无外加催化剂条件下芳香醛与活性亚甲基化合物的缩合反应和迈克尔加成反应

在DMF溶剂中，不外加催化剂使芳香醛(1)与2,2-二甲基-1,3-二氧六环-4,6-二酮(2)发生缩合反应生成2,2-二甲基-5-芳亚甲基-1,3-二氧六环-4,6-二酮(3a～f)。在同样条件下，芳香醛与5,5-二甲基-1,3-环己二酮(4)则发生缩合和迈克尔加成反应生成2,2'-芳亚甲基双(3-羟基5,5-二甲基-2-环己烯-1-酮)(5a～h)。用单晶X-射线分析法确定了产物5b的晶体结构。     

Synthesis and Crystal Structure of 5,5-Dimethyl-2-(4-chlorophenyl)(3-hydroxy-5,5-dimethyl-2-cyclohexen-1-one-2-yl)methyl-3-(4-methoxyphenylamino)-2-cyclohexene-1-one

The title compound 5,5-dimethyl-2-(4-chlorophenyl)(3-hydroxy-5,5-dimethyl-2-cyclohexen-1-one-2-yl)methyl-3-(4-methoxyphenylamino)-2-cyclohexen-1-one has been synthesized,and its crystal structure was characterized by X-ray single-crystal diffraction. The crystal belongs to monoclinic,space group P21/c with a=9.4193(13),b=26.915(4),c=21.188(3),β =101.906(3)°,V =5256.2(13)3,Z =4,C60H68Cl2N2O8,Mr=1016.06,Dc=1.284 g/cm3,F(000)=2160,λ(MoKα)=0.71073,μ=0.182 mm–1,R=0.0530 and wR=0.1131 for 4128 observed reflections (I>2σ(I)). X-ray analysis reveals that there are two independent molecules in the unit and the cyclohexenone rings adopt different conformations. In addition,there are four intramolecular hydrogen bonds in the title molecule.     

Synthesis of phenyl-substituted derivatives of decahydrophenanthridine-1, 7-dione and hexahydro-8-isoquinolone

2-Bromo-2-aroylcydohexan-1-ones were prepared by bromination of 2-aroylcyclohexan-1-ones with Nbromosucccinimide and were isomerized into 6-bromo-2-aroylcyclohexan-1-ones in attempted dehydrobromination by heating in organic solvents. The reaction of 2-benzoyldimedone with oxalyl chloride was investigated. The 2-benzoyl-3-chloro-5,5-dimethyl-2-cyclohexen-1-one obtained formed 2-benzoyl-5,5-dimethyl-2-cyclohexen-1-one in reduction with zinc activated with silver acetate. The cyclohexenone was reacted with some enaminocarbonyl compounds, yielding derivatives of decahydrophenanthridine-1,7-dione and hexahydro-8-isoquinolone.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 631–635, May, 1992.     

Reactions of 2-cyano-3-ethoxy-5,5-dimethyl-2-cyclohexen-1-one with 2-amino- and 2-hydrazionobenzimidazoles

The reactions of 2-cyano-3-ethoxy-5,5-dimethyl-2-cyclohexen-1-one with 2-amino- and 2-hydrazinobenzimidazoles gave 1-oxo-3,3-dimethyl-11-amino-1,2,3,4-tetrahydroquinazolino[3,2-a]benzimidazole and 2-(2-benzimidazolyl)-3-amino-4-oxo-6,6-dimethyl-4,5,6,7-tetrahydroindazole, respectively.Riga Technical University, Riga LV-1658. Latvian Institute of Organic Synthesis, Riga LV-1006. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 235–240, Feburary, 1997.     

4-Azaindane-1,3-dione derivatives

6,6-Dimethyl-2-methyl(or phenyl)-9-ethoxycarbonyl-5,6,7,8-tetrahydro-4-azabenz[f]indane-1, 3,8-triones were synthesized by reaction of 3-ethoxalyl-5-R-cyclopentaae-1,2,4-triones with 3-amino-5,5-dimethyl-2-cyclohexen-1-one. The products were alkylated, brominated, reduced, and hydrolyzed.     

6,11-Dioxa-D-homoanalogs of steroids by reaction of 2-acetyl-2-cyclohexen-1-ones with 4-hydroxycoumarins

Unsubstituted 2-acetyl-2-cyclohexetz-1-one reacts with 4-hydroxycoumarin following the pattern of a Diels -Alder heterodiene condensation to form 12-methyl-6,11-dioxa-9-hydroxy-D-homo-1,3,5(10), 12-tetraene-7,17a-dione. In the case of 2-acetyl-5,5-dimethyl-2-cyclohexen-1-one, reaction with both 4-hydroxy- and 4,7-dihydroxycoumarin follows the pattern of a Michael addition with the formation of 3-(2-acetyl-5,5-dimethyl-3-oxocyclohexyl)-4-hydroxy-and 4,7-dihydroxy coumarin respectively. Dehydration of both types of adduct gives 6,11-dioxa-D-homoanalogs of steroids.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 345–348, March, 1994.     

Isolation and identification of three urinary metabolites of retinoic acid in the rat.

After the intraperitoneal administration of high doses of ¹⁴C- and ³H-labelled retinoic acid ( 1 ) to rats three major urinary metabolites have been isolated in microgram amounts by use of column, thin-layer and high-pressure liquid chromatography. Their structures were elucidated by mass spectroscopy and Fourier transform ¹H-NMR. spectroscopy as 2 (5-methyl-5-[2-(2,6,6-trimethyl-3-oxo-1-cyclohexen-1-yl)vinyl]-2-tetrahydrofuranone), 3 (5-[2-(6-hydroxymethyl-2,6-dimethyl-3-oxo-1-cyclohexen-1-yl)vinyl]-5-methyl-2-tetrahydrofuranone) and 4 (6-(6-hydroxymethyl-2,6-dimethyl-3-oxo-1-cyclohexen-1-yl)-4-methyl-4-hexenoic acid). In these metabolites the tetraene side chain of 1 is shortened and the cyclohexene ring oxidized. The radioactivity of 2 and 3 accounted for about 10% (0.9% of the dose) each, metabolite 4 for about 6% (0.5% of the dose) of the total urinary radioactivity.     

离子液体介质中FeCl3•6H2O催化下芳香醛与5,5-二甲基-1,3-环己二酮的缩合反应

考察了在离子液体1-正丁基-3-甲基咪唑四氟硼酸盐([bmim][BF₄])介质中, 芳香醛与5,5-二甲基-1,3-环己二酮的缩合反应. 实验结果表明, 在催化量的FeCl₃•6H₂O存在下, 该反应可高产率地生成氧杂蒽二酮类化合物3; 而在TMSCl/FeCl₃•6H₂O复合催化体系的催化下, 则得到氧杂蒽二酮类化合物的开环衍生物4, 反应具有非常好的选择性. 该论文提供的方法操作简单、产率高、选择性好而且对环境友好. 在反应结束后, 所用催化剂及离子液体都很容易回收, 并能有效重复使用.     

Synthesis of decahydrophenanthridine-1,7-dione and hexahydroisoquinol-8-one derivatives in the reaction of 2-acetyl-2-cyclohexene-1-ones with conjugated enaminocarbonyl compounds

Derivatives of decahydrophenanthridine-1,7-dione were obtained by the reaction of 2-acetyl-2-cyclohexen-1-ones with enamines of cyclic -diketones (dihydroresorcinol, dimedone). Derivatives of hexahydroisoquinol-8-one having electron-acceptor substituents at the 4-position were obtained by the reaction of 2-acetyl-5,5-dimethyl-2-cyclohexen-1-one with acyclic enaminocarbonyl compounds. The reaction mechanism is discussed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 66–71, January, 1990.     

An efficient synthesis of N1-substituted 2,5-dioxo-1,2,5,6,7,8-hexahydro-3-quinolinecarboxamide via enolate salts

Various 2-(2-cyano-2-carbamoyl-1-ethenyl)-5,5-dimethyl-3-oxo-1-cyclohexen-1-olates substituted in the amide group with dialkylammonium or sodium cations were prepared via reactions of N-substituted cyanoacetamides with dimedone-DMFDMA adduct by a one-pot, two-step protocol. The salts obtained were used in reactions with N-nucleophiles for further synthesis of the N1-substituted 2,5-dioxo-1,2,5,6,7,8-hexahydro-3-quinolinecarboxamides that are analogues of well-known pharmaceuticals. The structure of the salts and the N1-substituted 2,5-dioxo-1,2,5,6,7,8-hexahydro-3-quinolinecarboxamides was established by means of spectroscopic and X-ray diffraction studies.     

Hydrolysis of Bis[5,5-dimethyl-3-(4-oxa-1-azoniacyclohexylidene)-1-cyclohexenyl] Sulfide Diperchlorate

Hydrolysis of bis[5,5-dimethyl-3-(4-oxa-1-azoniacyclohexylidene)-1-cyclohexenyl] sulfide diperchlorate, as well as of bis(5,5-dimethyl-3-thioxo-1-cyclohexenyl) sulfide, in the system MeCN-Et₃N yields a mixture of bis(5,5-dimethyl-3-oxo-1-cyclohexenyl) sulfide and isomeric 5,5-dimethyl-3-oxo-1-cyclohexenyl 3,3-dimethyl-5-oxo-1-cyclohexenyl sulfide. The structure of the products and their ratio were established by ¹H and ¹³C NMR and IR spectroscopy.     

SuperQuat N-acyl-5,5-dimethyloxazolidin-2-ones for the asymmetric synthesis of alpha-alkyl and beta-alkyl aldehydes

The proclivity of alpha-branched N-2'-benzyl-3'-phenylpropionyl derivatives of (S)-4-benzyl-5,5-dimethyl-, (S)-4-phenyl-5,5-dimethyl-, (S)-4-isopropyl-5,5-dimethyl-, (S)-4-benzyl- and (S)-4-benzyl-5,5-diphenyl-oxazolidin-2-ones to generate directly 2-benzyl-3-phenylpropionaldehyde upon hydride reduction with DIBAL is investigated. The (S)-4-benzyl-5,5-dimethyl-derivative proved optimal for inhibition of endocyclic nucleophilic attack, giving 2-benzyl-3-phenylpropionaldehyde in good yield upon reduction. Application of this methodology for the asymmetric synthesis of chiral aldehydes via diastereoselective enolate alkylation of a range of (S)-N-acyl-4-benzyl-5,5-dimethyloxazolidin-2-ones to afford and array of alpha-substituted-N-acyl-5,5-dimethyloxazolidin- 2-ones (85-94% de) and subsequent reduction with DIBAL afforded directly non-racemic alpha-substituted aldehydes without loss of stereochemical integrity (87-94% ee). The extension of this protocol for the asymmetric synthesis of beta-substituted aldehydes is demonstrated, via the diastereoselective conjugate addition of a range of organocuprates to (S)-N-acyl-4-phenyl-5,5-dimethyloxazolidin-2-ones which proceeds with high diastereoselectivity (generally > 95% de). Reduction of the conjugate addition products with DIBAL gives non-racemic beta-substituted aldehydes in high yields and in high ee (generally > 95% ee). This methodology is exemplified by the asymmetric synthesis of (R)-3-isopropenylhept-6-enal, which has previously been used in the synthesis of (3Z,6R)-3-methyl-6-isopropenyl-3,9-decadien-1-yl acetate, a component of the sex pheromones of the California red scale.     

Photoactivation of amino-substituted 1,4-benzoquinones for release of carboxylate and phenolate leaving groups using visible light

Upon exposure to visible light, 2-pyrrolidino-substituted 3,6-dimethyl-1,4-benzoquinones photocyclize to give benzoxazolines with quantum yields of 0.07-0.10 in CH2Cl2, 0.02-0.04 in CH3CN, and <0.01 in 30% aq CH3CN. With carboxylate or phenolate leaving groups incorporated via coupling to a 5-hydroxymethyl group of the quinones, the photocyclizations give benzoxazolines that eliminate the leaving groups in a dark reaction. Lifetimes for elimination of 4-YC6H4OH in 30% phosphate buffer in CD3CN (pD 7) at 17 degrees C are 13.1, 0.54, and 0.13 h for Y = H, CF3, and CN, respectively, and the linear equation log k (h(-1)) = 0.998(-pKa) + 8.80 gives a best fit to the data. Carboxylate leaving groups are rapidly eliminated upon photolysis of the quinones in aq CH3CN to produce an o-quinone methide intermediate that is trapped by 4 + 2 cycloaddition with unreacted starting material or with added 3-(dimethylamino)-5,5-dimethyl-2-cyclohexen-1-one. The ortho-quinone methide is observed at 339 and 455 nm by conventional absorption spectroscopy and gives a pseudo-first-order fit of the decay kinetics with tau1/2 = 34.9 min in 30% phosphate buffer in CH3CN at 20 degrees C.     

1,7-Dithioxo Systems. Synthetic Routes to Bis(5,5-dimethyl-3-thioxo-1-cyclohexenyl) Sulfide

Synthetic routes to bis(5,5-dimethyl-3-thioxo-1-cyclohexenyl) sulfide have been studied. The title compound can be obtained by reaction of 3-chloro-5,5-dimethyl-2-cyclohexenethione with sodium thiosulfate and by condensation of 3-mercapto-5,5-dimethyl-2-cyclohexenethione. The reaction of bis(5,5-dimethyl-3-oxo-1-cyclohexenyl) sulfide with hydrogen sulfide and hydrogen chloride yields 3-oxo-3'-thioxobis(5,5-dimethyl-1-cyclohexenyl) sulfide.     

Stereochimie d'heterocycles du groupe IVB—II : Syntheses stereoselectives d'hydrogeno-1 et d'alkyl-1 sila-1 cyclobutanes

The reaction between n-butyllithium and 1,2 (or 1,3)-dimethyl-1-t-butoxy-1-silacyclobutanes proceeds with retention of configuration at silicon, and yields 10/90 (or 80/20) Z/E mixture of 1,2 (or 1,3)-dimethyl-1-n-butyl-1-silacyclobutanes. Methylation of 2 (or 3)-methyl-1-t-butoxy-1-silacyclobutanes (Z/E = 15/85 or 65/35) by methylmagnesium iodide gives 15/85 (or 65/35) Z/E mixture of 1,2 (or 1,3)-dimethyl-1-silacyclobutanes. The proposed configurations for substituted silacyclobutanes are supported by spectroscopic data (RMN) and chemical results (correlation of configuration and stereomutation of hydrogenosilacyclobutanes).     

2-(1-Isonicotinoylhydrazinoalkylidene)-5,5-dimethyl-1,3-cyclohexanediones and their polychromism. A new type of compound with intramolecular charge transfer through the hydrazonocarbonyl bridge

The product of condensation of 2-formyldimedone with the hydrazide of isonicotinic acid, namely 2-isonicotinoylhydrazinomethylene-5,5-dimethyl-1,3-cyclohexanedione, has been obtained in three forms — red, colorless, and yellow — which with methyl iodide give one and the same iodide 2-[N-(1-methyl-4-pyridiniumcarbonyl)hydrazinomethylene]-5, 5-dimethyl-1, 3-cyclohexanedione. On the basis of UV spectra and x-ray structure analysis of this betaine and also the dark-red iodide of N-(4-diethylaminobenzal)-N-(1-methyl-4-pyridiniumcarbonyl)hydrazine, it has been shown that intramolecular charge transfer in these linear molecules proceeds along the system of bonds D:-RC=N-NH-CO-A through the hydrazonocarbonyl bridge, which does not interrupt the conjugation chain. The existence of colored forms of the 2-isonicotinoylhydrazinomethylene-5,5-dimethyl-1,3-cyclohexanedione can be explained by an admixture of the betaine form.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 489–498, April, 1993.     

水溶剂中芳醛与5，5－二甲基－1，3－环己二酮的反应

芳醛1与5，5－二甲基－1，3－环己二酮（2）在氯化三乙基苄基铵（TEBA）催 化下在水中生成2，2'－芳业甲基双（3－羟基－5，5－二甲基－2－环己烯－1－酮 ）（3），若在体系中有对甲苯磺酸存在时则生成3，3，6，6－四甲基－9－芳基－ 1，8－二氧代八氢化氧杂蒽（4）或3，3－二甲基－9－（3－羟基－5，5－二甲基 －2－环己烯－1－酮－2－基）－1－氧代四氢代氧杂蒽（6）而不是生成3，产率接 近定量。     

Synthesis of Urinary Metabolites of Retinoic Acid

Urinary metabolites 5-methyl-5-[2-(2,6,6-trimethyl -3-oxo-1-cyclohexen-1-yl)-vinyl]-2-tetrahydrofuranone (1) and 5-[2-(6-hydroxymethyl-2, 6-dimethyl-3-oxo-1- cyclohexen-1-yl)vinyl]-5-methyl-2-tetrahydrofuranone (2) of retinoic acid have been synthesized from 4-[2,2,6-trimethyl-3-(tetrahydro-2 H -pyran-2-yl)oxy-1-cyclohexen-1-yl]-3-buten-2-one (4) and methyl 2-(3,3-ethylenedioxy-1-butenyl)-1, 3-dimethyl-4-oxo-2-cyclohexene-1-carboxylate (5) .     

Hexahydro-8-isoquinolones with electron-acceptor substituents in position 4

By the interaction of 2-acetyl-5,5-dimethyl-2-cyclohexen-1-one with certain nitroenamines, a number of hexahydro-8-isoquinolones with a nitro group in position 4 have been obtained; potentials of their electrochemical oxidation have been determined, and a possible mechanism and manifestation of structural effects in this process have been suggested and discussed. The structure of 1,3,6,6-tetramethyl-4-nitro-2, 4a-5,6,7,8-hexahydro-8-isoquinolone has been established by means of x-ray diffraction analysis. Latvian Institute of Organic Synthesis, Riga LV-11006. E-mail: aiva@osi.lanet.lv. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1372–1380, October, 1998.     

1H NMR utilization of through-space effects. II—conformation of dienic ketones

The configurational and conformational assignments of the carbonyl group in the Z- and E-1-(3-substituted-5,5-dimethyl-2-cyclohexen-1-ylidene)-2-butanones are carried out using only the through-space effects of the carbonyl group. It is demonstrated that, regardless of the Z- or E-configuration or the nature of the substituent in position 3, the conformation of the carbonyl group is always s-cis.