Design and synthesis of 2(5H)-furanone liquid-crystal compounds based on natural molecules and biphenyl derivatives

Starting from natural molecules, for example l-menthol and amino acids, a series of 2(5H)-furanone liquid-crystal compounds were designed, and synthesized by esterification of N-[5-menthoxy-2(5H)-furanonyl] amino acids with biphenyl-4-ol or biphenyl-4,4′-diol in the presence of dehydrating agents. The structures of all the novel compounds were confirmed by FTIR, ¹H NMR, and mass spectroscopy, and by elemental analysis. The liquid-crystal properties of the target compounds were characterized by differential scanning calorimetry (DSC), X-ray diffraction (XRD), and polarization optical microscopy (POM). The DSC and XRD results showed that some compounds containing short alkyl chains or with the phenyl far from the amino in the amino acid unit formed a mesomorphic phase. Products obtained from biphenyl-4,4′-diol were more likely to form a mesomorphic phase. However, POM revealed no optical texture. These investigations provide, for the first time, a basis for application of 2(5H)-furanones in liquid crystals by combination of different functional units, including biphenyl, l-menthol, and amino acids.     

3-氯-4-二苄胺基-5-甲氧基-2(5H)-呋喃酮的合成与晶体结构

在THF溶液中合成了标题化合物3-氯-4-二苄胺基-5-甲氧基-2(5H)-呋喃酮,并用FT-IR、UV-Vis、1HNMR、13C NMR、MS、元素分析和X-射线衍射等进行了表征。结果表明此化合物属正交晶系,空间群为Pbca,晶胞参数为:a=15.891(16),b=11.126(11),c=19.778(19),α=β=γ=90°,V=3497(6)3,Z=8,Dc=1.306Mg/m3,μ=0.234 mm-1,F(000)=1440。在化合物的分子结构中,两个苯环几乎垂直于呋喃酮平面,且它们与呋喃酮平面的两面角分别为89.38°和88.19°。     

5-烷氧基-2(5H)-呋喃酮在有机合成中的应用

综述了国内外5-烷氧基-2（5H）-呋喃酮通过Michael加成、[3＋2]环加成、光催化加成等反应在有机合成中的应用。参考文献56篇。     

3-羟基-4-甲基-5-乙基-2(5H)-呋喃酮的合成

报道了以草酸二乙酯为原料,制备具有焦糖香味的香料化合物3-羟基-4-甲基-5-乙基-2(5H)-呋喃酮的方法:首先乙基溴化镁与草酸二乙酯通过格氏反应,以约50%产率生成2-氧代丁酸乙酯,然后其在碳酸钾的作用下发生缩合反应,以约94%产率得到3-羟基-4-甲基-5-乙基-5-乙氧羰基-2(5H)-呋喃酮,再通过水解、脱羧反应,得到3-羟基-4-甲基-5-乙基-2(5H)-呋喃酮.路线总收率约36%.     

新型含哌嗪-磺酰胺的2(5H)-呋喃酮类化合物的合成及其抗癌活性

以糠醛为原料,经氧化、醚化和重结晶制得5-甲氧基-3,4-二溴-2(5H)-呋喃酮（4）; 4与哌嗪经Michael加成消除反应制得5-甲氧基-4-哌嗪基-3-溴-2(5H)-呋喃酮（5）; 5与取代磺酰氯经磺酰化反应合成了7 个新型的含哌嗪-磺酰胺的2(5H)-呋喃酮类化合物(7a~7g),其结构经¹H NMR, ¹³C NMR, IR和HR-MS表征。初步的生物活性研究(MTT法)表明,7a~7g均能显著抑制人宫颈癌Hela细胞的增殖,其中5-甲氧基-4-(对乙酰氨基苯磺酰基-哌嗪基)-3-溴-2(5H)-呋喃酮（7f）的抑制活性最佳,其IC₅₀为0.03 μM(24 h)。     

Concise synthesis of chiral 2(5H)-furanone derivatives possessing 1,2,3-triazole moiety via one-pot approach

Combining three bioactive units, such as 2(5H)-furanone, 1,2,3-triazole, and amino acid together into one potential drug molecule with polyfunctional groups, a series of new chiral 2(5H)-furanone derivatives containing 1,2,3-triazole moiety have been designed and synthesized from (5S)-5-alkoxy-3,4-dibromo-2(5H)-furanones, amino acids, propargyl bromide, and organic azides via the sequential three steps, including asymmetric Michael addition–elimination, substitution, and click reaction. The latter two steps, substitution and click reaction could proceed smoothly in a one-pot process. Furthermore, the target products could be directly synthesized via a four-component one-pot approach.     

2(5H)-Furanone and 5-Hydroxy-2(5H)-furanone: Reactions and Syntheses Based on Them

Russian Journal of General Chemistry - This review summarizes the data on 2(5H)-furanone, 5-hydroxy-2(5H)-furanone, and some substituted hydrofuranones with respect to their poorly studied or...     

4－羟基－2，5－二甲基－3（2H）呋喃酮的合成

总结了食品增香剂４－羟基－２．５－二甲基－３（２Ｈ）呋喃国的合成方法，包括近期的合成研究进展，对一些合成方法的优缺点作了评述。参考文献２８篇。     

An Efficient Synthesis of Highly Optically Active 4-Substituted-2（5H）-furanones from Chiral 3-Bromo-2（5H）-furanone

Highly optically active 4-substituted-2(5H)-furanones 6a-6j were obtained in good yields with de≥98% by the tandem Michael addition/elimination reaction of chiral 3-bromo-2(SH)-furanone (4a), which was conveniently prepared starting from 2-furaldehyde under mild conditions. The products were identified on the basis of their satisfactory elemental analysis and spectroscopic data of IR, UV, ^1H NMR, ^13C NMR and mass spectra. The stereochemistry and absolute configuration of this type of compounds were established by the X-ray crystallographic study. The reaction provided a short and efficient synthesis of the interesting highly optically active 4-subsdtuted-2(5H)-furanones containing an active pyrimidine and a purine base group.     

Modification of Synthesis of 3-Chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone(MX)

Addition of chlorine to methyl 3-(dichloromethyl)-4,4-dichlorocrotonate (1), a critical procedure in the total synthesis of the title compound MX, was modified by using novel catalysts. A minor modification in the purification of MX was also described.     

A new synthesis of 5-methylene-2(5H)-furanone derivatives

5-methylene-2(5H)-furanone derivatives are easily obtained by treatment of tertiary 2-furylcarbinols with pyridinium dichromate in dimethylformamide solution. Through this procedure, a natural product, the thiophene lactone isolated from Chamaemelum Nobile L., has been synthesized.     

Asymmetric Diels-Alder reactions with 5-menthyloxy-2-(5H)-furanone

A new class of chiral dienophiles, 5-alkoxy-2(5H)-furanones, has been developed. Both enantiomers of 5-menthyloxy-2(5H)-ftiranone are readily available in enantiomerically pure form, starting from furfural and d- or l-menthol. Excellent diastereoselectivities (d.e. β99%) are obtained in thermal Diels-Alder reactions with several cyclic and acyclic dienes. The use of silyl dienol ethers has resulted in new routes to enantiomerically pure cyclohexanones in a highly regioselective manner.     

Phosphorylation of 3,4-Dichloro-5-hydroxy-2(5H)-furanone with Tributylphosphine

The reaction of 3,4-dichloro-5-hydroxy-2(5H)-furanone with 2 mol of tributylphosphine involves substitution of both chlorine atoms to form an unstable diphosphonium salt. The latter undergoes partial hydrolysis with cleavage of one of the P-C bonds, yielding finally a monophosphorylation product. A probable reaction pathway is considered in terms of quantum chemistry.     

The Photochemical Behaviour of 5,5-Dimethyl-2(5H)-furanone

The photochemical behaviour of the title compound 2c was investigated in various solvents. In benzene and t-butanol photodimerization affords the cis-anti-cis HH- and HT-dimers (H = head, T = tail). In acetonitrile, cyclohexane and 2-propanol, photoreduction competes with photodimerization. The photoreduction products are hydrodimers, solvent adducts and the saturated lactone (the 2H-reduction product). In acetonitrile and cyclohexane H-abstraction by the β-C-atom of the C?C bond is the predominant reduction process. In 2-propanol, solvent adducts to the α- and β-C-atoms are formed in equal amounts. In xanthone-sensitized irradiations the ratio of HH- to HT-dimer is the same as on direct irradiation and the relative rates of conversion of 2c to products in different solvents are also similar under both conditions.     

On the mechanism of a novel 3(2H)-Furanone-2(5H)-furanone rearrangement

The isolation of a stable intermediate product and the mechanism of a novel 3(2H)-furanone-2(5H)-furanone rearrangement that led to the facile preparation of a new class of γ-lactone amides 2 and 4 are discussed.     

Convenient synthesis of 3,4-dichloro-5-hydroxy-2(5H)-furanone glycoconjugates

3,4-Dichloro-5-hydroxy-2(5H)-furanone treated with methyl chloroformate in the presence of diisopropylethylamine (Hünig's base) gave the corresponding carbonate. The labile methoxycarbonyloxy group smoothly undergoes substitution by amino alcohols. The obtained 5-(w-hydroxyalkylamino) mucochloric acid derivatives reacted with peracetylated glucals using triphenylphosphine hydrobromide as a catalyst to give the title muchloric acid glycoconjugates.