64904-47-8Relevant academic research and scientific papers
HETEROCYCLIC COMPOUNDS FOR THE CONTROL OF INVERTEBRATE PESTS
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Page/Page column 29; 33; 40, (2021/11/20)
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
Preparation method for emtricitabine isomer
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, (2019/04/26)
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.
Convenient access to 5-membered cyclic iminium ions: Evidence for a stepwise [4 + 2] cycloaddition mechanism
Freeman, Jared L.,Brimble, Margaret A.,Furkert, Daniel P.
, p. 2705 - 2714 (2019/03/13)
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.
Photocatalyzed ortho-Alkylation of Pyridine N-Oxides through Alkene Cleavage
Zhou, Wang,Miura, Tomoya,Murakami, Masahiro
supporting information, p. 5139 - 5142 (2018/05/30)
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.
Aminoglycoside type derivative and preparing method and application thereof
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Paragraph 0072, (2018/05/30)
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
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
Fesenko, Anastasia A.,Grigoriev, Mikhail S.,Shutalev, Anatoly D.
, p. 8085 - 8110 (2017/08/14)
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.
Diversity-oriented synthesis of cyclopropyl peptides from Ugi-derived dehydroalanines
Contreras-Cruz, David A.,Sánchez-Carmona, Miguel A.,Vengoechea-Gómez, Fabio A.,Pe?a-Ortíz, Daniel,Miranda, Luis D.
supporting information, p. 6146 - 6156 (2017/09/29)
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.
Reactions of peroxide products of ozonolysis of allyl ethers/esters in the AcOH-CH2Cl2 system on treatment with semicarbazide hydrochloride
Raskil'dina, Gulnara Z.,Legostaeva, Yuliya V.,Garifullina, Liliya R.,Sultanova, Rimma M.,Ishmuratov, Gumer Y.,Zlotskii, Simon S.
, p. 652 - 656 (2017/01/13)
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.
Synthesis, structure, and conformational analysis of nucleoside analogues comprising six-membered 1,3-oxathiane sugar rings
Abou Assi, Hala,Martínez-Montero, Saúl,Dixit, Dilip M.,Chua, Zhijie,Bohle, D. Scott,Damha, Masad J.
, p. 1945 - 1953 (2015/03/18)
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
Synthetic studies on saframycin anibiotics: an improved synthesis of tricyclic lactam intermediate and construction of the core ring system of saframycin A
Kimura, Shinya,Kawai, Shintaro,Azuma, Masayuki,Umehara, Yoshifumi,Koizumi, Yu-Ichi,Yokoya, Masashi,Saito, Naoki
, p. 327 - 343 (2015/03/04)
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
