共查询到20条相似文献,搜索用时 15 毫秒
1.
Vishal A. Mahajan 《Tetrahedron letters》2005,46(6):1009-1012
A synthesis of novel 4-(substituted)benzyl-5-methylene-2(5H)-furanones involving Stobbe condensation of substituted aldehydes with ethyl levulinate followed by treatment with acetic anhydride in the presence of sodium acetate, has been developed. 相似文献
2.
Young Seob Song 《Tetrahedron letters》2006,47(42):7427-7430
The Suzuki-Miyaura coupling reactions of 3-bromo-2(5H)-furanones with a variety of arylboronic acids, promoted by microwave heating, efficiently generate 3-aryl-2(5H)-furanones. This remarkably rapid process serves as the foundation for a simple method to rapidly construct 3-aryl-2(5H)-furanone libraries. 相似文献
3.
George Iskander 《Tetrahedron letters》2009,50(32):4613-4615
A versatile method for the synthesis of novel brominated 4-alkyl-2(5H)-furanones under mild reaction conditions is described. This synthetic strategy requires only one chromatographic separation over six steps and employs the cyclodehydration of brominated levulinic acid as the key transformation. 相似文献
4.
DFP, a highly selective and potent COX-2 inhibitor, has been synthesized by a modified approach. Three modifications of the existing method enabled us to prepare DFP in good quantity. 相似文献
5.
4-(1-Alkynyl)-3-bromo- and 4-(1-alkynyl)-3-chloro-2(5H)-furanones have been regioselectively synthesized in moderate to good yields by a new version of the Pd/Cu-catalyzed Sonogashira reaction involving treatment of 1-alkynes with 3,4-dibromo- and 3,4-dichloro-2(5H)-furanone, respectively, in the presence of KF as a base. 4-(1-Alkynyl)-3-bromo-2(5H)-furanones have been found to be able to undergo Stille-type and Suzuki-type reactions with aryl(tributyl)tins and arylboronic acids, respectively, to give 4-(1-alkynyl)-3-aryl-2(5H)-furanones in modest to satisfactory yields. Some 4-(1-alkynyl)-substituted 2(5H)-furanones so prepared have been found to exhibit significant cytotoxic activities, especially against human leukemia cell lines. 相似文献
6.
The reactivity of 5-methyl-4-(pyrrolidin-1-yl)-5H-furan-2-one with aldehydes and with acyl chlorides followed by reduction was studied. The aldol condensation gave predominantly the anti aldol product when the acylation-reduction sequence led exclusively to the syn product. The use of a chiral pyrrolidine, (S)-2-methoxymethylpyrrolidine (SMP), allowed the synthesis of enantio-enriched compounds, the acylation-reduction leading to the (R,R) addition product. 相似文献
7.
Gaoqing Yuan Zaijun HeJunhua Zheng Zhengwang ChenHuawen Huang Dabin ShiChaorong Qi Huanfeng Jiang 《Tetrahedron letters》2011,52(45):5956-5959
A novel type of carbon dioxide-mediated reaction of diyne alcohols without any metal catalysts was reported. Carbon dioxide held the key to the success of this reaction, in which 3(2H)-furanones were selectively obtained in moderate to high yields. 相似文献
8.
Rong Gao 《Tetrahedron letters》2009,50(43):5914-5916
Furanones are important synthetic intermediates commonly found in natural products, receptor ligands, and drug molecules. Unacceptable yields of substituted furanones obtained using a previously reported Prins reaction led to the development of a modified approach. Readily prepared substituted allylic esters were reacted under Prins reaction conditions catalyzed by a protic acid to provide structurally diverse substituted furanones in modest to good yields. The reaction goes through a protected caprolactone intermediate that was isolated and characterized for selected compounds. The approach supplies an efficient, versatile, and higher yield method for the synthesis of these important heterocyclic intermediates. 相似文献
9.
An efficient palladium-catalyzed cross-coupling reaction of 4-hydroxy-pyrone or 4-hydroxy-2(5H)-furanone with arylboronic acid is described, which affords the 4-substituted-pyrones and 2(5H)-furanones in good yields. This transformation proceeds through a C-OH bond activation under mild conditions. 相似文献
10.
11.
In this paper, stereocontrolled tandem Michael addition-elimination reaction of the novel chiral source, 5-(l-menthyloxy)-3,4-dichloro-2(5H)-furanone, with various thiols and amines has been investigated. A series of new enantiomerically pure compounds, 5–(l-menthyloxy)-4-substituted-3-chloro-2(5H)-furanones, were obtained in good yields with d. e. ? 98% under mild conditions. 相似文献
12.
An efficient stereoselective Michael addition of simple 3(2H)-furanones to α,β-unsaturated ketones has been described. The protocol provides a facile and efficient access to complex 3(2H)-furanones containing adjacent quaternary and tertiary stereocenters in high yields (up to 99%) with good diastereoselectivities (up to 86:14) and excellent enantioselectivities (up to 98% ee) under mild conditions. 相似文献
13.
Anusuya Choudhury Fuqiang JinDengjin Wang Zhe WangGuoyou Xu Dieu NguyenJohn Castoro Michael E PiercePat N Confalone 《Tetrahedron letters》2003,44(2):247-250
Anti-HIV agent β-F-ddA (1) has been synthesized starting from readily available non-sugar, (S)-(+)-Dihydro-5-(hydroxymethyl)-2-(3H)-furanone (4). A highly syn-stereoselective fluorination of the hydroxy lactone 2 generates the key intermediate fluorolactone 5 in a short and concise synthetic sequence. Reduction of 5 followed by bromination generates the aglycon which is glycosylated to generate F-ddA by amination and deprotection. Steric bulk of the 5-protecting group has minimal effect on the steric course of glycosylation. 相似文献
14.
Weishun Liu Lin Fang Yinbo Wan Jianfang Zhang Guisheng Deng Jianbo Wang 《Tetrahedron》2019,75(7):855-861
In AgSbF6/Rh2(OAc)4/DCE system, two-component diastereoselective reactions of 2-diazo-3,5-dioxo-6-ynoates (phosphonates and sulphones) and alkenes provided easy access to 2-cyclopropyl-γ-pyrones through 6-endo-dig cyclization-cyclopropanation. In AgOAc/Rh2(OAc)4/Et3N/DCE system, two-component reaction of 2-diazo-3,5-dioxo-7-aryl-6-ynoates and alkenes afforded 2-cyclopropyl-2-alkylene-3(2H)-furanones through 5-exo-dig cyclization-cyclopropanation. The possible mechanism of reaction is discussed. A simple procedure and mild conditions are significant features of this strategy. 相似文献
15.
Ashraf A Aly 《Tetrahedron》2003,59(32):6067-6073
Reaction of 4-arylidene-2-phenyl-5(4H)-1,3-oxazolones with benzyne afforded predominantly, 3-arylidene-7-hydroxy-7-phenyl-1,4(H)-benzoxazepine-2-ones in addition to their N-phenyl derivatives. However, the reaction of the target oxazolones with an excess of benzyne gave only the N-phenyl derivatives of 1,4(H)-benzoxazepine-2-ones in good yields. The reaction mechanism describing product formation is also explained. Arylation of 1,4(H)-benzoxazepine-2-ones with benzyne proceeded successfully to give the N-phenyl products. 相似文献
16.
Michael Waibel 《Tetrahedron letters》2009,50(23):2767-2769
Three different methodologies for the preparation of highly substituted 2-aryl-quinazolin-4(3H)-ones including short and high-yielding reaction sequences are described. The 2-aryl-substituent of most of the target compounds bears three functional groups. The fluorescence properties of these compounds are presented and potential correlations between structure and optical properties are discussed. 相似文献
17.
Alex F.C. Flores Lucas Pizzuti Darlene C. Flores Claudio M.P. Pereira 《Tetrahedron letters》2010,51(37):4908-4910
The synthesis of 1-alkyl(aryl)-5-(3,3,3-trihalo-2-oxopropylidene)-1H-pyrrol-2(5H)-ones 5, 6a-d from 1-alkyl(aryl)-4-bromo-5-(3,3,3-trihalo-2-oxopropylidene)-1H-pyrrolidin-2-ones 3, 4a-d is reported. The 1-alkyl(aryl)-4-bromo-5-(3,3,3-trihalo-2-oxopropylidene)-1H-pyrrolidin-2-ones 3, 4a-d were obtained from regiospecific bromination of 1-alkyl(aryl)-5-(3,3,3-trihalo-2-oxopropylidene)-1H-pyrrolidin-2-ones 1, 2a-d with molecular bromine. The NMR and X-ray diffraction data showed that 1-alkyl(aryl)-5-(3,3,3-trihalo-2-oxopropylidene)-1H-pyrrolidin-2-ones were brominated at 4-position in the pyrrolidin-2-one ring. 相似文献
18.
Stefano Chimichi Marco BoccaliniBarbara Cosimelli Francesco Dall'AcquaGiampietro Viola 《Tetrahedron》2003,59(28):5215-5223
A convenient route to new 3(2H)-furanones is described through hydrogenolysis and subsequent acidic hydrolysis of isoxazoles. The antiproliferative activity of title compounds were evaluated against leukemia-, carcinoma-, neuroblastoma-, and sarcoma-derived human cell lines in comparison to the natural compound geiparvarin. The structure activity relationship indicated that the maximum in vitro antiproliferative activity correlates with the presence of a heterocyclic ring on the ethenyl moiety. 相似文献
19.
A new attractive and convenient strategy for the synthesis of 3,4-dihydro-6-substituted-3-phenylpyrimidin-2(1H)-ones is described. Photolysis (λ = 254 nm) of 4-allyl-tetrazolones in alcoholic solutions produces the corresponding pyrimidinones as the sole product in nearly quantitative yields, with simultaneous extrusion of molecular nitrogen. Work-up procedures consist in the simple evaporation of the solvent under reduced pressure, in mild conditions. Heats of reaction for the photocleavage process of 4-allyltetrazolones were calculated, indicating high stability of the resulting products. 相似文献
20.
Stereo- and regioselective synthesis of 5-alkylidene (arylidene) and 5-(iodoalkylidene)-pyrrol-2(5H)-ones was achieved from (2Z,4E)-dienamides and (Z)-alk-2-en-4-ynamides by halocyclisation reaction. Selectivity was found to be highly dependent on the nature of the substituents and on the temperature. 相似文献