- HETEROCYCLIC COMPOUNDS FOR THE CONTROL OF INVERTEBRATE PESTS
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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
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- Preparation method for emtricitabine isomer
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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.
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- Convenient access to 5-membered cyclic iminium ions: Evidence for a stepwise [4 + 2] cycloaddition mechanism
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In situ generation and reaction of novel 5-membered N-tosyl cyclic α,β-unsaturated iminium ions from readily prepared stable precursors is demonstrated. Formal iminium Diels-Alder cycloaddition proceeded in good yield via a stepwise rather than concerted cycloaddition process, confirmed through the isolation of a Mukaiyama-Michael type intermediate. Relative stereochemistry was determined upon subsequent intramolecular cyclisation under Lewis acid catalysis to afford formal endo 5,6-spirobicyclic adducts, as confirmed by crystallography. Further synthetic elaboration towards complex molecular scaffolds based on the dinoflagellate metabolite portimine, a potent apoptosis inducer, were also developed.
- Freeman, Jared L.,Brimble, Margaret A.,Furkert, Daniel P.
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p. 2705 - 2714
(2019/03/13)
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- Photocatalyzed ortho-Alkylation of Pyridine N-Oxides through Alkene Cleavage
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A photocatalyzed reaction of pyridine N-oxides with alkenes gives ortho-alkylated pyridines with cleavage of the carbon–carbon double bond. Benzyl and secondary alkyl groups are incorporated at the ortho position of pyridines in one pot.
- Zhou, Wang,Miura, Tomoya,Murakami, Masahiro
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supporting information
p. 5139 - 5142
(2018/05/30)
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- Aminoglycoside type derivative and preparing method and application thereof
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The invention provides an aminoglycoside type derivative and a preparing method and application thereof. The aminoglycoside type derivative is a novel aminoglycoside type derivative. According to thederivative, the C2' amino position and the C6' amino pos
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Paragraph 0072
(2018/05/30)
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- Diversity-oriented synthesis of cyclopropyl peptides from Ugi-derived dehydroalanines
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A three-step synthesis of cyclopropyl peptides is reported. The protocol involves a consecutive Ugi-4CR/elimination reaction to prepare dehydroalanines followed by a Corey-Chaykovsky cyclopropanation reaction. Peptide-like molecules that resemble some pharmacologically active compounds with a variety of substituents in the cyclopropane ring were prepared. When (2-ethoxy-2-oxoethyl) dimethyl sulfonium ylide was used the reaction exclusively gives the cis-diastereoisomer cyclopropanes in good yields from readily prepared starting materials. A collection of 26 highly substituted cyclopropyl peptides were obtained.
- Contreras-Cruz, David A.,Sánchez-Carmona, Miguel A.,Vengoechea-Gómez, Fabio A.,Pe?a-Ortíz, Daniel,Miranda, Luis D.
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p. 6146 - 6156
(2017/09/29)
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- Nucleophile-Mediated Ring Expansion of 5-Acyl-substituted 4-Mesyloxymethyl-1,2,3,4-tetrahydropyrimidin-2-ones in the Synthesis of 7-Membered Analogues of Biginelli Compounds and Related Heterocycles
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A general six-step approach to alkyl 2-oxo-2,3,6,7-tetrahydro-1H-1,3-diazepine-5-carboxylates and 5-acyl-2,3,6,7-tetrahydro-1H-1,3-diazepin-2-ones based on the nucleophile-mediated ring expansion reaction of 5-functionalized 4-mesyloxymethyl-1,2,3,4-tetrahydropyrimidin-2-ones has been developed. Synthesis of the latter involved nucleophilic substitution of tosyl group in readily available N-[(2-benzoyloxy-1-tosyl)ethyl]urea with sodium enolates of β-oxoesters or 1,3-diketones, followed by dehydration or heterocyclization-dehydration of resulting products, removal of benzoyl protection, and conversion of hydroxymethyl group into mesyloxymethyl group. Conformations of the obtained tetrahydro-1H-1,3-diazepin-2-ones in solid state and solutions were established using X-ray diffraction and NMR spectroscopy. A plausible mechanism of tetrahydropyrimidine ring expansion based on DFT calculation at B3LYP/6-31+G(d,p) level and NMR monitoring experiments was discussed. The ring contraction reaction of methoxy- or phenylthio-diazepinones under acidic conditions resulted in the corresponding 3-functionalized 1-carbamoyl-1H-pyrroles.
- Fesenko, Anastasia A.,Grigoriev, Mikhail S.,Shutalev, Anatoly D.
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p. 8085 - 8110
(2017/08/14)
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- Reactions of peroxide products of ozonolysis of allyl ethers/esters in the AcOH-CH2Cl2 system on treatment with semicarbazide hydrochloride
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Background: A one-pot method for the preparation of the corresponding alkoxy acetic acids by low-temperature ozonolysis of allyl ethers/esters followed by treatment with semicarbazide hydrochloride has been suggested. The reaction occurs via formation of acetoxyhydroperoxide, subsequent reduction of which depends on the process temperature and the nature of the starting substrate. Objective: The article is aimed at the development of one-pot method for obtaining practically important alkoxy acetic acids, because the ozonolytic cleavage of a ?=? double bond is the key step in full syntheses of many biologically active compounds. Methods: We used a low temperature ozonolysis of functionally substituted olefins in the system acetic acid-methylene dichloride followed by reduction of semicarbazide hydrochloride. To create a method we have used available allyl ethers/esters as starting materials. Results: We investigated reaction of the peroxide products of ozonolysis of monoallyl ethers, ester and diallyl ethers in an AcOH/CH2Cl2 mixture on treatment with semicarbazide hydrochloride at various temperatures. We have discovered that the selectivity of reduction of acetoxyhydroperoxide formed at the first stage depends both on the process temperature and on the nature of the starting substrate. A decrease in temperature favors acid hydrolysis and formation of a carboxylic acid. Conclusion: We have proposed a simple and highly efficient one-pot method for the preparation alkoxy acetic acids without isolation of intermediate peroxides.
- Raskil'dina, Gulnara Z.,Legostaeva, Yuliya V.,Garifullina, Liliya R.,Sultanova, Rimma M.,Ishmuratov, Gumer Y.,Zlotskii, Simon S.
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p. 652 - 656
(2017/01/13)
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- Synthesis, structure, and conformational analysis of nucleoside analogues comprising six-membered 1,3-oxathiane sugar rings
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We report on the synthesis, characterization, and conformational analysis of 1,3-oxathiane nucleosides of both pyrimidine and purine nucleobases. The novel nucleoside analogues were prepared from readily available starting materials as α/β anomeric mixtur
- Abou Assi, Hala,Martínez-Montero, Saúl,Dixit, Dilip M.,Chua, Zhijie,Bohle, D. Scott,Damha, Masad J.
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p. 1945 - 1953
(2015/03/18)
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- Synthetic studies on saframycin anibiotics: an improved synthesis of tricyclic lactam intermediate and construction of the core ring system of saframycin A
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An improved synthesis of the tricyclic lactam intermediate of saframycin antibiotics and the construction of the core ring system having a cyano group at C-21 position were presented.1 The stereochemistry of several key intermediates was determined by X-r
- Kimura, Shinya,Kawai, Shintaro,Azuma, Masayuki,Umehara, Yoshifumi,Koizumi, Yu-Ichi,Yokoya, Masashi,Saito, Naoki
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p. 327 - 343
(2015/03/04)
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- Synthesis of functionalized tetrahydro-1,3-diazepin-2-ones and 1-carbamoyl-1H-pyrroles via ring expansion and ring expansion/ring contraction of tetrahydropyrimidines
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A general approach to 6-phenylthio-substituted 2,3,4,5-tetrahydro-1H-1,3- diazepin-2-ones based on the ring expansion reaction of 1,2,3,4- tetrahydropyrimidin-2-ones under the action of nucleophiles has been developed. The first step of the synthesis was preparation of N-[(2-benzoyloxy-1-tosyl) ethyl]urea by three-component condensation of 2-benzoyloxyethanal, urea and p-toluenesulfinic acid. Nucleophilic substitution of the tosyl group in the obtained sulfone with sodium enolates of α-phenylthioketones followed by cyclization-dehydration, and debenzoylation gave 4-hydroxymethyl-5-phenylthio-1, 2,3,4-tetrahydropyrimidin-2-ones which were transformed into the 4-mesyloxymethyl-derivatives. Treatment of the latter with nucleophilic reagents, such as NaCN, sodium diethyl malonate, PhSNa, MeONa, NaBH4, sodium succinimide, or potassium phthalimide, afforded the target multi-functionalized diazepinones. The obtained 6-phenylthio-diazepinones and their 6-tosyl-substituted analogues were converted into 3-substituted 1-carbamoyl-1H-pyrroles under acidic conditions as a result of ring contraction. Effective one-pot synthesis of the latter from 4-mesyloxymethyl-pyrimidines was realized using a ring expansion/ring contraction sequence.
- Fesenko, Anastasia A.,Trafimova, Ludmila A.,Shutalev, Anatoly D.
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supporting information; experimental part
p. 447 - 462
(2012/01/14)
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- PROCESS FOR THE MANUFACTURE OF CIS(-)-LAMIVUDINE
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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.
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- METHOD FOR THE SYNTHESIS OF 4-ALKOXY-, 4-HYDROXY- AND 4-ARYLOXY-SUBSTITUTED TETRAHYDRO-FURO[3,4-B]FURAN-2(3H)-ONE COMPOUNDS
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The present invention relates to a method for the synthesis of enantiomerically and diastereomerically enriched 4-alkoxy-, 4-hydroxy- or 4-aryloxy- substituted tetrahydro-furo[3,4-b]furan-2(3H)-ones by aldol coupling of a suitable hydroxyl-protected hydro
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Page/Page column 21
(2009/04/25)
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- General approach to 6-tosyl-2,3,4,5-tetrahydro-1H-1,3-diazepin-2-ones via nucleophile-mediated ring expansion of tetrahydropyrimidines
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A general six-step approach to 6-tosyl-2,3,4,5-tetrahydro-1H-1,3-diazepin-2-ones has been developed. The key step involves a ring expansion reaction of 4-mesyloxymethyl- or 4-tosyloxymethyl-5-tosyl-1,2,3,4-tetrahydropyrimidin-2-one mediated by nucleophili
- Fesenko, Anastasia A.,Tullberg, Marcus L.,Shutalev, Anatoly D.
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experimental part
p. 2344 - 2350
(2009/07/18)
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- Expedient synthesis and solvent dependent oxidation behavior of a water-soluble IBX derivative
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IBX derivative 6, synthesized in two steps from 2-aminoterephthalic acid, 8, is soluble in both DMF and water. A variety of alcohols are oxidized using 6 in DMF with ease and selectivity identical to that of parent IBX. However, oxidations carried out in water and other aqueous solvent mixtures using 6 exhibit unique selectivities toward different substrates and provide products different from reactions carried out in DMF. A mechanistic rationale is provided for this solvent dependent behavior of 6.
- Kommreddy, Amitha,Bowsher, Michael S.,Gunna, Meena R.,Botha, Kirankumar,Vinod, Thottumkara K.
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p. 4378 - 4382
(2008/12/21)
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- Facile preparation of α-acyloxyacetaldehyde, a versatile intermediate in the synthesis of antiviral nucleosides
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This report describes a novel and simple method for the preparation of a versatile intermediate, α-acyloxyacetaldehyde and its acetals, and its application to the synthesis of 4-acetoxy-2-acyloxymethyl-1,3-oxathiolane, an important intermediate in the syn
- Du, Jinfa,Watanabe, Kyoichi A.
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p. 1925 - 1930
(2007/10/03)
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- Preparation of intermediates useful in the synthesis of antiviral nucleosides
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The present invention is an efficient process for the manufacture of α-acyloxyacetaldehyde, a key intermediate in the synthesis of 1,3-oxathiolane and 1,3-dioxolane nucleosides.
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- Synthesis and properties of glycolaldehyde di- and triphosphate
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Use of photolabile acetal protecting groups enables the synthesis of glycolaldehyde di- and triphosphate 4 and 5, which undergo enolisation at significantly lower pH values than glycolaldehyde phosphate 1. At pH > 10, 5 is converted to 1 and inorganic pyrophosphate.
- Lawrence,Sutherland
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p. 170 - 172
(2007/10/03)
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- 2-Substituted-4-substituted-1,3-dioxolanes and use thereof
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Nucleoside analogues containing a 1,3-dioxolane structure are suitable antiviral agents, particulary for the treatment of the HIV infections in mammals, especially humans. Examples of the nucleoside analogues include: cis-2-acetoxymethyl-4-(thymin-1′-yl)-1,3,-dioxolane, cis-2-hydroxymethyl-4-(thymin-1′-yl)-1,3-dioxolane, cis-2-benzoyloxymethyl-4-(cytosin-1′-yl)-1,3-dioxolane, and cis-2-hydroxymethyl-4-(cytosin-1′-yl)-1,3-dioxolane. These compounds can be in the form of their racemates or their separate enantiomers.
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- Substituted 1,3-oxathiolanes with antiviral properties
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This invention relates to single enantiomers of novel cis-substituted 1,3-oxathiolanes, of the formula (I): wherein; R1is hydrogen, and R2is cytosine or 5-fluorocytosine; and pharmaceutically acceptable salts and esters thereof. This invention also relates to pharmaceutical compositions containing them and to the use of these compounds as antiviral agents, particularly in combination therapy.
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- Enantioselective allyltitanations. Synthesis of optically active 1,2- diol units: Useful intermediates for the preparation of biologically active compounds
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1,2-Diol units were synthesized with excellent enantiomeric excess by using an enantioselective allyltitanation of α-alkoxy-substituted aldehydes.
- Cossy, Janine,Bouzbouz, Samir,Caille, Jean Claude
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p. 3859 - 3862
(2007/10/03)
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- Stereoselective total synthesis of the pseudopterolide kallolide A
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A total synthesis of the pseudopterolides, kallolide A (36) and kallolide A acetate (35), has been achieved. The racemic forms were prepared from the syn adduct 20 of furan 13 and stannane 17 (BF3·OEt2-promoted addition) via the 15-membered propargylic allylic ether 25. [2,3]Wittig ring contraction led to the cis, anti, cis product 26. Alcohol 26 was transformed to butenolide 34 with net retention of configuration by Pd(PPh3)4- catalyzed carbonylation of the mesylate 27 and ensuing AgNO3-catalyzed cyclization of the derived allenic acid 29. Solvolysis of the SEM ether (at C2) 34 in acetic acid or aqueous t-BuOH afforded racemic kallolide A acetate (35) and kallolide A (36), respectively, with inversion of stereochemistry by an S(N)1 process. Key elements of stereocontrol, including the steric outcome of the [2,3]Wittig ring contraction, the allenic ester isomerization, and the solvolysis reactions, were predicted from molecular mechanics calculations. The C8 and C2 epimers 45 and 46 of the cis, anti, cis kallolide A SEM ether precursor 34 were also prepared. The synthetic route originated from the anti adduct 19 of aldehyde 13 and the allylic chloride 16 and CuCl (cat), HSiCl3, and i-Pr2NEt. Adduct 19 was subjected to the same sequence as the syn counterpart 20 to produce the trans, anti, cis[2,3]Wittig ring contraction product 42. The derived alleonate 44 afforded a 1:1 mixture of butenolides 45 and 46 upon sequential treatment with TBAF and AgNO3. Finally, the natural enantiomer (+)-36 of kallolide A was synthesized from the enantioenriched syn adduct (+)-20, prepared by addition of allylic stannane 17 to aldehyde 13 promoted by a modified chiral acyloxyborane Lewis acid.
- Marshall, James A.,Liao, Junkai
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p. 5962 - 5970
(2007/10/03)
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- Asymmetric synthesis of optically active 1,3-oxathiolane nucleoside analogues
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A ready asymmetric synthesis of 3'-oxa-4'-thionucleosides has been accomplished in three main steps from benzoyloxyethanal. The synthesis is characterized by high overall yield and appreciable enantiomeric excesses. It represents a general synthetic scheme to prepare a wide range of heterosubstituted sulfur-containing nucleoside analogues.
- Caputo, Romualdo,Guaragna, Annalisa,Palumbo, Giovanni,Pedatella, Silvana
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p. 1739 - 1745
(2007/10/03)
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- A Cyclization Approach toward Five-Membered Heteroaromatic o-Quinodimethanes via Fused-3-Sulfolenes
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A general strategy involving the zincation of 4-bromo-3-chloro-2-sulfolene, in situ condensation with an α-heterosubstituted acetaldehyde, and subsequent cyclization reaction as the key steps toward the synthesis of furano- and thieno-3-sulfolenes is desc
- Chou, Ta-Shue,Tsai, Chung-Ying,Lee, Shwu-Jiuan
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p. 299 - 307
(2007/10/03)
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- Substituted 1,3-oxathiolanes and substituted 1,3-dithiolanes with antiviral properties
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This invention relates to novel substituted 1,3-oxathiolanes and substituted 1,3-dithiolanes or pharmaceutically acceptable salts and esters thereof, of the formula: STR1 wherein X is S, S=O, or SO2 ; Y is O, S, S=O, or SO2 ; R1
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- Synthesis, NMR spectroscopy study, and antimuscarinic activity of a series of 2-(acyloxymethyl)-1,3-dioxolanes
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A series of 19-dioxolane-based ligands, bearing hydroxymethyl or ester functionalities, was synthesized and tested as potential muscarinic antagonists. The compounds display moderate to low affinity for the three receptor subtypes M1-M3/s
- Malmusi, Luca,Mucci, Adele,Schenetti, Luisa,Gulini, Ugo,Marucci, Gabriella,Brasili, Livio
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p. 2071 - 2080
(2007/10/03)
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- Dioxolane nucleosides and their phosphonate derivatives: synthesis and hydrolytic stability
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Several new nucleoside (12-15) and nucleoside phosphonate (27-30) analogues derived from (+/-)-cis- and -trans-2-hydroxymethyl-4-methyl-1,3-dioxolane have been prepared and their configurations assigned by 1H NMR spectroscopy.First-order rate constants fo
- Efimtseva, Ekaterina V.,Mikhailov, Sergey N.,Mashkov, Sergey,Hankamaeki, Teemu,Oivanen, Mikko,Loennberg, Harri
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p. 1409 - 1416
(2007/10/02)
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- Substrate Properties of Dioxolane Analogs of 3'-Deoxythymidine 5'-Triphosphate in Reactions of DNA Synthesis Catalyzed by Various DNA Polymerases
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The substrate properties of 3'-deoxythymidine 5'-triphosphate analogs prepared on the basis of 2,4-disubstituted 1,3-dioxolanes were investigated in reactions of the DNA synthesis catalyzed by various DNA polymerases.The 4'-triphosphates of (+/-)-cis-4-hy
- Efimtseva, E. V.,Mikhailov, S. N.,Viktorova, L. S.,Rozovskaya, T. A.,Beabealashvilli, R. Sh.
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p. 675 - 683
(2007/10/03)
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- A short synthesis of (±)-oxetanocin
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The photoadduct 9b of 2-methylfuran and propionyloxyacetaldehyde was transformed in a one-pot reaction to 10d, which gave oxetanocin and its epimer 1α as described.
- Hambalek,Just
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p. 5445 - 5448
(2007/10/02)
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- A CONVENIENT SYNTHESIS OF PROTECTED α-HYDROXYACETALDEHYDES
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Starting from 2,3-O-isopropylideneglycerol (1), a general procedure for the preparation of protected α-hydroxyacetaldehydes has been developed.
- Shiao, Min-Jen,Yang, Chia-Yu,Lee, Shi-Hung,Wu, Teh-Chun
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p. 359 - 366
(2007/10/02)
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- A STUDY ON THE SYNTHESIS OF CARUMONAM STARTING FROM AN α-AMINO ACID
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As part of a study on the synthesis of carumonam (1), a method starting from an α-amino acid was investigated.Cycloaddition of the mixed anhydride, derived from carbobenzoxyglycine (7) and isopropyl chloroformate, with the chiral imine (11b), derived from
- Hashiguchi, Shohei,Maeda, Yoshiharu,Kishimoto, Shoji,Ochiai, Michihiko
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p. 2273 - 2283
(2007/10/02)
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