α-Polyfluroalkylbenzyl dichlorophosphates as alkylating agents in alkylation of aromatic compounds

On heating, α-polyfluoroalkylbenzyl dichlorophosphates alkylate mesitylene, durene, and naphthalene to give the corresponding aromatic compounds containing the α-polyfluoro-alkylbenzyl fragment as a substituent. Deceased. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1866–1869, September, 1998.     

Interaction of polynitro compounds with difluoroamine

Difluoroamine does not react with tetranitromethane and fluoro-, chloro-, and bromotrinitromethanes in DMF and in acidic media (CF₃COOH, ClSO₃H, FSO₃H, and oleum), but reacts with α-fluoro- and α-(difluoroamino)-α,α-dinitrotoluenes to give substitution products of the difluoroamino group for both the nitro groups,viz., PhC(NF₂)₂F and PhC(NF₂)₃, respectively. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1647–1649, August, 1998.     

Structures of ferrocenylalkyl derivatives of adenine

9-(α-Ferrocenylethyl)adenine was prepared by the reaction of adenine with α-hydroxyethylferrocene in a two-phase aqueous-organic medium in the presence of HBF₄. The structure of the resulting compound was established by X-ray diffraction analysis. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1828–1831, September, 1998.     

Chemical Constituents of Brown Rice Grain (<Emphasis Type="Italic">Oryza sativa</Emphasis>)

One new compound 3,7,11,15,19-pentamethyl-9α,10α,11α,17α,18α-pentahydroxy-n-tetracosan-1-oxy-p-hydroxycaffeoate (oryzaterpenyl caffeoate) (1), together with three known fatty acids linoleic acid, stearic acid and myristic acid were isolated and identified from the rice grain of Oryza sativa. The structure of the new compound was elucidated by 1D and 2D NMR spectroscopic techniques (¹H-¹HCOSY, ¹H-¹³C HETCOR) aided by EI-MS, and IR spectra. __________ Published in Khimiya Prirodnykh Soedinenii, No. 6, pp. 535–537, November–December, 2005.     

Synthesis of α,α′-bis(R-benzylidene)cycloalkanones catalyzed by potassium hydrogen sulfate under solvent-free conditions

Cyclopentanone or cyclohexanone were condensed with aromatic aldehydes to give corresponding α,α′-bis(R-benzylidene)cyclopentanones or α,α′-bis(R-benzylidene)cyclohexanones. The reaction was catalyzed by potassium hydrogen sulfate with a yield of 84–95% under solvent-free conditions.     

Synthesis of α-(acylamino)polyhaloalkylphosphoryl compounds by the reaction of trivalent phosphorus chlorides withN-(α-hydroxypolyhaloalkyl)amides

N-(α-Hydroxypolyhaloalkyl)amides react with trivalent phosphorus chlorides to give α-(acylamino)polyhaloalkylphosphoryl compoundsvia phosphorotropic rearrangement of intermediate phosphites or phosphinites. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1810–1814, September, 1998.     

Synthesis of α,ω-dihalopermethyloligosilanes and silane-siloxane copolymers

α,ω-Dibromopermethyloligosilanes, Br(SiMe₂) _n Br (n=2–4, 6), were prepared by the reaction of dodecamethylcyclohexasilane with bromine. The reaction of (Me₂Si)₆ with MCl₄ (M=Sn, Ti) proceeds with the cleavage of Si−Si- and Si−C-bonds with the formation of α,ω-dichloropermethyloligosilanes, Cl(SiMe₂) _n Cl (n=2–4, 6), and chloro derivatives of cyclohexasilane, Cl _m Si₆Me_12−m (m=1, 2). Silane-siloxane copolymers of regular structure were obtained by heterofunctional copolycondensation of α,ω-dihalopermethyloligosilanes with 1,5-dihydroxyhexamethyltrisiloxane. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1513–1517, August, 1997.     

Synthesis of new cyclolinear permethyloligosilane-siloxanes

α,ω-Bis(heptamethylcyclotetrasiloxanyloxy)oligodimethylsilanes were synthesized for the first time by heterofunctional condensation of hydroxyheptamethylcyclotetrasiloxane with α,ω-dichloropermethyloligosilanes, Cl(Me₂Si) _n Cl (n=2, 4, or 6). The compounds obtained were characterized by spectroscopic methods. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 544–545, March, 1998.     

The ESR study of the structure and reactivity of α-ketoradicals, derivatives of (CF3)3CC(O)C(O)CF3

The structure and reactivity of α-ketoradicals, derivatives of (CF₃)₃CC(O)C(O)CF₃ (1), were studied by ESR spectroscopy. The photoreduction of α-diketone1 in a solution of cyclohexane in perfluorodipentyl ether results in the formation of radicals of two types, (CF₃)₃CC(2)(O(4))·C(3)(O(6)H)CF₃ (1a) and (CF₃)₃C·C(OH)C(O)CF₃ (1b) in a ∼40∶1 ratio. The degree of delocalization of the spin density in two conformers of radical1a was calculated by the MNDO/PM3 method in the UHF approximation. It was established that radicals1a and1b are capable of reversible dimerization. The rate constant of dimerization and the enthalpy of the radical—dimer equilibrium were measured for radical1a. A decrease in the rate of dimerization of radical1a upon addition of complexing solvents ((CF₃)₃COH andp-CF₃C₆H₄CF₃) was found. The influence of the solvents on the rate of dimerization was also detected for α-ketoradical (CF₃)₃CC(O)·C(OSiMe₂Ph)CF₃ (1c). Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 62–67, January, 1998.     

Effect of the temperature on the composition and ratio of hydrolysis products of 1,2-dichlorotetramethyldisilane

The hydrolysis of 1,2-dichlorotetramethyldisilane was studied at different temperatures. At reduced temperatures, the hydrolysis gave permethylcyclo(oxadisilanes) [(Me₂Si)₂O]_n (n = 2 and 3) and α,ω-dihydroxypermethyloligo(oxadisilanes) HO[(SiMe₂)₂O]_mH (m = 1–5). The formation of the latter was proved by the GC-MS method. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 722–724, April, 2006.     

Composition of essential oils from <Emphasis Type="Italic">Salvia anatolica</Emphasis>, a new species endemic from Turkey

The component composition of essential oils produced by steam distillation from flower heads, leaves, and stems of Salvia anatolica (Lamiaceae), a recently described new species endemic from Turkey, was studied by GC/FID and GC/MS. A total of 127 volatile components representing 96% of the oil was identified in essential oil from flower heads and leaves. It was found that the principal oil components of flower heads and leaves were α-pinene (10.9%), β-pinene (6.7%), α-copaene (6.3%), heptacosane (6.2%), and hexadecanoic acid (5.0%). A total of 109 volatile compounds representing 87.9% of the oil was characterized in essential oil isolated from stems. The principal oil components of stems were identified as hexadecanoic acid (27.2%), tetradecanoic acid (15.2%), dodecanoic acid (5.5%), and α-copaene (5.0%). __________ Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 552–555, November–December, 2007.     

Synthesis of new dialkyl α-aminophosphonates and dialkyl α-aminothiophosphonates

New dialkyl α-aminophosphonates and α-aminothiophosphonates were synthesized by reactions of dialkyl phosphites orO,O-dialkyl thiophosphites withN-benzylidene 2-(vinyloxy)ethylamine orN-(4-fluorobenzylidene)-2-(vinyloxy)ethylamine. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1815–1817, September, 1999.     

Asymmetric synthesis of α-substituted alkylphosphonates based on symmetrical dialkyl phosphites

Chiral C₂-symmetrical dialkyl phosphites and C₃-symmetrical trialkyl phosphites, derived from (−)-borneol, (−)-menthol, and 1,2∶5,6-di-O-isopropylidene-α-d-glucofuranose, were studied as the starting reagents for the preparation of chiral organophosphorus compounds. The reactions of C₂-symmetrical dialkyl phosphites and C₃-symmetrical trialkyl phosphites with aldehydes and amines or aldehydes are accompanied by asymmetrical induction at the α-carbon atom to yield optically active α-aminoalkylphosphanates or α-hydroxyalkylphosphonates, respectively. The stereoselectivity of the reaction depends on the structure of the starting compounds and the reaction conditions. Translated fromIzvestiya Akademii, Nauk, Seriya Khimicheskaya, No. 8, pp. 1588–1593, August, 1999.     

Preparative synthesis of the Corey chiral controller for enantioselective dihydroxylation of olefins

A five-step synthesis of both enantiomers of 1,2-di(2,4,6-trimethylbenzylamino)-1,2-diphenylethane,i.e., Corey (R,R)- and (S,S)-controllers for enantioselective dihydroxylation of olefins by osmium tetroxide, starting from α,α′-diphenylglyoxime, has been developed. The key operations in the synthesis are the optical resolution of intermediaterac-1,2-diamino-1,2-diphenylethane into two enantiomers using only (R,R)-tartaric acid and the subsequent enhancement of the enantiomeric purity to >98% by crystallizations of the corresponding Schiff's bis-bases. Analysis of the enantiomeric purity of the controllers can be easily performed using¹H NMR spectra of their salts with (R)-α-methoxy-α-(trifluoromethyl)phenylacetic acid (MosherR-acid). Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 101–105, January, 1997.     

Synthesis of α-amino-β-keto-esters (β-oxodipeptides)

The synthesis of α-amino-β-keto-esters (β-oxo dipeptides) was studied. Corresponding α-amino-β-ketoesters were prepared from BOC-(L)-Valine and BOC-(L)-isoleucine by coupling with (D,L)-threonine hydrochloride and oxidation with Dess-Martin periodinane (DMP) with a total yield of 48% and 38%, respectively. __________ Translated from Chemistry Online, 2007, 70(10): 793–796 [译自: 化学通报]     

Study on interaction between antibiotics and Escherichia coli DH5α by microcalorimetric method

A microcalorimetric technique based on the bacterial heat output was applied to evaluate the influence of antibiotics PIP (Piperacillin Sodium) and composite preparation of PIP and SBT (Sulbactam Sodium) on the growth of E. coli DH5α. The power–time curves of the growth metabolism of E. coli DH5α were studied using a TAM Air Isothermal Microcalorimeter at 37°C. By analyzing the power–time curves, the parameters such as growth rate constants (k), inhibitory ratio (I), the maximum heat power (P _m) and the time of the maximum heat power (t _m) were obtained. The results show that different concentrations of antibiotics affect the growth metabolism of E. coli DH5α. The PIP in the concentration range of 0–0.05 μg mL^–1 has a stimulatory effect on the E. coli DH5α growth, while the PIP of higher concentrations (0.05 –0.25 μg mL^–1) can inhibit its growth. It seems that the composite preparation composed of PIP and SBT cannot improve the inhibitory effect on E. coli DH5α as compared with the PIP.     

Reductive activation of arenes 22. Reactions of the terephthalonitrile radical anion and dianion with α,ω-dibromoalkanes. New evidence for the charge transfer complex as a key intermediate in the reactions of the dianion

The major products of reactions of the terephthalonitrile radical anion with α,ω-dibromoalkanes Br(CH₂)_nBr (n = 3–5) were 4-(ω-bromoalkyl)benzonitriles. Analogous reactions of the terephthalonitrile dianion mainly yielded α,ω-bis(4-cyanophenyl)alkanes. Both transformations are convenient one-step routes to otherwise not easily accessible compounds that are valuable as versatile building blocks. The results of alkylation allow one to suggest that reactions of the dianion with intermediate 4-(ω-bromoalkyl)benzonitriles proceed more rapidly than those with the starting α,ω-dibromoalkanes. This was confirmed by competitive reactions of the dianion with 4-(ω-bromoalkyl)benzonitriles and the corresponding alkyl bromides. To explain such a ratio of the reaction rates, a mechanism was proposed for the reaction of the dianion with 4-(ω-bromoalkyl)benzonitriles. According to this mechanism, a charge transfer complex is a key reaction intermediate. Dedicated to the memory of Academician N. N. Vorozhtsov on the 100th anniversary of his birth. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1069–1077, June, 2007.     

A new component from <Emphasis Type="Italic">Eupatorium cannabinum</Emphasis>

A new compound of formula C₂₈H₄₈O with mp 179-180°C (aqueous ethanol) that was called eucanbin was isolated pure by column chromatography of the ethanol extract of the aerial part of Eupatorium cannabinum L. The structure 24α-methylcholest-20(21)-en-3β-ol was assigned based on chemical and spectral data. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 318–320, May–June, 2009.     

Reaction of frangula-emodin with <Emphasis Type="Italic">α</Emphasis>-bromoalkylmethylketones

The alkylation of 1,6,8-trihydroxy-3-methylanthraquinone (frangula-emodin) by α-bromoalkylmethylketones was investigated. Hydroxyls in the 1-and 8-positions of the β-derivatives were O-acylated. The compositions and structures of the prepared compounds were confirmed by elemental analysis and UV, IR, PMR, and ¹³C NMR spectroscopy. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 324–326, July–August, 2007.