Synthesis of derivatives of 7,8-dihydrothiazolo[2,3-<Emphasis Type="Italic">i</Emphasis>]purine by halocyclization of 6-allylthiopurine

7-Halomethyl-7,8-dihydrothiazolo[2,3-i]purines were synthesized by the reaction of bromine and iodine with 6-allylthiopurine.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, 1551–1553, October, 2004.     

A simple synthesis of (±)-2,6-dimethylocta-5(<Emphasis Type="Italic">Z</Emphasis>),7-diene-4-ol and its attractant activity for the bark beetle <Emphasis Type="Italic">Ips typographus</Emphasis>

A simple method for the synthesis of (±)-2,6-dimethylocta-5(Z),7-diene-4-ol possessing a high pheromone activity for the bark beetle Ips typographus was developed.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2245–2247, October, 2004.     

Synthesis of esters of <Emphasis Type="Italic">m</Emphasis>-C(7)-<Emphasis Type="Italic">iso</Emphasis>-propylcarboran-C(1)-carboxylic acid,natural terpene alcohols,and plant phenols

Previously undescribed esters 1b-21b were prepared by reaction of cetyl alcohol 1a, terpene alcohols 2a-16a, plant phenols 17a-19a, and alcohols 20a and 21a with m-C(7)-iso-propylcarboran-C(1)-carboxylic acid.Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 388–392, September–October, 2004.     

Synthesis of pyrido[2,3-<Emphasis Type="Italic">d</Emphasis>]pyrimidin-7(8<Emphasis Type="Italic">H</Emphasis>)-one derivatives from 5-acetyl-4-aminopyrimidines and β-dicarbonyl compounds

Heating of 5-acetyl-4-aminopyrimidine derivatives with ethyl acetoacetate, ethyl benzoylacetate, and diethyl acetone-1, 3-dicarboxylate in the absence of a base gave the corresponding 6-acylpyrido[2, 3-d]pyrimidin-7(8H)-ones. Under analogous conditions, the reaction with ethyl malonate afforded ethyl 7-oxo-7, 8-dihydropyrido[2, 3-d]pyrimidine-6-carboxylates. The pyridone (rather than hydroxypyridine) structures of the pyridopyrimidines obtained were confirmed by IR spectroscopy.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 770–773, March, 2005.     

Flavonoids of <Emphasis Type="Italic">Scutellaria immaculata</Emphasis> Roots

(±)-5,2′-Dihydroxy-6,7,6′-trimethoxyflavanone, (-)-5,2′-dihydroxy-6,7,8,6′-tetramethoxyflavanone, chrysin, wogonin, apigenin, isoscutellarein, scutellarein, cosmosiin, and the new flavonoid wogonin-7-O-β-D-glucopyranoside, the structure of which was established using chemical transformations and spectral data, were isolated from Scutellaria immaculata roots.__________Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 26–28, January–February, 2005.     

Fabrication of a novel Li<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>MoO<Subscript><Emphasis Type="Italic">y</Emphasis></Subscript> film modified electrode and its application as an electrochemical sensor of iodate

A novel organic gel film modified electrode was simply and conveniently fabricated by casting Li_xMoO_y and polypropylene carbonate (PPC) onto the surface of a gold electrode. The cyclic voltammetry and amperometry studies demonstrated that the Li_xMoO_y film modified electrode has a high stability and a good electrocatalytic activity for the reduction of iodate. In amperometry, a good linear relationship between the steady current and the concentration of iodate was obtained in the range from 3×10^–7 to 1×10^–4 mol L^–1 with a correlation coefficient of 0.9997 and a detection limit of 1×10^–7 mol L^–1.     

DMF acetals as alkylating and cyclizing agents: A facile route to substituted pyrazolo[3,4-d]pyrimidine-4,6(5H,7H)-diones

Summary Several 7-methyl-5-alkyl-2-vinylpyrazolo[3,4-d]pyrimidine-4,6(5H,7H)-diones were prepared. The successful cyclization and alkylation of 6-(-methylbenzylidenehydrazino)-1-methyluracils2a–d using dimethylformamide acetals at high temperature provided6a–d,7a–d, and8a–d. Treatment of6a–d and7a–d with acid afforded 7-methyl-5-alkylpyrazolo[3,4-d]pyrimidine-4,6(5H,7H)-diones9a,b; under the same conditions,3a–d reacted to 7-methylpyrazolo[3,4-d]-pyrimidine-4,6(5H)-dione (4) in good yield.

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DMF-Acetale als Alkylierungs- und Ringschlußreagentien: ein einfacher Weg zu substituierten Pyrazolo[3,4-d]pyrimidin-4,6(5H,7H)-dionen

Zusammenfassung Es wurden verschiedene 7-Methyl-5-alkyl-2-vinylpyrazolo[3,4-d]pyrimidin-4,6(5H,7H)-dione hergestellt. Cyclisierung und Alkylierung der 6-(-Methylbenzylidenhydrazino)-1-methyl-uracile2a–d mit Hilfe von Dimethylformamidacetalen bei hohen Temperaturen ergab6a–d,7a–d und8a–d. Behandlung von6a–d und7a–d mit Säure lieferte die 7-Methyl-5-alkylpyrazolo[3,4-d]pyrimidin-4,6(5H,7H)-dione9a,b; unter den gleichen Bedingungen reagierten3a–d in guter Ausbeute zu 7-Methylpyrazolo[3,4-d]pyrimidin-4,6(5H)-dion (4).

     

Effects of ionization on the phase behavior of poly(<Emphasis Type="Italic">N</Emphasis>-isopropylacrylamide-co-acrylic acid) and poly(<Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>-diethylacrylamide-co-acrylic acid) in water

Phase transitions of poly(N-isopropylacrylamide-co-acrylic acid) (PiPA-AA) and poly(N,N- diethylacrylamide-co-acrylic acid) (PdEA-AA) in water have been investigated by means of turbidimetry, Fourier transform infrared (FTIR) spectroscopy and differential scanning calorimetry (DSC). The phase transition temperatures (T_p) of these copolymers increase with the degree of ionization () of the acrylic acid (AA) units, which in turn is dependent on the pH of the solutions. Apparent values of pK_a for the AA units, determined from the pH dependencies of T_p, are 4.7 and 5.4 for PiPA-AA and PdEA-AA, respectively. Differences between T_p for PiPA-AA and T_p for PiPA homopolymer (T_p) are +1.5 and –0.2 °C/mol% of AA at =1 and 0, respectively. The values of T_p for PdEA-AA are +2.6 (ionic) and –0.5 (nonionic)°C/mol%, indicating that the incorporated AA units have a larger effect on PdEA than on PiPA. DSC measurements performed with each of these copolymers at different pH values show a linear relationship between T_p and the enthalpy of transition (H). IR measurements of PiPA-AA show that the profiles of IR bands from both iPA and AA units exhibit critical changes at T_p of the copolymer. Heating the solution above T_p leads to shifts of the amide II, C–H stretch, and C–H bend bands from the iPA units toward lower wavenumbers, as well as a shift of the amide I band from the iPA units toward higher wavenumbers. A decrease in the intensity of the symmetric C=O stretch IR band from carboxylate anions (1560 cm^–1), and an increase in the intensity of the C=O stretch band from COOH groups (1705 cm^–1) suggest that a partial protonation of the carboxylate groups (COO^–+H⁺COOH) takes place upon the phase transition.     

Structure and stability of closo-hexaboranes and their heteroanalogs

The molecular and electronic structures of closo-hexaboranes B₆H₆ ^2–, B₆H₇ ^–, and B₆H₈ and closo-heterohexaboranes XYB₄H₄ (X = Y = CH, N; X = BH, Y = CH^–, N^–, NH, O) were studed by the ab initio (MP2(full)/6-311+G**) and density functional (B3LYP/6-311+G**) methods. The bridging H atoms in closo-hexaboranes B₆H₇ ^– and B₆H₈ can undergo facile low-barrier migrations around the boron cage (the barrier heights are about 10—15 kcal mol^–1). All heteroboranes having octahedron-like structures with hypercoordinated N and O atoms are rather stable and can be the subject of synthetic research efforts.     

The O–H···O, O–H···N and C–H···O hydrogen bonds in 1,4-dimethylpiperazine mono-betaine monohydrate

1,4-Dimethylpiperazine mono-betaine (1-carboxymethyl-1,4-dimethylpiperazinium inner salt, MBPZ) crystallizes as monohydrate. The crystals are orthorhombic, space group Pccn. Two MBPZ molecules and two water molecules form a cyclic oligomer, (MBPZ·H₂O)₂. The O–H···O and O–H···N hydrogen bonds are of 2.769(1) and 2.902(1) Å, respectively. The dimers interact with the neighboring molecules through the C–H···O hydrogen bonds of 3.234(1) Å. The piperazine ring assumes a chair conformation with the N(4)–CH₃ and N⁺(1)–CH₂COO⁻ groups in the equatorial position and the N⁺(1)–CH₃ group in the axial one. The FTIR spectrum is compared with that calculated by the B3LYP/6-31G(d,p) level of theory.     

<Emphasis Type="Italic">O</Emphasis>- and <Emphasis Type="Italic">N</Emphasis>-Alkylation of <Emphasis Type="Italic">N</Emphasis>-halosuccinimides in ionic reactions with 1-phenyltricyclo [4.1.0.0<Superscript>2,7</Superscript>]heptane

N-Bromo and N-chlorosuccinimides add to 1-phenyltricyclo[4.1.0.0^2,7]heptane in CH₂Cl₂ with cleavage of the C(1)-C(7) bond to give isomeric 1 : 1 Markownikoff-type endo, anti-adducts of the norpinane structure in a ∼3 :7 ratio corresponding to N and O alkylation of succinimide.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No.2, pp. 457–460, February, 2005     

Synthesis of the grapevine moth sex pheromone by Grignard—Schlosser cross-coupling: The effect of the electrophile structure on the stereoisomeric ratio in the reaction products

1-Acetoxy-2E,4Z-heptadiene (4) and 1-bromo-3E,5Z-octadiene (5) were obtained with 90 and 88–92 % configurational purity, respectively, starting from 2,4-heptadiyn-1-ol or 3,5-octadiyn-1-ol. The Li₂CuCl₄-catalyzed cross-coupling of the allylic acetate4 with 5tert-butoxypentylmagnesium chloride affords 1-tert-butoxy-7E,9Z-dodecadiene (11) contaminated with 25 % of minor stereoisomers in 54–60 % overall yield. Under similar conditions, the homoallylic bromide5 reacts with 4-tert-butoxybutylmagnesium chloride to give in 50–52 % yield another sample of diene11 containing 17 % of minor stereoisomers. If the latter coupling is carried out with enyne8 instead of5 followed bycis-hydrogenation of the triple bond in the resulting product, the configurational purity of diene11 is as high as 84.7 % (45 % overall yield). The reaction of11 with Ac₂O in the presence of FeCl₃ leads directly to the target 7E,9Z-dodecadienyl acetate (1) with somewhat lower configurational purity than that of the starting ether11.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1133–1137, June, 1993.     

Optically pure acyclic bifunctional compounds from (−)-menthone. Synthesis ofR-4-methyl-1-nonanol,the sex pheromone of the larger flour beetle (Tenebrio molitor L.)

A number of novel methyl-branched chirones were prepared starting from (–)-menthone and making use of a novel, efficient, and selective oxidant, decanepersulfonic acid (DPSA). Optically pure (4R)-methyl-1-nonanol, the sex pheromone of the larger flour beetle (Tenebrio molitor L.), was synthesized.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1301–1303, July, 1993.     

Crystal structure and IR spectrum of 1-O-α- -glucopyranosyl- -mannitol–ethanol (2/1)

1-O-α- -Glucopyranosyl- -mannitol–ethanol (2/1), (C₁₂H₂₄O₁₁)₂–C₂H₅OH, crystallizes in the monoclinic space group P2₁ with unit cell dimensions a=11.4230(8) Å, b=9.525(4) Å, c=15.854(2) Å, β=102.751(7)° and V=1682.4(7) ų, Z=2, D_x=1.45 Mg m⁻³, λ (Mo-K_α)=0.71069 Å, μ=0.128 mm⁻¹, F(000)=788 and T=293(2) K. The structure was solved by direct methods and refined by least-squares calculations on F² to R₁=0.0371[I>2σ(I)], and 0.0930 (all data, 3542 independent reflections, R_int=0.021). There are two molecules of glucopyranosylmannitol (GPM) and one ethanol molecule in the asymmetric unit, and the glucopyranosyl ring adopts a chair conformation in both GPM molecules. Bond lengths and angles accord well with the mean values of related structures. The conformation along the mannitol side chain for one of the GPM molecules was the same as for the known polymorphs of -mannitol, while the conformation of the other molecule was different, indicating different conformational arrangements in the terminal carbon atoms of the mannitol side chains of the two GPM molecules. The structure in 1-O-α- -glucopyranosyl- -mannitol–ethanol (2/1) is held together by a very complex hydrogen bonding system, which consists of an infinte chain propagating along the b-axis and a discontinuous chain, which binds the ethanol molecule to the structure. The FTIR spectra for anhydrous GPM, GPM dihydrate and GPM–ethanol (2/1) were recorded. Both IR and X-ray results indicate the extensive hydrogen bonding in crystalline state.     

<Emphasis Type="Italic">Ferula gummosa</Emphasis> Fruits: An Aromatic Antimicrobial Agent

Ferula gummosa Boiss. (Apiaceae) fruit volatile oil was analyzed by GC/MS. Seventy-three components (96.89%) were identified, and the major components were β-pinene (43.78%), α-pinene (27.27%), and myrcene (3.37%). The antimicrobial activity of the oil was tested on three strains of Gram positive bacteria (Staphylococcus aureus, S. epidermis, and Bacillus subtilis), three strains of Gram negative bacteria (Escherichia coli, Salmonella typhi, and Pseudomonas aeruginosa), and two strains of fungi (Candida albicans and C. kefyr). The essential oil remarkably inhibited the growth of the tested microorganisms. The results indicate that the fruits have potential for use as an aromatic antimicrobial agent.__________Published in Khimiya Prirodnykh Soedinenii, No. 3, pp. 252–254, May–June, 2005.     

Synthesis of 7E,9Z-dodecadienyl acetate,the sex pheromone ofLobesia botrana Shiff

Two syntheses of 7E,9Z-dodecadienyl acetate from 1,3-butadiyne were carried out using either 2E,4Z-heptadienyl acetate or 1-bromo-3E,5Z-octadiene as the key intermediates. The latter underwent organocopper cross-coupling with the respective complementary Grignard reagents (prepared from the corresponding 1-tert-butoxy--chlorohydrins) as alkylating agents.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 766–768, April, 1993.     

Spectral studies on the reaction of chromium (VI) compounds with aminophosphonic esters

The studies on reaction of newly obtained aminophosphonic acid diethyl ester derivatives of fluorene with Cr₂O₇ ^2–, CrO₄ ^2–, CrO₃Cl^– and CrO₃ have been investigated using electronic, infrared,Raman and NMR spectral methods. It has been found that the resulting compounds are of the type (AH)₂Cr₂O₇, whereA stands for the organic part of the molecule. The organic cation and solvent effects on the electronic states of pseudotetrahedrally arranged Cr(VI) anions are discussed.

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Spektroskopische Untersuchungen über Reaktionen von Chrom(VI)-Verbindungen mit Aminophosphonsäure-Estern

Zusammenfassung Es wurden Elektronen-, Ultrarot-,Raman- und NMR-spektroskopische Untersuchungen beschrieben, die an neuen Verbindungen durchgeführt wurden, welche als Reaktionsprodukte von Cr₂O₇ ^2–, CrO₄ ^2–, CrO₃Cl^– und CrO₃ mit Aminophosphonsäurediethylesterderivaten von Fluorene synthetisiert worden waren. Es wurde festgestellt, daß diese Verbindungen mit einer allgemeinen Formel (AH)₂Cr₂O₇ beschrieben können werden, in derA den organischen Teil der Verbindungen bedeutet. Der Einfluß des organischen Kations wie auch der von Lösungsmitteln auf die Elektronenzustände des pseudotetraedrischen Cr(VI)-Anions wurde gleichfalls untersucht.

     

Synthesis of dialkoxy- and alkoxy-amino-disubstituted derivatives of B12H12 2−

Dichloromethoxymethane reacts with the sodium salt ofcloso-dodecahydrododecaborate Na₂B₁₂H₁₂ to give disubstituted cluster, which readily decomposes when treated with various reagents. This cluster reacts with water, forming the previously described 1,7-B₁₂H₁₀(OH)_{2 2–}reaction with alcohols results in a novel 1,7-dialkoxy derivative, whereas interaction with morpholine in acetone solution affords the novel anion, 1-O-I-Prⁱ-7-O(CH₂CH₂)N-B₁₂H₁₀ ^2–. All of these derivatives were isolated as cesium salts and characterized by one- and two-dimensional NMR techniques.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 421–424, March, 1995.     

Lithiated γ-O-functionalized propyl phenyl sulfides and sulfones of the type Li[CH(SOxPh)CH2CH2OR] (x = 0, 2). [Li{CH(SPh)CH2CH2Ot-Bu}(tmeda)] – A structurally characterized organolithium inner complex

Lithiation of O-functionalized alkyl phenyl sulfides PhSCH₂CH₂CH₂OR (R = Me, 1a; i-Pr, 1b; t-Bu, 1c; CPh₃, 1d) with n-BuLi/tmeda in n-pentane resulted in the formation of α- and ortho-lithiated compounds [Li{CH(SPh)CH₂CH₂OR}(tmeda)] (α-2a–d) and [Li{o-C₆H₄SCH₂CH₂CH₂OR)(tmeda)] (o-2a–d), respectively, which has been proved by subsequent reaction with n-Bu₃SnCl yielding the requisite stannylated γ-OR-functionalized propyl phenyl sulfides n-Bu₃SnCH(SPh)CH₂CH₂OR (α-3a–d) and n-Bu₃Sn(o-C₆H₄SCH₂CH₂CH₂OR) (o-3a–d). The α/ortho ratios were found to be dependent on the sterical demand of the substituent R. Stannylated alkyl phenyl sulfides α-3a–c were found to react with n-BuLi/tmeda and n-BuLi yielding the pure α-lithiated compounds α-2a–c and [Li{CH(SPh)CH₂CH₂OR}] (α-4a–b), respectively, as white to yellowish powders. Single-crystal X-ray diffraction analysis of [Li{CH(SPh)CH₂CH₂Ot-Bu}(tmeda)] (α-2c) exhibited a distorted tetrahedral coordination of lithium having a chelating tmeda ligand and a C,O coordinated organyl ligand. Thus, α-2c is a typical organolithium inner complex.Lithiation of O-functionalized alkyl phenyl sulfones PhSO₂CH₂CH₂CH₂OR (R = Me, 5a; i-Pr, 5b; CPh₃, 5c) with n-BuLi resulted in the exclusive formation of the α-lithiated products Li[CH(SO₂Ph)CH₂CH₂OR] (6a–c) that were found to react with n-Bu₃SnCl yielding the requisite α-stannylated compounds n-Bu₃SnCH(SO₂Ph)CH₂CH₂OR (7a–c). The identities of all lithium and tin compounds have been unambiguously proved by NMR spectroscopy (¹H, ¹³C, ¹¹⁹Sn).     

Fatty Acids from the Sponge <Emphasis Type="Italic">Tedania dirhaphis</Emphasis>

The fatty acid (FA) composition of total lipids from the marine sponge Tedania dirhaphis from the Sea of Okhotsk was studied. GC and GC-MS identified 50 acids, particular attention being paid to components with 14–22 C atoms. Acids 16-Me-19:0, 10,14-Me₂-15:1(Δ6), 18:1(Δ6), 18:1(Δ8), and 22:1(Δ16) were observed and identified for the first time in sponges. The main FA in lipids from T. dirhaphis was 28:3(Δ5,9,21), the relative content of which reached 63.3%.__________Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 233–236, May–June, 2005.