Diterpenoide Drüsenfarbstoffe aus Labiaten: Coleone U,V, W und 14-O-Formyl-coleon-V sowie 2 Royleanone aus Plectranthus myrianthus BRIQ.; cis- und trans-A/B-6, 7-Dioxoroyleanon

Leaf-gland Pigments: Coleons U, V, W, 14- O -Formyl-coleon-V, and two Royleanones from Plectranthus myrianthus BRIQ. ; cis - and trans -A/B-6,7-Dioxoroyleanones From leaf-glands of the South-African P. myrianthus (Labiatae) the following diterpenoids have been isolated and their structures established: coleon U, C₂₀H₂₆O₅ (6, 11, 12, 14-tetrahydroxy-abieta-5, 8, 11, 13-tetraene-7-one, 2a ); coleon V, C₂₀H₂₆O₅ (11, 12, 14-trihydroxy-abieta-8, 11, 13-triene-6, 7-dione, 4a ); coleon W, C₂₂H₂₈O₈ (16(or 17)-acetoxy-6, 11, 12, 14, 17 (or 16)-pentahydroxy-abieta-5, 8, 11, 13-tetraene-7-one, 6 ); 14-O-formyl-coleon-V, C₂₁H₂₆O₆ (14-formyloxy-11, 12-dihydroxy-abieta-8, 11, 13-triene-6, 7-dione, 4b ); 7α-formyloxy-6β-hydroxyroyleanone, C₂₁H₂₈O₆ (7α-formyloxy-6β, 12-dihydroxy-abieta-8, 12-diene-11, 14-dione, 1a ); the already known 6β, 7α-dihydroxyroyleanone ( 1c ) and a dimeric abietane derivative whose structure is not yet elucidated. This is the first record of a co-occurrence of coleons and royleanones in the same plant. In the course of chemical investigations of 4a and 4b the highly oxidized trans- and cis-A/B-6,7-dioxoroyleanones ( 5a and 5b ) were obtained.     

Coleon D,ein Diterpen aus Coleus aquaticus Guercke mit trans-A/B-6,7-Dioxostruktur

Coleon D, C₂₀H₂₆O₆ a new orange red diterpenoid hydroquinone has been isolated from the yellow glands on the leaves and inflorescences of Coleus aquaticus Guercke (Labiatae). Its structure has been determined as 11,12,14,16-tetrahydroxy-5α-abieta-8,11,13-trien-6,7-dion ( 1 ) Therefore it is a tautomer of Coleon C ( 2 ). Coleon D is the precursor of Coleon C.     

Composition of the neutral fraction of the resin ofPinus sibirica R. Mayr.

Summary 1. The high-boiling neutral fraction of the resin of the Siberian cedar contains abietinal, a diterpene diol C₂₀H₃₄O₂, and the diterpene alcohol cembrol C₂₀H₃₄O₂ which has a 14-membered ring and three double bonds; the dehydration of cembrol gives the diterpene hydrocarbon cembrene C₂₀H₃₂; the probable structure of cembrol is 14-isopropyl-3, 7, 11-trimethylcyclotetradeca-1, 3, 6-trien-11-ol.2. Besides the diterpene alcohols and abietinal, the high-boiling oxygen containing fraction of the cedar resin contains D--cadinol C₁₅H₂₆O and a lactone C₁₇H₂₆O₃.Khimiya Prirodnykh Soedinenii, Vol. 1, No. 4, pp. 250–256, 1965     

Lactones ofFerula gigantea

The following substances have been isolated from an acetone extract ofFerula gigantea B. Fedtsch.: a coumarin — umbelliferone, C₉H₆O₂, mp 230–233°C; and sesquiterpene lactones — talassin A, C₂₅H₃₀O₇, mp 188–191°C; malaphyllinin, C₂₄H₂₄O₇, mp 231–235°C; malaphyll, C₂₉H₃₂O₉, mp 212–213°C; and malaphyllin, C₂₆H₂₈O₉, mp 216–218°C. Structures have been proposed for three new sesquiterpene lactones on the basis of an analysis of their spectral characteristics.All-Union Scientific-Research Institute of Medicinal Plants, Moscow. M. V. Lomonosov Moscow State University, Botanical Garden, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 490–495, July–August, 1979.     

Theoretical study of polyoxide clusters B20O30, Al20O30, V20O50, Si20O30H20, and Si20O30F20

The structural, electronic, and vibrational characteristics and energies of the isolated polyoxide clusters B₂₀O₃₀, Al₂₀O₃₀, V₂₀O₅₀, Si₂₀O₃₀H₂₀, and Si₂₀O₃₀F₂₀ and their complexes with the H⁻ ion and ammonia complexes Al₂₀O₃₀ · nNH₃ have been calculated by the density functional theory B3LYP method with different basis sets. The computation results show that the symmetric closo structure I _h with oxygen bridges located above the centers of the faces of an empty [M₂₀] dodecahedron is more favorable for V₂₀O₅₀, Si₂₀O₃₀H₂₀, and Si₂₀O₃₀F₂₀. For B₂₀O₃₀, the cage closo isomer is also more favorable than the other isomers, but its structure is severely distorted as compared to a dodecahedron and has a symmetry close to C ₃ . For Al₂₀O₃₀, the I _h structure corresponds to a high-lying local minimum of the potential energy surface. For Al₂₀O₃₀, a set of unusual puckshaped isomers of symmetry C _i , with different numbers of four-coordinate atoms ^IVAl and three-coordinate atoms ^IIIO, was localized; these structures are more than 90 kcal/mol more favorable than the dodecahedron I _h . The most favorable isomer of Al₂₀O₃₀ contains twelve four-coordinate atoms ^IVAl and four five-coordinate atoms ^VAl. The energies of dissociation of the most favorable M₂₀O₃₀ clusters into the M₂O₃ (C _2v ) and M₄O₆ (T _d ) fragments and, in the case of Al₂₀O₃₀, also into the Al₈O₁₂ (O _h ) and Al₁₂O₁₈ (D _3d ) fragments, have been estimated. The conclusion has been drawn that these clusters can, in principle, exist and can be experimentally detected in the isolated state. Analogous calculations have been performed for ammonia complexes Al₂₀O₃₀ · nNH₃ with n varying from 1 to 20. The effect of solvation on the relative stability of the dodecahedral and puckshaped isomers of the Al₂₀O₃₀ cluster is observed. The isomers with ammonia molecules in their first coordination sphere become much closer to one another on the energy scale; however, the dodecahedron remains a considerably less favorable intermediate. Original Russian Text ? O.P. Charkin, N.M. Klimenko, D.O. Charkin, 2008, published in Zhurnal Neorganicheskoi Khimii, 2008, Vol. 53, No. 4, pp. 624–635.     

The Crystal and Molecular Structures of Two Acid-Catalysed Rearrangement Products of Taxochinon

The structures of two acid catalysed rearrangement products of taxochinone ( 1 ) have been determined by X-ray analysis. One of the products turned out to be a 20 (10→9) abeo-abietane ( 2 ), the other an optically inactive phenalenone ( 3 ). Crystals of the former compound, C₂₀H₂₆O₃, belong to space group P2₁2₁2₁ with four molecules per cell and the structure was refined with 879 significant reflexions to R = 0.032. Crystals of the latter compound, C₂₀H₂₂O₂, belong to space group P2₁/c with 12 molecules per cell and the structure was refined with 1823 significant reflexions to R = 0.058.     

(1R,2R)‐1,2‐Di­phenyl‐1,2‐bis(8‐quinoline­sulfonyl­amino)ethyl­enedi­amine–acetone (1/1)

The crystal structure of the new chiral complex (1R,2R)‐1,2‐di­phenyl‐1,2‐bis(8‐quinoline­sulfonyl­amino)‐ ethyl­enedi­amine–acetone (1/1), C₃₂H₂₆N₄O₄S₂^.C₃H₆O, is reported. The conformation of the C₃₂H₂₆N₄O₄S₂ (BQSDA) mol­ecule is determined by a bifurcated N—H?N hydrogen‐bond system. The acetone of solvation is linked to the BQSDA mol­ecule by an N—H?O hydrogen bond.     

Three related benzoannelated diazapolyether macrocycles: effects of macrocycle ring size and position of benzo groups on hydrogen bonding of the amine H atoms

The benzoannelated diazapolyether macrocycles 6,7,9,10,17,18‐hexahydro‐5H,11H‐8,16,19‐trioxa‐5,11‐diazadibenzo[a,g]cyclopentadecene, C₁₈H₂₂N₂O₃, (I), 6,7,9,10,12,13,20,21‐octahydro‐5H,14H‐8,11,19,22‐tetraoxa‐5,14‐diazadibenzo[a,g]cyclooctadecene, C₂₀H₂₆N₂O₄, (II), and 6,7,9,10,17,18,20,21‐octahydro‐16H,22H‐5,8,11,19‐tetraoxa‐16,22‐diazadibenzo[a,j]cyclooctadecene 0.3‐hydrate, C₂₀H₂₆N₂O₄·0.304H₂O, (III), show different patterns of hydrogen bonding. In (I), the amine H atoms participate only in intramolecular hydrogen bonds with ether O atoms. In (II), the amine H atoms form intramolecular hydrogen bonds with the phenoxy ether O atoms and intermolecular hydrogen bonds with alkyl ether O atoms in an adjacent molecule, forming a chain linking the macrocycles together via an R₂²(10) motif. Molecules of (II) were found on a crystallographic twofold axis. In (III), the amine H atoms participate in a hydrogen‐bond network with adjacent ether O atoms and with a water molecule [having a partial occupancy of 0.304 (6)] that links the molecules together via a C₂²(7) motif.     

Evaluation of AM1-calculated radical cation ion-neutral complexes

AM1 semiempirical molecular orbital calculations are reported for 20 ion-neutral complexes, including hydrogen-bonded complexes, presumably involved in the gas-phase unimolecular decomposition of simple organic radical cations. The systems investigated are [C₂H₄O₂]^˙+, [C₂H₅NO]^˙+, [C₂H₆O]^˙+, [C₂H₆O₂]^˙+, [C₃H₆O]^˙+, [C₃H₆O₂]^˙+, [C₃H₈O]^˙+, and [C₃H₈O₂]^˙+. The AM1 results are compared with ab initio molecular orbital calculations at different levels of theory up to MP3/6-31G(d, p)//SCF/6-31G(d) + ZPVE and the available experimental data. AM1 fails to predict some local minima and the equilibrium geometries calculated for several complexes are found to be qualitatively different from those predicted by the ab initio calculations. However, reasonable agreement is generally found for the stabilization energies of the complexes toward dissociation into their loosely bound components. © John Wiley & Sons, Inc.     

The Catalytic Dehydrogenation of c2h6 to c2h4 under non-Oxidative Conditions over the 6cr/g-al2o3Catalyst

In the present paper, the catalytic dehydrogenation of C₂H₆ to C₂H₄ under non-oxidative conditions was investigated in a fixed-bed micro-reactor under ambient pressure at 823 - 923 K. The 6Cr/g-Al₂O₃ catalyst was found to be the best catalyst among the g-Al₂O₃, SiO₂, MCM41, MgO and Si-2 supported chromium oxide catalysts. The features of the 6Cr/g-Al₂O₃ catalyst for the reaction could be listed as follows: (1) At 823 - 923 K, the C₂H₄ selectivity of 92.5-78.6% at a C₂H₆ conversion of 9.5-29.8% could be obtained. (2) The catalyst had the good regeneration performance, i.e., could be regenerated by air repeatedly. (3) The main products were C₂H₄, CH₄, H₂ and coke. No carbon oxides were identified.     

Comparative characterization of the coumarin composition ofSeseli campestre growing in Moldavia and in the Caucasus

The results are given of the identification of (?)-trans-khellactone and its 4′-methyl ether and (?)-3′(S), 4′(S)-trans-3′-senecioyloxy-4′-angeloyloxy-3′,4′-dihydroseselin and of the establishment of the structure of three new khellactone derivatives — campestrol (VII), C₁₉H₂₂O₆, [α] _D ²⁰ + 32° (c 7.8; chloroform), campestrinol (X), C₂₄H₂₆O₇, mp 116–118°C, and campestrinoside (I), C₂₀H₂₄O₁₀, mp 172–173°C, [α]_D ?272.5° (c 4.7; ethanol). It has been shown on the basis of chemical and spectral characteristics that campesol, earlier described as a new substance, is a mixture of two isomeric compounds — 4′-hydroxy-3′-senecioyloxy-3′,4′-dihydroseselin and 3′-angeloyloxy-4′-hydroxy-3′,4′-dihydroseselin.     

Pentazol‐Derivate und daraus entstehende Azide: [O3S—p‐C6H4—N5]— und [O3S—p‐C6H4—N3]— als Kalium‐Kronenether‐Salze

Pentazole Derivates and Azides Formed from them: Potassium‐Crown‐Ether Salts of [O₃S—p‐C₆H₄—N₅]^— and [O₃S—p‐C₆H₄—N₃]^{— —}O₃S—p‐C₆H₄—N₂⁺ was reacted with sodium azide at —50 °C in methanol, yielding a mixture of 4‐pentazolylbenzenesulfonate and 4‐azidobenzenesulfonate (amount‐of‐substance ratio 27:73 according to NMR). By addition of KOH in methanol at —50 °C a mixture of the potassium salts K[O₃S—p‐C₆H₄—N₅] and K[O₃S—p‐C₆H₄—N₃] was precipitated (ratio 60:40). A solution of this mixture along with 18‐crown‐6 in tetrahydrofurane yielded the crystalline pentazole derivate [THF‐K‐18‐crown‐6][O₃S—p‐C₆H₄—N₅]·THF by addition of petrol ether at —70 °C. From the same solution upon evaporation and redissolution in THF/petrol ether the crystalline azide [THF‐K‐18‐crown‐6][O₃S—p‐C₆H₄—N₃]·THF was obtained. A solution of the latter in chloroform/toluene under air yielded [K‐18‐crown‐6][O₃S—p‐C₆H₄—N₃]·1/3H₂O. According to their X‐ray crystal structure determinations [THF‐K‐18‐crown‐6][O₃S—p‐C₆H₄—N₅]·THF and [THF‐K‐18‐crown‐6][O₃S—p‐C₆H₄—N₃]·THF have the same kind of crystal packing. Differences worth mentioning exist only for the atomic positions of the pentazole ring as compared to the azido group and for one THF molecule which is coordinated to the potassium ion; different orientations of the THF molecule take account for the different space requirements of the N₅ and the N₃ group. In [K‐18‐crown‐6][O₃S—p‐C₆H₄—N₃]·1/3H₂O there exists one unit consisting of one [K‐18‐crown‐6]⁺ and one [O₃S‐C₆H₄—N₃]^— ion and another unit consisting of two [O₃S‐C₆H₄—N₃]^— ions joined via two [K‐18‐crown‐6]⁺ ions and one water molecule. The rate constants for the decomposition [O₃S‐C₆H₄—N₅]^— → [O₃S‐C₆H₄—N₃]^— + N₂ in methanol were determined at 0 °C and —20 °C.     

Surface Nanostructures Composed of Thiolated Cyclodextrin/Au and Fe Species: Gas‐ and Liquid‐Phase Preparation

Supramolecular surface nanostructures have application potential as functional devices. The complex combination of thiolated cyclodextrin, chemisorbed on an Au surface (Au‐S‐CD), with deposited Fe species is studied by secondary ion mass spectrometry. The Fe species are prepared by pulsed laser ablation in water and thermal effusion in vacuum. Using laser ablation in water, the solution of Fe species is dropped on Au‐S‐CD, where mass peaks at 1227 m/z, 1243 m/z, and 1260 m/z are observed and assigned to C₄₂H₆₈O₃₄SNa‐Fe⁺, C₄₂H₆₈O₃₄SK‐Fe⁺ together with C₄₂H₆₈O₃₄SNa‐FeO⁺, and C₄₂H₆₈O₃₄SK‐FeO⁺, respectively. On the other hand, laser ablation directly linked to the Au‐S‐CD surface results in desorption of CD‐S. Thermal effusion, even with a cooled surface, was negative with respect to the complex observation. Laser ablation results in the formation of a supramolecular host–guest complex of the form Au‐S‐CD‐Fe, and in the formation of an adduct of the form Au‐S‐CD‐FeO.     

Providing Support in Favor of the Existence of a PdII/PdIV Catalytic Cycle in a Heck‐Type Reaction

The complex [Pd(O,N,C‐L)(OAc)], in which L is a monoanionic pincer ligand derived from 2,6‐diacetylpyridine, reacts with 2‐iodobenzoic acid at room temperature to afford the very stable pair of Pd^IV complexes (OC‐6‐54)‐ and (OC‐6‐26)‐[Pd(O,N,C‐L)(O,C‐C₆H₄CO₂‐2)I] (1.5:1 molar ratio, at ?55 °C). These complexes and the Pd^II species [Pd(O,N,C‐L)(OX)] and [Pd(O,N,C‐L′)(NCMe)]ClO₄, (X=MeC(O) or ClO₃, L′=another monoanionic pincer ligand derived from 2,6‐diacetylpyridine), are precatalysts for the arylation of CH₂?CHR (R?CO₂Me, CO₂Et, Ph) using IC₆H₄CO₂H‐2 and AgClO₄. These catalytic reactions have been studied and a tentative mechanism is proposed. The presence of two Pd^IV complexes was detected by ESI(+)‐MS during the catalytic process. All the data obtained strongly support a Pd^II/Pd^IV catalytic cycle.     

Synthesis,Structure and Characterization of Dinuclear Pentacoordinate Molybdenum(V) Complexes with Thiosemicarbazone Ligands

New dinuclear pentacoordinate molybdenum(V) complexes, [Mo₂^VO₃L₂] [L = thiosemicarbazonato ligand: C₆H₄(O)CH:NN:C(S)NHR′ and C₁₀H₆(O)CH:NN:C(S)NHR′; R′ = H, CH₃, C₆H₅) were obtained either by oxygen atom abstraction from Mo^VIO₂L with triphenylphosphine or by using [Mo₂O₃(acac)₄] in the reaction with the corresponding ligands H₂L. Crystal and molecular structure of [Mo₂O₃{C₆H₄(O)CH:NN:C(S)NHC₆H₅}₂] · CH₃CN has been determined by the single‐crystal X‐ray diffraction method.     

Alkaloide aus Evonymus europaea L.

From the seeds of Evonymus europaea L. (Celastraceae) the three previously described alkaloids A, B and C were isolated and their empirical formulae determined by mass spectrometry. Alkaloid B, now named evozine, C₃₂H₃₉NO₁₅ ( 14 ), alkaloid A, now named evorine, C₃₄H₄₁NO₁₆ ( 15 ), and alkaloid C, shown to be identical with Parter's & Libiseller's evonine, C₃₆H₄₃NO₁₇ ( 17 ), are respectively tri-, tetra-, and penta-O-acetyl derivatives of deacetylevonine ( 13 ), C₂₆H₃₃NO₁₂. Vigorous alkaline hydrolysis of the latter yields the previously known evonic acid ( 3 ). Deacetylevonine ( 13 ) is an ester of evonic acid ( 3 ) and a hypothetical polyhydroxy compound C₁₅H₂₄O₁₀ ( 2 ), which is unstable on alkaline hydrolysis. By partial saponification and partial acetylation, these three alkaloids can be converted into each other, at the same time giving rise to a fourth alkaloid D ( 16 ), C₃₄H₄₁NO₁₆, which we name iso-evorine. This had been obtained already by M. Osowiecki (unpublished).     

Eight new crystal structures of 5‐(hydroxymethyl)uracil, 5‐carboxyuracil and 5‐carboxy‐2‐thiouracil: insights into the hydrogen‐bonded networks and the predominant conformations of the C5‐bound residues

In order to examine the preferred hydrogen‐bonding pattern of various uracil derivatives, namely 5‐(hydroxymethyl)uracil, 5‐carboxyuracil and 5‐carboxy‐2‐thiouracil, and for a conformational study, crystallization experiments yielded eight different structures: 5‐(hydroxymethyl)uracil, C₅H₆N₂O₃, (I), 5‐carboxyuracil–N,N‐dimethylformamide (1/1), C₅H₄N₂O₄·C₃H₇NO, (II), 5‐carboxyuracil–dimethyl sulfoxide (1/1), C₅H₄N₂O₄·C₂H₆OS, (III), 5‐carboxyuracil–N,N‐dimethylacetamide (1/1), C₅H₄N₂O₄·C₄H₉NO, (IV), 5‐carboxy‐2‐thiouracil–N,N‐dimethylformamide (1/1), C₅H₄N₂O₃S·C₃H₇NO, (V), 5‐carboxy‐2‐thiouracil–dimethyl sulfoxide (1/1), C₅H₄N₂O₃S·C₂H₆OS, (VI), 5‐carboxy‐2‐thiouracil–1,4‐dioxane (2/3), 2C₅H₄N₂O₃S·3C₆H₁₂O₃, (VII), and 5‐carboxy‐2‐thiouracil, C₁₀H₈N₄O₆S₂, (VIII). While the six solvated structures, i.e. (II)–(VII), contain intramolecular S(6) O—H…O hydrogen‐bond motifs between the carboxy and carbonyl groups, the usually favoured R₂²(8) pattern between two carboxy groups is formed in the solvent‐free structure, i.e. (VIII). Further R₂²(8) hydrogen‐bond motifs involving either two N—H…O or two N—H…S hydrogen bonds were observed in three crystal structures, namely (I), (IV) and (VIII). In all eight structures, the residue at the ring 5‐position shows a coplanar arrangement with respect to the pyrimidine ring which is in agreement with a search of the Cambridge Structural Database for six‐membered cyclic compounds containing a carboxy group. The search confirmed that coplanarity between the carboxy group and the cyclic residue is strongly favoured.     

Effect of conversion of NO2 into no on the catalytic reduction of NO2 with C3H6 in excess O2

During the reduction of NO₂ by C₃H₆ in O₂ over alumina-supported Au, Rh and Pt it was found that three parallel reactions take place,i.e., reduction of NO₂ to N₂ and N₂O, partial decomposition of NO₂ to NO and oxidation of C₃H₆ to CO and CO₂. In the absence of C₃H₆, the NO₂→NO+O₂ reaction reaches a fast equilibrium on Rh and Pt but not on Au and γ-Al₂O₃. Addition of C₃H₆ to the NO₂+O₂ mixture leads to the formation of NO above equilibrium conversion levels.     

Diterpenoids fromMarrubium peregrinum. I

Summary Two new diterpenoids have been isolated fromMarrubium peregrinum L.: a bicyclic diol C₂₀H₃₆O₂, peregrinol — and a hydroxyketolactone C₂₀H₂₅O₅, peregrinin. A substance C₁₉H₁₈O₆ has been obtained as a by-product.Khimiya Prirodnykh Soedinenii, Vol. 2, No. 4, pp. 249–251, 1966