesters and their derivatives from aldehydes. The effect of neighboring-group participation in the esterification reaction is also described. Copyright

Selective detritylation is quite crucial in synthetic chemistry. A mild and efficient procedure for selective hydrolysis of trityl ethers in the presence of other frequently used hydroxy protecting groups: TBDPS, Bz, Bn, Ac and Ts with antimony trichloride was described and 5′-trityl uridine was detritylated smoothly too. Copyright Taylor & Francis Group, LLC.

The synthesis and antiviral evaluation of new acyclic phosphonate nucleosides related to HPMPC (Cidofovir) has been described. These aminopropyl phosphonate nucleosides 1-3 have an amino function within either the acyclic chain (series 2 and 3) or as subs

Acyl or alkyl glycidols in the presence of trifluoroacetic anhydride (TFAA) and trifluoroacetate anions, undergo a regioselective and stereospecific opening of the oxirane system to produce the bis(trifluoroacetylated) derivatives, from which the corresponding 1(3)-monoacyl-sn-glycerols or 1(3)-monoalkyl-sn-glycerols can be obtained directly in high purity (>99%) and in quantitative yields.

The direct monoacylation of diols by acyl phosphate monoesters in water is a biomimetic analogy to the enzymic aminoacylation of tRNA by aminoacyl adenylates. Without catalysis, acyl phosphate monoesters react rapidly with amines but very slowly with water and alcohols. Lanthanide ions dramatically and selectively facilitate the base-catalyzed monoacylation of diols in water by methyl benzoyl phosphate (MBP), a typical acyl phosphate monoester, in neutral solutions where reactive amines are protonated and unreactive. The reaction patterns and reactivity of various diols with MBP in the presence of lanthanides are consistent with a mechanism that involves internal addition from the conjugate base of the bis-bidentate complex of the lanthanide with the diol and MBP. The method is also applicable to reactions of nucleosides as evidenced by the selective monoacylation of the 2′- or 3′-hydroxyl group of adenosine, without reaction of the 5′-hydroxyl group or the 6-amino group. Analogues of adenosine without the diol are unreactive. This suggests that the method will selectively monoacylate the hydroxyl groups at the unique diol in tRNA that forms the 3′-terminus.

Silicna gel-supported ceric ammonium nitrate (CAN-SiO2) was found effective for rapid and selective cleavage of trityl (Tr), monomethoxytrityl (MMTr), and dimethoxytrityl (DMTr) groups from protected nucleosides and nucleotides under mild conditions. Efficiency of deprotections depended upon the stability of th resultant carbocationic species: DMTr+ > MMTr+ > Tr+. Use of a catalytic amount of this solid-supported reagent can also efficiently and selectively remove the tert butyldimethylsilyl or the triisopropylsilyl group from a primary hydroxyl functionality in di- or trisilyl ethers of ribonucleosides. A comparative stud of deprotection reactions by utilization of CAN alone or CAN-SiO2 indicates a remarkable increase in the rate of the reactions involving a solid support. The mechanism of electron-transfer processes is proposed for the use of CAN-SiO2 in the removal of these protective groups from organic molecules.

The synthesis of α-monoglycerides of aromatic acids has been performed by the transesterification of the methyl esters of the corresponding acids with glycerol. The structures of the compounds obtained have been confirmed by their IR, UV, and 1H and 13C NMR spectra.

A variety of epoxides are efficiently hydrolysed to diols with water without using any catalysts under high pressure conditions.

In the presence of a catalytic amount of bis(3-methyl-2,4-pentanedionato)nickel(II) (Ni(mac)2), various glycidyl esters are converted into the corresponding glycerol monoester derivatives with molecular oxygen in good to high yields.

Starting from 2,3-O-isopropylideneglycerol (1), a general procedure for the preparation of protected α-hydroxyacetaldehydes has been developed.

Anodic oxidation of aldehyde acetals to esters under very mild conditions is achieved in a neutral solution by utilizing N-hydroxy-phthalimide as a mediator.The oxygen source of the oxidation is thought to be not dioxygen but water.Keywords: acetal; anodic oxidation; mediator; N-hydroxy-phthalimide; ester; glyceride.