Transformations of sym-octahydroxanthene-1,8-diones and 1,8-dioxo-sym-octahydroxanthylium salts in recyclization under the influence of amines

The chemical behavior of 9-R-sym-octahydroxanthene-1,8-diones and salts based on them in recyclization reactions under the influence of amines was studied. The effect of the basicity of the amines on the direction of recyclization was established. A method is proposed for the single-stage synthesis of sym-octahydroacridine-1.8-dione oximes based on 1,8-dioxo-sym-octahydroxanthenes. Conditions were worked out for the oxidation of sym-octahydroxanthene-1,8-diones and N-R-decahydroacridinediones to the corresponding salts. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 32–38, January, 2006.     

Competitive One-Pot Reactions: Simultaneous Synthesis of Decahydroacridine-1,8-diones and 1,8-Dioxo-octahydroxanthenes and Photophysical Characterization

A simple and convenient one-pot method for simultaneously obtaining decahydroacridine-1,8-diones and 1,8-dioxo-octahydroxanthene derivatives is described. A high conversion yielding both products was obtained under the reaction conditions. To understand the optical behavior of the model compounds and their potential use as antenna moieties in bichromophoric systems, the photophysical properties of all samples were studied using ultraviolet–visible absorption and steady-state fluorescence spectroscopy in methanol solutions. For the case of the acridinediones, the fluorescence spectra were found to exhibit the typical emission profile of the locally excited state, whereas, contrary to previous published experimental results, reliable fluorescence emission spectra for the xanthenes derivatives could not be obtained. On the other hand, the poor quantum yields of the synthesized decahydroacridine-1,8-diones were explained based on the benzene-like substitution effect, which favors the intersystem crossing relaxation mechanism.

[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource(s): Full experimental and spectral details.]     

Ceric ammonium nitrate (CAN) catalyzed synthesis of N-substituted decahydroacridine-1,8-diones in PEG

Polyethylene glycol (PEG) was found to be an inexpensive non-toxic and effective medium for the one-pot synthesis of N-substituted decahydroacridine-1,8-diones in the presence of ceric ammonium nitrate (CAN) as the catalyst in high yields. Also, the solvent system can be recovered and reused; making this protocol economically and potentially viable.     

Characteristics of the Dissociative Ionization of 9-Aryl(hetaryl)-3,3,6,6-tetramethyldecahydroacridine-1,8-diones under the Influence of Electron Impact

The mass spectra of 9-aryl(hetaryl)-3,3,6,6-tetramethyldecahydroacridine-1,8-diones have been studied and the basic directions of their dissociative ionization under the influence of electron impact have been elucidated. It has been shown that the decomposition pathways of decahydroacridine-1,8-diones depend on the nature of the substituents at position 10 and is connected with the preferential formation of a pyridinium structure with subsequent retrodiene decomposition of the molecules.     

Nanorod vanadatesulfuric acid (VSA NRs)-catalyzed green synthesis of hexahydroacridine-1,8-diones in solvent-free conditions

Nanorod vanadatesulfuric acid (VSA NRs), as a novel, recyclable and eco-benign catalyst, was used for an efficient synthesis of hexahydroacridine-1,8-diones using 1,3-cyclohexanedione derivatives, aldehydes and ammonium acetate or aniline under solvent-free conditions. VSA was prepared by the reaction of high-purity chlorosulfonic acid and sodium metavanadate. The present method offers some advantages over conventional ones, such as simple procedure and work-up, short reaction times, high yields, stability and reusability of the catalyst and simple purification of the products. Also, some greenness aspects of this method were investigated and compared with data from previous reports.     

新型螺环配体的合成及其在不对称催化氢化反应中的应用

以光学纯的S-2,2′-螺二氢茚-1,1′-二酮为原料,合成了新型螺环氧膦配体(1R,2S,1′S)-1,1′-双(二苯基膦氧)-2,2′-螺二氢茚烷(S-cis,trans-Sp iroB IP),考查了催化剂[Rh(COD)(R-cis,cis-Sp iroB IP)]BF4,[Rh(COD)(S-cis,trans-Sp iroB IP)]BF4和Ir(R-cis,cis-Sp iroB IP)(COD)C l在不对称催化氢化反应中的应用。     

Stereoselective synthesis of 3-alkylidene/alkylazetidin-2-ones from azetidin-2,3-diones

Azetidin-2,3-diones have been used as synthons for the synthesis of C-3 alkylidene/alkylazetidin-2-ones. Some of the 3-alkylazetidin-2-ones are well known for their cholesterol absorption inhibitor activity. A regio and stereoselective Grignard reaction on a keto group followed by dehydration using PPh₃/CCl₄ reagent is a key step in this synthesis. Hydrogenation of the 3-alkylideneazetidin-2-ones provided stereoselectively cis-3-alkylazetidin-2-ones in very good yields.     

Saturated nitrogencontaining heterocycles. 19. Catalytic reduction of 10- and 9,10-substitutedsym-octahydroacridinium salts

10-Methyl(phenyl)- and 9,10-diphenylperhydroacridines have been obtained by the catalytic reduction of 10- and 9,10-substituted sym-octahydroacridinium salts. Selective reduction of the furan ring occurred in the case of 9-(2-furyl)-10-phenyl-sym-octahydroacridinium perchlorate. The stereoisomeric composition of the reaction products has been established and a probable scheme for their formation has been proposed.N. G. Chernyshevsky Saratov State University, Saratov 410600, Russia Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1108–1112, August, 2000.     

Synthesis and Properties of 12(E)-Ethoxyimino Derivatives of 8-Aza-16-thiagona-12,17-diones

The reaction of 8-aza-16-thiagona-1,3,5(10),13-tetraene-12,17-dienes with ethoxyimine in dimethyl sulfoxide yields the corresponding 12(E)-ethoxyimino derivatives. The physicochemical properties of these compounds were studied.     

An efficient one-pot solvent-free synthesis and photophysical properties of 9-aryl/alkyl-octahydroxanthene-1,8-diones

A facile and efficient protocol for the synthesis of 9-aryl/alkyl-3,3,6,6-tetramethyl-1,2,3,4,5,6,7,8-octahydroxanthene-1,8-diones has been developed by one-pot reaction of dimedone with aldehydes in the presence of InCl₃ or P₂O₅ under solvent-free conditions. The optical behaviors of the xanthenediones have been investigated by UV-vis and fluorescence spectroscopy. The present approach offers the advantages of simple methodology, clean and mild reaction, high atom-economy, short reaction time, low environmental impact, wide substrate scope, high yield, and excellent purity.     

Water mediated catalyst-free efficient domino synthesis of 9-(quinolin-2(1H)-one)-xanthene-1,8(5H,9H)-diones using parallel synthesizer

A facile and efficient method for the preparation of 3,4,6,7-tetrahydro-9-(1,2-dihydro-2-oxoquinolin-3-yl)-2H-xanthene-1,8(5H,9H)-diones from substituted 2-chloro-3-formylquinoline and 1,3-cyclohexanedione or dimedone in water at 90 °C using parallel synthesizer is reported. The present methodology offers a tandem-cascade methodology, high yield, and operational simplicity.     

Biological Activity of 5- and 6-Membered Azaheterocycles and Their Synthesis from 5-Aryl-2,3-Dihydrofuran-2,3-diones. (Review)

The biological activity of nitrogen-containing heterocycles obtained by the decyclization or recyclization of 5-aryl-2,3-dihydrofuran-2,3-diones under the action of functionalized amines and diamines has been considered.     

N-碘代乙酰基-N’-生物素-3,6-二氧杂辛烷-1,8-二胺的简便合成

报道N-碘代乙酰基-N’-生物素-3,6-二氧杂辛烷-1,8-二胺(4)的简便合成方法。以3,6-二氧杂辛烷-1,8-二氨和D-生物素为原料,经4步反应,高收率(74.9%)地合成了4,其结构经1H NMR确证。     

Synthesis of 3-alkyloxazolidin-2,4-diones using 2-chloroacetamides, carbon dioxide and 1,8-diazabicyclo[5.4.0]undecene (DBU)

Diazabicyclo[5.4.0]undecene (DBU) reacts with carbon dioxide and N-subsititued-2-chloroacetoamides in a very simple one-step procedure, to give the corresponding 3-substituted oxazolidin-2,4-diones in excellent yields.     

Syntheses of morpholine-2,3-diones and 2-hydroxymorpholin-3-ones: intermediates in the synthesis of aprepitant

The preparation of morpholine-2,3-diones and 2-hydroxymorpholin-3-ones from N-substituted β-amino alcohols is reported. These were useful intermediates in the synthesis and development of aprepitant.     

含脱氢松香骨架的1,8-萘酰亚胺衍生物的合成及其对阴离子的识别

以歧化松香胺为原料合成了6个新型含脱氢松香骨架的1,8-萘酰亚胺衍生物2a～2b和3a～3d,其结构用1H NMR,13C NMR,MS和元素分析进行了表征.对3a～3d进行了阴离子识别研究,并对其识别机理进行了讨论.     

新型手性双膦配体的合成及其催化性能考察

以苯乙烯为原料,通过Sharpless不对称二羟基化反应合成高对映体纯的苯基乙二醇,经环化、亲核开环和取代反应转化为手性碳膦-氧膦型双膦配体.后者与[Rh(COD)Cl]2及NH4PF6作用生成手性膦-铑阳离子催化剂.在α-脱氢氨基酸衍生物的不对称氢化反应中,化学转化率为100%,对映选择性最高达到77?.     

Synthesis and special characterization through X-ray analysis of 1,8-dioxooctahydroxanthenes

Pyran moiety containing heterocyclic compounds have the capability for binding to either side to cyclohex-2-enone rings and to form xanthene derivatives (1,8-dioxooctahydroxanthenes also known as xanthenodiones). These xanthene derivatives display a wide range of biological activities and find applications in laser technologies and photodynamic therapy. This paper describes the preparation, X-ray structural analysis, and theoretical investigation of a series of 1,8-dioxooctahydroxanthenes. The compounds were synthesized via Knoevenagel condensation between different aldehydes and β-diketones. The reactions were performed free of solvents and the 1,8-dioxooctahydroxanthenes were obtained in good yields (70−92%). All the compounds were fully characterized by NMR and IR spectroscopy as well as mass spectrometry. Among the synthesized compounds, seven had their crystal structures elucidated for the first time. In all the new crystal structures, the three fused rings did form an almost completely planar xanthenodione core, except for the side rings that adopt half-chair conformation with both carbons at the flaps oriented toward to the aromatic substituent, or with one of the two carbons pointing opposite to the substituent. Another conformational difference among the new compounds investigated by X-ray diffraction resides in the rotation around the bond axis connecting the xanthenodione core to its aromatic substituent. It was found that different bent levels resulted from weak intermolecular contact patterns. In addition, theoretical calculations for single molecule and dimmers have provided insights into the balance between intramolecular and intermolecular forces driving both conformational features.     

Diastereoselective synthesis of 6-functionalized 4-aryl-1,3-oxazinan-2-ones and their application in the synthesis of 3-aryl-1,3-aminoalcohols and 6-arylpiperidine-2,4-diones

Halocyclocarbamation of benzyl N-(1-phenyl-3-butenyl)carbamates afforded 6-functionalized 4-aryl-1,3-oxazinan-2-ones with moderate to excellent diastereoselectivity depending on the N-substituent. Importantly, in contrast to reported cyclocarbamations of homoallylic carbamates, which are generally trans-diastereoselective, cyclization of N-unsubstituted Cbz-protected homoallylamines led to cis-1,3-oxazinan-2-ones, predominantly. The use of N-benzylated and in situ prepared N-silylated derivatives resulted however in trans-selectivity. Transition states are proposed to explain the stereochemical influence of the N-substituent on the cyclocarbamations. The functionalized 1,3-oxazinan-2-ones could be further elaborated towards biologically or synthetically important 6-arylpiperidine-2,4-diones and 3-aryl-1,3-aminoalcohols.     

甲烷磺酸盐的合成、表征及其催化酯化反应的性能

Methane-sulfonate of copper, cobalt, zinc, lanthanide, praseodymium and neodymium are synthesized and characterized by FTIR and TGA. Methane-sulfonates are used as the catalysts in the esterification of chloroacetic acid with isopropanol. Catalytic activity of methane-sulfonates is studied and compared with other Lewis acids. Under the condition of 1.2/1 molar ratio of isopropanol to chloroacetic acid, 1% catalyst (molar percent of chloroacetic acid), 2.5h reaction time, 80～85℃ temperature and benzene as water-carrying agent. The experi-mental results showed that catalytic activity of Lanthanide methane-sulfonate was the best, the yield of isopropyl chloroacetate reaches 88.7%. Copper methane-sulfonate can be reused for three times without distinct loss of catalytic activity.