bluuebunny/crossref_metadata_2025 huggingface dataset:
Etudes sur les composés organométalliques XIV. Réactivité du tétrabenzyltitane (lère communication)
Authors: Causse Jacques , Tabacchi Raffaele , Jacot‐Guillarmod André
Published: December 2004

The reactivity of tetrabenzyltitanium with acetone, benzophenone, butanal, acetyl chloride, butyl acetate, ethyl chloroformate, benzonitrile, propylene oxide, carbon dioxide has been investigated.

The results show that tetrabenzyltitanium reacts like benzylmagnesium‐chloride. The socalled ‘anomalous reaction’ is observed. Benzonitrile, propylene oxide and carbon dioxide, on the other hand, do not react.
Präparative Darstellung von μ‐Disauerstoff‐bis‐kobalt(II)‐Chelaten
Authors: Zehnder M. , Fallab S.
Published: December 2004

Binuclear cobalt chelates with O2 as bridging ligand have been prepared, using ethylenediamine, triethylenetetramine, tetraethylenepentamine and tris‐(2‐aminoethyl)‐amine as chelating agents and SCN− and ClO4− as anions. They form well characterized crystals which give off molecular oxygen spontaneously in acid solution and, except in the case of the cobalt tetra‐ethylenepentamine chelate, reveal the general composition [(Z)Co · μ(O2, OH) · Co(Z)]X3, where Z represents the polydentate complexing agents and X the anion. In the presence of ammonia different complexes are produced, in which NH3 occupies one coordination site of each cobalt, replacing the hydroxo bridge.
Über die Ausdrucksweisen der Konzentration des Wasserdampfes bei Wasserdampf‐Sorptionsmessungen
Authors: Gál S.
Published: December 2004

The definitions of the partial pressure of water vapor, the activity of water, the relative humidity and the partial relative density of water vapor are reproduced and their functional relationships are given. The numerical values of these variables between −10°C and +100°C and at total pressures between the pressure of the own vapor and 10,133 mbar have been computed and tabulated (tables available in form of microfilm or xerox‐copies from Buchhandlung Herbert Lang & Cie, Münzgraben 2, CH‐3000 Bern). The limits of indistinct use of these variables are discussed.
Die Photochemie von Diazo‐dibenzoylmethan Eine wellenlängen‐ und temperaturabhängige Photoreaktion
Authors: Baumann N.
Published: December 2004

Diazo‐dibenzoylmethane I undergoes two primary photochemical processes leading to α‐phenyl‐α‐benzoyl‐methane II and dibenzoylmethane III. The formation of II is related to the lowest excited singlet state of I and the formation of III is related to the lowest excited triplet state of I. The quantum yields of both processes (ΦII, ΦIII) are strongly wavelength dependent. It is unambiguously demonstrated, that the population of the two excited states depends on the energy of the exciting light, thus causing a wavelength effect. There is shown to be an activation barrier controlling the rate of intersystem crossing from the S1 to the T1 level of I.
Triplet‐Triplet Absorption Spectra of Aromatic Hydrocarbons: I. Naphthalene
Authors: Wild Urs P. , Känzig Herbert , Ranalder Urs B.
Published: December 2004

The difference between the triplet‐triplet and singlet‐singlet absorption spectrum of naphthalene has been measured at 90°K using a newly developed computer controlled spectrograph. Good spectral resolution has been obtained and a strong band was found in the ultraviolet region. Recent calculations are compared with the triplet‐triplet spectrum of naphthalene.
Heterotricyclodecane XI, Sulfoxide und Sulfone von 2‐Oxa‐7‐thia‐isotwistan und 2‐Oxa‐7‐thia‐twistan sowie Derivaten
Authors: Wigger N. , Stücheli N. , Szezepanski H. , Ganter C.
Published: December 2004

The synthesis of sulfoxides and sulfones of 2‐oxa‐7‐thia‐isotwistane (24) and 2‐oxa‐7‐thia‐twistane (35) as well as of several of their derivatives is described. endo‐2‐Hydroxy‐9‐thiabicyclo[3.3.1]non‐6‐ene (5) was used as starting material.

During the course of the reactions special attention was given to intramolecular hydroxy‐mercuration and jododemercuration reactions, spectroscopic features, molecular rearrangements and stereospecificity of oxidations of sulfides to sulfoxides.
Nucleophilic Substitution in Dipolar Aprotic Solvents: Hexamethylphosphoric triamide
Authors: Müller Paul , Siegfried Bernard
Published: December 2004

The rate of the reaction between ethyl tosylate and chloride as well as bromide ion has been measured in hexamethylphosphoric triamide in the presence of several counterions. Rate constants for the free ions at 25.0° are 14.4 mole−1 for chloride and 2.0 mole−1min−1 for bromide, both independent of the cation used. The equilibrium constants for ion pair dissociation of lithium‐, ammonium‐ and tetra‐n‐butylammonium chloride are 3.97 × 10−2, 1.52 × 10−3 and 6.36 × 10−3 mole, and for the corresponding bromides 3.30 × 10−2, 9.65 × 10−3, and 9.62 × 10−3 mole.
Tubotaiwin‐N‐oxid aus der Wurzelrinde von Conopharyngia johnstoni Stapf. 148. Mitteilung über Alkaloide
Authors: Pinar M. , Renner U. , Hesse M. , Schmid H.
Published: December 2004

From the root bark of Conopharyngia johnstonii Stapf (Apocynaceae) the hitherto unknown tubotaiwine‐N‐oxide (2) together with tubotaiwine (1) were isolated and characterized.
Oxydationsprodukte von 6‐Hydroxy‐dopamin
Authors: Wehrli P. A. , Pigott F. , Fischer U. , Kaiser A.
Published: December 2004

6‐Hydroxy‐dopamin (2, 4, 5‐Trihydroxyphenäthylamin) (1) wird durch Sauerstoff oder durch Frémy‐Salz nahezu quantitativ zu einem dunkelroten Chinon oxydiert, das sich in gelbe Hydrohalogenide überführen lässt. Das wahrscheinlich als Zwitterion 2 vorliegende Chinon ist in kristalliner Form stabil. In schwach alkalischer Lösung lagert es sich in 5, 6‐Dihydroxy‐indol (4) um. Alkalische Reduktion führt u.a. zu 5, 6‐Dihydroxy‐indolin, während unterhalb pH 7 hauptsächlich 6‐Hydroxy‐dopamin (1) zurückgebildet wird.
Metastabile, basische Bleisalze des 2,4,6‐Trinitroresorcins
Authors: Durtschi André , Rauber Walter
Published: December 2004

Beim Zusammengiessen einer alkalischen Lösung von 2,4,6‐Trinitro‐resorcin mit einer Bleilösung entstehen zwei metastabile Bodenkörper, und zwar bei pH 5–9 eine neue Modifikation (I) des bereits bekannten Pb2(OH)2Tric (Tric = Anion des 2,4,6‐Trinitro‐ resorcins), und bei pH 10–12,5 Pb7(OH)10Tric2 (II). I wandelt sich in die bekannte stabile Form um, II reagiert bis pH 11 zu Pb5(OH)6Tric2, darüber zu Pb13O7(OH)10Tric2.
Chemische und pharmakologische Studien über Derivate des Benzo[de]chinolins (I). 8. Mitteilung über natürliche und synthetische Isochinolinderivate
Authors: Schneider Fernand , Gerold M. , Bernauer Karl
Published: December 2004

Synthesis and cardiovascular evaluation of ketones 10, 11 and 12 and of their derivatives 14 to 35 are described.
Cycloaddition von Heterocumulenen an CN‐Bindungssysteme. 1. Mitteilung. Perhydro‐s‐triazindione und Perhydro‐s‐triazinyl‐harnstoffe aus N,N,N′‐trisubstituieten Formamidinen und Isocyanaten
Authors: Seckinger Karl
Published: December 2004

The addition of methyl isocyanate to N,N‐dimethyl‐N′‐arylformamidines 4d–4r leads to the perhydro‐s‐triazine‐diones 5d–5o and to the s‐triazinylureas 10a–10k. The mechanism of formation is discussed.

The addition of the arylisocyanates 18a–18p to the N,N,N′‐trialkylformamidines 9 and 27a–27i furnishes the expected 1,4‐cycloaddition products 26 and 27 in good yields. The N,N‐di‐isopropyl‐N′‐alkylformamidines 27j–271, however, do not undergo 1,4‐dipolar cycloadditions and react with the arylisocyanate 18b to yield the alkyl isocyanates 31a–31c and N,N‐diisopropyl‐N′‐(p‐chlorphenyl)‐formamidine 32 exclusively.
Die Photoelektronen‐Spektren methyl‐substituierter Acetylene
Authors: Brogli Franz , Heilbronner Edgar , Hornung Volker , Kloster‐Jensen Else
Published: December 2004

The PE.‐spectra of triacetylene 1 (3), methyldiacetylene 2 (2), dimethylacetylene 3 (1) and dimethyldiacetylene 3 (2) have been recorded. The π‐ionization potentials of the unsubstituted acetylenes can be parametrized in terms of a LCBO‐model.
Reduction of Tosylamino Acids and Related Compounds with Sodium in Liquid Ammonia; stoichiometry and products
Authors: Rudinger Josef , Van Den Brink‐Zimmermannová Helena Maassen
Published: December 2004

Using an extraction procedure which permits determination of end‐points, the reduction of a number of tosylamino acids, their derivatives, and model compounds with sodium in liquid ammonia has been investigated. When the molecule contains a single acidic group in addition to the tosylamino group (as in the case of the simple mono‐tosylamino monocarboxylic acids) reduction proceeds with the consumption of 2 g‐at. Na per tosyl group and the formation of toluene‐4‐sulphinic acid. If the number of acidic groups in the products is insufficient to accommodate the number of electrons consumed in the reduction, the reduction of ionisable tosylamino groups is incomplete unless an acid is added. If the number of acidic groups is higher, or excess acid is added, the sulphur‐containing products include thiocresol and sulphite. This last reaction course is also observed whenever calcium is used in place of sodium. A partial interpretation of the results is offered.
Der Mechanismus der Umlagerung substituierter Aminoacrylderivate
Authors: Niederhauser Andreas , Bart Gerhard , Neuenschwander Markus
Published: December 2004

Thioacetic acid and dithioacetic acid react with alkynederivatives of the type (CH3)2NCCCOR (1) in the same way as other carboxylic acids: The addition to dimethylaminopropinal (1a) at low temperatures yields, after rearrangement of the very instable primary adducts,Z‐3‐acetoxy‐N,N‐dimethyl‐thioacrylamide (Z‐16) andZ‐3‐thioacetoxy‐N,N‐dimethylthioacrylamide (Z‐17) respectively. The structure of the two compounds can be proved by spectroscopic evidence of16and18, the latter being formed by elimination of thioketene from17. According to the distribution of S‐atoms in16and17, two reaction pathways including 4‐membered rings can be ruled out. Thus the rearrangement of 3‐acyloxy‐N,N‐dimethyl‐acrylamides most probably proceeds by a mechanism including a dipolar six‐membered intermediate.

This mechanism cannot be valid for the rearrangement of the adducts2of hydrohalogen acids, alcohols and amines to the alkyne‐derivatives1. The acid‐catalysed reaction of 3‐chloro‐3‐dimethylamino‐propenal (2, XCl), labelled at position 1 with13C, yields 3‐chloro‐N,N‐dimethyl‐acrylamide (3, XCl), containing the label exclusively at position3. This result supports a mechanism including an immonium‐oxetene21(XCl) as intermediate. ‐ The experiments are in accord with kinetic investigations.
Zur Photochemie von 3,5‐Diaryl‐2‐isoxazolinen. 30. Mitteilung über Photoreaktionen
Authors: Giezendanner Heinz , Rosenkranz Hans Jürgen , Hansen Hans‐Jürgen , Schmid Hans
Published: December 2004

Irradiation of 3,5‐diphenyl‐ or 3‐(p‐tolyl)‐5‐phenyl‐2‐isoxazoline (12 and 13, respectively) in benzene with a high‐pressure mercury lamp yields 4,5‐diphenyl‐ or 4‐(p‐tolyl)‐5‐phenyl‐3‐oxazoline (17 and 19, respectively) and the β‐amino‐chalcones 18 or 20 in addition to benzaldehyde, benzonitrile and p‐tolunitrile, respectively (scheme 6 and ‘Anmerkg.’ p. 2600). The 3‐oxazolines 17 and 19 are formed by route a (scheme 8) via 3‐phenyl‐ or 3‐(p‐tolyl)‐2H‐azirine (23, R = H and CH3, respectively) and their photochemically rearranged successors, the nitrile methylides 24, as intermediates. The discovery of this reaction has served as a basis for the quickly developing photochemistry of 3‐aryl‐2H‐azirines [2] [24].

Photolysis of the 2‐isoxazoline 13 in methanol leads to the formation of a mixture of syn/anti‐p‐tolyl trans‐styryl ketoximes (syn/anti, trans‐30) and anti, cis‐30, 2‐(p‐tolyl)‐quinoline (29), the 4‐hydroxymethylated derivative 32 of the latter (in small amounts), besides the β‐aminochalcone 20, benzaldehyde, p‐tolualdehyde and p‐tolunitrile (scheme 9). It could be shown that the stereoisomeric ketoximes 30 are photochemically interconvertible (scheme 12) and that at least one mechanism of formation of 2‐(p‐tolyl)‐quinoline (29) is the photo‐induced cyclisation of p‐tolyl‐cis‐styryl ketoximes (cis‐30) (scheme 13). A tentative mechanism for the formation of p‐tolual‐dehyde is given in scheme 10; the crucial step is the protonation of p‐tolunitrile methylide (24, R = CH3) by methanol at the nitrile carbon atom, after which hydrolysis yields the aldehyde.
Photochemisches Verhalten von N‐Acyl‐11‐methyl‐hexahydrocarbazolen
Authors: Winkler‐Lardelli Barbara , Rosenkranz Hans Jürǵen , Hansen Hans‐Jürǵen , Schmid Hans , Blank Bernd , Fischer Hanns
Published: December 2004

The irradiation of N‐acylated 11‐methyl‐1,2,3,4,10,11‐hexahydrocarbazoles (compounds 6–10) and of the 8‐methoxy derivatives 11–13 in hexane solution, with 254 nm light, in the presence of air, leads to 11‐methyl‐2,3,4,11‐tetrahydro‐1 H‐carbazole (2) (table 1) and its 8‐methoxy derivative 21, respectively (scheme 2). Furthermore the 8‐acylated products. 14, 15, 16, 18, are formed in minor amounts by a “photoanilide” rearrangement. Irradiation of the N‐acetyl‐8‐methoxy‐indoline 12 gives in addition (by elimination of the 8‐methoxy group) the 8‐acetyl‐indoline 14 and, by coupling, the dimeric compound 23 (schemes 2 and 4). Irradiation of the N‐formyl‐indoline 6 yields, besides the indolenine 2 the indoline 1 (table 1). The mechanism of the anaerobic part of these photoreactions were investigated by CIDNP experiments.

It is possible to convert directly indoline 1 to the indolenine 2, in 33% yield, by irradiation at 60° in the presence of oxygen.
Structure of a boron‐free hydrolysis product from Boromycin
Authors: Marsh Wayne , Dunitz Jack D. , White David N. J.
Published: December 2004

The structure of des‐boron‐des‐valine‐boromycin C40H68O14 · H2O (DBDVB), the product obtained by hydrolysis of the antibiotic boromycin C45H74BNO15, has been determined by X‐ray analysis. The molecule is remarkably similar in constitution, configuration and even in conformation to those of boromycin and des‐valine‐boromycin determined previously [2], showing that the overall molecular shape is retained on removal of the spiro boron atom.
Über die absolute Konfiguration der Cantharsäure und des Palasonins
Authors: Peter Martin G. , Snatzke Günther , Snatzke Feliksa , Nagarajan K. N. , Schmid Hans
Published: December 2004

The absolute configurations of (+)‐cantharic acid, a chiral derivative of the achiral insect defensive substance cantharidin (1), and of palasonin, a lower homologue of 1 occurring in the plant Butea frondosa, were shown to be represented by formulas 2 and 3, respectively (scheme 1). These results were obtained by application of the Horeau method (table 1) on the (+)‐cantharic acid derivatives (+)‐5, (−)‐7, and (−) 11 (scheme 2), and the palasonin derivatives (+)‐29 and (+)‐30 (scheme 4), as well as by comparison of the chiroptical properties (tables 2 and 3) of a number of derivatives, prepared from either cantharic acid or palasonin. – Attempts to incorporate various radioactively labelled precursors into palasonin (3), using young and adult plants, have been so far unsuccessful.
Quantitative Bestimmung, Charakterisierung und Stabilität von Magnesium 5‐Methyltetrahydrofolat
Authors: Conti Josef , Suter Hans , Widler Rita
Published: December 2004

Die Eigenschaften des Magnesiumsalzes der 5‐Methyltetrahydrofolsäure und eine spezifische Methode zu seiner quantitativen Bestimmung werden beschrieben. Die Stabilitäten der Na‐, Mg‐, Ca‐, Ba‐Salze werden vergleichend untersucht.
Synthese von (±) Seychellen
Authors: Fráter György
Published: December 2004

A four step synthesis of Seychellene (1) is described. Intramolecular Diels‐Alder reaction of dienon 2 furnished the tricyclic ketones 3 and 4 in good yield. Hydrogenation of 3 gave 5 and 6. The higher reactivity of 6 with methyllithium compared to 5 allowed the selective preparation of 8, which, on subsequent acid‐catalyzed rearrangment afforded Seychellen in 57,5% yield. In an analogues manner epi‐Seychellene was synthetized via the intermediates 5 and 7.
The Thermochemical Kinetics of Retro “‐Ene” Reactions of Molecules with the General Structure (Allyl)XYH in the Gas Phase. 8.. The Thermal Decomposition of Methylallylaniline in the Gas Phase
Authors: Egger Kurt W. , Vitins Peter
Published: December 2004

The thermal decomposition of N‐methyl‐N‐allylaniline in the gas phase over the temperature range 575 to 665 K appears to be a homogeneous radical chain reaction yielding allyl and C6H5NCH3 radicals in the primary step as is indicated by the numerous chain‐terminating radical recombination products and the effect of diluents on the rate constants. From experiments carried out with excess of diluent, first order rate constants which can be identified with the rate determining chain initiating step, were calculated using the internal standard technique and found to fit the Arrhenius relationship \documentclass{article}\pagestyle{empty}\begin{document}$\ log({\rm k}/{\rm s}^{ - 1}) = 13.75 \pm 0.43 - (48.50 \pm 1.23\,{\rm kcal mol}^{{\rm - 1}})/2.303\,{\rm RT} $\end{document}. Although the Arrhenius parameters are slightly low, which is attributed to some loss of substrate by secondary reactions, they are in general agreement with prediction. The relevance of these results to the thermal behavior of allylamines and the nature of six‐center transition states is discussed.
Anil‐Synthese. 10. Mitteilung. Über die Darstellung von Styryl‐Derivaten des Dibenzofurans
Authors: Garmatter Jacques , Siegrist Adolf Emil
Published: December 2004

Schiff'sche Basen des Dibenzofuran‐2‐ bzw. ‐3‐carbaldehydes mit p‐Chloranilin können mit p‐tolyl‐substituierten heterocyclischen und carbocyclischen Aromaten in Gegenwart von Dimethylformamid und Kaliumhydroxid bzw. Kalium‐t‐butylat in die entsprechenden Styryl‐Derivate übergeführt werden (« Anil‐Synthese »).

Die Lage der Absorptions‐ und Fluoreszenz‐Maxima der dargestellten Grundkörper mit dem Dibenzofuran‐3‐yl‐Rest wird mit der analoger Verbindungen mit dem p‐Biphenylyl‐Rest verglichen.
8‐Oxabicyclo[5.1.0]octa‐2,4‐dien, reduktive und säurekatalysierte Ringöffnung
Authors: Schiess Peter , Wisson Markus
Published: December 2004

8‐Oxabicyclo[5.1.0]octa‐2,4‐diene (1) is obtained from cycloheptatriene with commercial 40% peracetic acid. Upon catalytic and LiAlH4 reduction the allylic CO‐bond in 1 is cleaved. Acid catalised hydrolysis leads to a mixture of all six possible isomeric cycloheptadienediols. With BF3 in the absence of water isomerization to 3,5‐cycloptadienone is observed.
SN2 Reactions with Carboxylic Esters. Selective cleavage of methyl esters
Authors: Müller Paul , Siegfried Bernard
Published: December 2004

Sodium cyanide in hexamethylphosphoric triamide selectively cleaves methyl esters in the presence of ethyl esters with yields of ca. 80%. The mechanism of the reaction has been investigated. It consists of nucleophilic displacement by cyanide of the carboxylate ion from the alcohol carbon atom (BAl2 mechanism).
Photoelectron Spectroscopy of peri‐Amino Naphthalenes
Authors: Maier John P.
Published: December 2004

The He I photoelectron spectra of peri‐amino and dimethylamino naphthalenes are presented. The differences in the ionization energies of the π‐bands are interpreted by separation of the perturbation of the amino substituent into an inductive destabilization and conjugative stabilization. This affords the assignment of the photoelectron bands of ionization energies below 11 eV and an estimation of the dihedral angle in the peri‐dimethylamino derivatives. The data on the peri‐amino naphthalenes indicate some angular distortion in contrast to 2‐aminonaphthalene.
Ringschlüsse an Chinonylmethanfarbstoffen und analogen Merocyaninen. 1. Mitteilung. Substituierte Dihydro‐naphtho[1,2‐b]phenazinone als neuer Typ von “percyclischen” Merocyaninen
Authors: Schelz Dieter
Published: December 2004

Substituted dihydro‐naphtho[1,2‐b]phenazinone dyes of unexpected properties were synthesized by cyclization of the corresponding (1‐alkyl‐3‐methyl‐2‐quinoxalinylidenmethyl)‐naphtho‐quinones. The visible and H‐NMR. and some mass spectra of the dyes are discussed.
Crystal Structure of the Orthorhombic Modification of a Mononuclear Peroxotitanium(IV) Dipicolinate
Authors: Manohar H. , Schwarzenbach D.
Published: December 2004

The deep red diaquoperoxotitanium dipicolinate [TiO2(C7H3O4N) (H2O)2]2H2O crystallises in a pleochroic triclinic and a nonpleochroic orthorhombic modification. The structure of the former has been reported earlier. The structure of the latter, described in this paper, has been determined from X‐ray diffractometer data and refined to R = 0.034. In both forms the complex occurs as the free acid, but the modes of packing are completely different. Bond lengths and angles agree closely. As in the other peroxotitanium(IV) chelate structures so far determined, titanium has an approximately pentagonal bipyramidal coordination with the peroxo group and the chelate ligand occupying equatorial sites and the waters forming the apices. The relationship proposed earlier between the basicity of the ligands and the bond lengths and colours of the related compounds is substantiated. The final difference Fourier maps obtained with normal and modified refinement procedures clearly reveal bonding electron densities. They indicate a pentagonal bipyramidal sp3d3 hybridisation of titanium with bent Ti‐Operoxo bonds, again in agreement with the triclinic form and other peroxotitanium chelates.
Notiz über das natürliche Auftreten von 3‐Phenylisocumarin
Authors: Charubala Ramamurty , Guggisberg Armin , Hesse Manfred , Schmid Hans
Published: December 2004

3‐Phenylisocumarine was isolated for the first time from natural source (leaves of Homalium laurifolium JACQ.).
Limitations of Affinity Chromatography: Solvolytic Detachment of Ligands from Polymeric Supports
Authors: Tesser Godefridus Ignatius , Fisch Hans‐Ulrich , Schwyzer Robert
Published: December 2004

Ligands of the RNH2 type which are covalently bound to agarose, cellulose, or cross‐linked dextranes by the conventional cyanogen bromide method are slowly detached from their supports by solvolytic processes occurring above pH 5 in aqueous surroundings. At pH values between 5 and 10, the free ligands, RNH2, appear in solution. Above about pH 10, the carbamyl derivative of the ligand, RNHCONH2, is the main product. Dilute ammonia releases iminocarbamyl derivatives, RNHC(NH)NH2. The latter type of compound has also been observed in tris(hydroxymethyl)‐aminomethane buffers at pH 8 and 9. Possible reaction mechanisms have been formulated on the basis of the structures suggested by Axén & Ernback for activated and substituted polysaccharides. Ligands attached to polyacrylamide gels (A) through amide bonds to carboxyl groups of the carrier, RNHCO·A, are released at slower rates and invariably as the free, unsubstituted ligand molecules. The release reaction appear to be general and independent of the particular ligand structure. We therefore advise caution with all experiments that can be adversely influenced by the presence of free ligands (e.g. localization of hormone receptors on the cell surface). At pH5, sepharose‐bound 8‐(ϵ‐aminocaproyl‐β‐aminoethylthio)‐adenosine‐3′, 5′‐cyclo‐monophosphate removes cyclic 3′, 5′‐adenosine‐monophosphate‐binding proteins from their solutions, but the corresponding polyacrylamide derivative does not (pH 7).
Biosynthesis of the Cytochalasans. Part III. 13C‐NMR. of cytochalasin B (phomin) and cytochalasin D. Incorporation of [1‐13C]‐ and [2‐13C]‐sodium acetate
Authors: Graf Werner , Robert Jean‐Louis , Vederas John C. , Tamm Christoph , Solomon Philippa H. , Miura Iwao , Nakanishi Koji
Published: December 2004

Sequential single frequency decoupling and partially relaxed Fourier transform (PRFT) are used to assign the natural abundance 13C‐NMR. spectra of cytochalasin B (phomin) (1) and cytochalasin D (2). Cultures of Phoma spec. S 298 were fed [2‐13C]‐sodium acetate, and the distribution of this precursor in cytochalasin B (phomin) (1) was determined by 13C‐NMR. spectroscopy. Likewise, the labelling patterns in cytochalasin D (zygosporin A) (2) from Zygos‐posium masonii could be identified after incorporation of [2‐13C]‐sodium acetate and [l‐13C]‐sodium acetate. The results confirm previous proposals for the biogenesis of the cytochalasans from phenylalanine, methionine, and a C18, or C16, polyketide part.
Photochemische Reaktionen. 78. Mitteilung. Anwendung der π → π*‐induzierten Cyclisierung von α,β‐ungesättigten γ‐Dimethoxymethylketonen auf 19‐Methoxy‐ bzw. 19‐Dimethoxy‐Steroid‐enone und ‐dienone
Authors: Karvaš Milan , Marti Franz , Wehrli Hansuli , Schaffner Kurt , Jeger Oskar
Published: December 2004

Irradiation at 254 nm of 19‐dimethoxyandrost‐4‐en‐17 β‐ol‐3‐one acetate (8) afforded the epimeric cyclization products 9 (yield 20%) and 10 (4%). Similar transformations were also achieved with the analogous dimethoxy‐enone 24 (→ 25, 65%), and‐dienone 30 (→ 31, 72%), and with the methoxy‐enone 33 (→ 34, 30%), and‐dienone 35 (→ 36, 17%).
1‐Fluoro‐benzocyclopropenium Ion from 1,1‐difluoro‐benzocyclopropene
Authors: Burger Ulrich , Müller Paul , Zuidema Laura
Published: December 2004

1,1‐Difluoro‐benzocyclopropene (1) ionizes in fluorosulphonic acid to yield the cation 2, which is stable at − 50° for several hours. Upon quenching with water 2 affords benzoic acid.
Hormone‐Receptor Interactions. Demonstration of Two Message Sequences (Active Sites) in α‐Melanotropin
Authors: Eberle Alex , Schwyzer Robert
Published: December 2004

The purpose of this investigation was to elucidate the biological significance of the tripeptide sequence 11–13, ‐Lys‐Pro‐Val · NH2 contained in α‐melanocyte‐stimulating hormone. To this end the in vitro melanotropic activities of 21 synthetic peptides related to the hormone were determined and compared with one‐another and with results reported in the literature. The tripeptide amide, H · Lys‐Pro‐Val · NH2, its Nα‐acetylderivative, and ‐weakly, but distinctly‐Nα‐acetyl‐L‐lysine‐amide were found to be hormonally active. The following conclusions were drawn: (1) α‐melanophore‐stimulating hormone possesses two message sequences (active sites), ‐Met‐Glu‐His‐Phe‐Arg‐Trp‐Gly‐, and ‐Lys‐Pro‐Val · NH2 which are capable of independently triggering the hormone receptor responsible for melanin dispersion. (2) In correct covalent combination, the two message sequences act in a ‘cooperative’ manner to potentiate their activities on the receptors. (3) ‐Lys‐Pro‐Val‐ is an address sequence in adrenocorticotropic hormone and a message sequence in α‐melanocyte‐stimulating hormone. This implies that the two receptors (adrenal and melanocyte), albeit recognizing ‐Met‐Glu‐His‐Phe‐Arg‐Trp‐Gly‐ as stimulus, differ fundamentally in their response to ‐Lys‐Pro‐Val‐.
Comments on the Interpretation of NMR. Parameters in some platinum‐olefin complexes
Authors: Pregosin Paul S. , Venanzi L. M.
Published: December 2004

13C and 195Pt‐NMR. parameters for the complexes trans‐[PtCl2(C5H10N)‐(CH3CHCHCH3)] are presented. It is suggested that conclusions, concerning metal olefin bond strengths, drawn from NMR. studies of nuclei not directly involved in the bonding can be misleading.
Total Synthesis of Indole and Dihydroindole Alkaloids. VIII. Studies on the synthesis of bisindole alkaloids in the vinblastine‐vincristine series. The chloroindolenine approach
Authors: Kutney James P. , Beck John , Bylsma Feike , Cook James , Cretney Walter J. , Fuji Kaoru , Imhof René , Treasurywala Adi M.
Published: December 2004

Studies on the syntheses of 18′‐epi‐4′‐deoxo‐4′‐epivinblastine (IX, R = CO2CH3; R1 = H), 18′‐decarbomethoxy‐18′‐epi‐4′‐deoxo‐4′‐epivinblastine (IX, R = R1 = H) and related analogues are described. The synthetic method employs a coupling reaction involving chloroindolenine derivatives of the cleavamine series (for example, III) with vindoline (V) under acidic conditions. The complete structures, including absolute configuration, of the resulting dimers are established by a combination of chemical and spectroscopic techniques, including X‐ray analysis.
Ylides du soufre dérivés de sucres Communication préliminaire
Authors: Tronchet Jean M. J. , Eder Hansjörg
Published: December 2004

S‐Methylation of 6‐S‐benzyl‐6‐deoxy‐1,2‐O‐isopropylidene‐3‐O‐methyl‐α‐D‐xylo‐6‐thiohexofuranos‐5‐ulose (1) gave the expected sulfonium salt 2 which on alcaline treatment yielded the stable sulfur ylide 3. This compound constitutes an useful synthetic intermediate in carbohydrate chemistry. On heating in 1,2‐dimethoxyethane, it underwent a Stevens rearrangement which led to an extension of the carbon chain of the sugar and, reacted with Michael acceptors, it gave cyclopropanation reactions.
Regiospecific Intramolecular Aldol Condensation Induced by Conjugate Addition of lithium dimethylcuprate to ζ‐Oxo‐α, β‐enones preliminary communication [1]
Authors: Näf Ferdinand , Decorzant René , Thommen Walter
Published: December 2004

ζ‐Oxo‐α, β‐enones react with lithium dimethylcuprate to give cyclic aldols such as hydroxydecalone 1 and hydroxyspiro[4.5]decanone 2 in a regio‐ and stereospecific manner. This new reaction, a combination of conjugate methyl addition to α, β‐enones with directed intramolecular aldolisation, is suggested to proceed via either enoate anions, such as 8 and 11, or radical anions, such as 9 → 10 and 12 → 13, as intermediates.
Weitreichende Kernspin‐Kopplungen in 2‐Fluorbenzamiden II. [15N]‐2‐Fluorbenzamid
Authors: Fritz Hans , Winkler Tammo , Küng Werner
Published: December 2004

Large ‘through space’ hydrogen‐fluorine and 15N, F‐couplings have been observed in [15N]‐2‐fluorbenzamide. The nuclear spin information is transmitted via the hydrogen bond between fluorine and the trans‐NH‐proton of the amide group, as shown by the solvent dependence of the couplings.
7. Azidiniumsalze. 19. Mitteilung [1]. Einführung der Diazogruppe in reaktive Methylenverbindungen mit Azidiniumsalzen
Authors: Balli Heinz , Löw Richard , Müller Volkmar , Rempfler Hermann , Sezen‐Gezgin Ayten
Published: December 2004

Diazo‐Group Transfer to Active Methylene Compounds Using Azidinium Salts

Die Synthese von Diazoverbindungen durch Diazogruppenübertragungen auf durch Carbonyl‐, Cyan‐ und Nitro‐Gruppen aktivierte Methylenverbindungen mit den Azidiniumsalzen 2‐Azido‐3‐äthyl‐benzthiazolium‐tetrafluoroborat und 1‐Äthyl‐2‐azido‐pyridinium‐tetrafluoroborat wird beschrieben.
9. Azidiniumsalze. 21. Mitteilung [1]. Einführung der Diazogruppe in Amino‐arene und Amino‐hetarene mit Azidiniumsalzen: Synthese kondensierter ν‐Triazole
Authors: Balli Heinz , Felder Louis
Published: December 2004

Diazo‐Group Transfer to Amino‐arenes and Amino‐hetarenes Using Azidinium Salts: Synthesis of 1, 2, 3‐Triazoles

Das Azidiniumsalz 2‐Azido‐3‐äthyl‐benzthiazolium‐tetrafluoroborat (1) lässt sich als Diazogruppenüberträger auf Amino‐arene und Amino‐hetarene einsetzen. Die primär entstandenen Diazoniumsalze cyclisieren sich zu kondensierten ν‐Triazolen bzw. kuppeln mit den Edukten zu o, o′‐Diamino‐azofarbstoffen.
Zur Imidazolbildung aus 2H‐Azirinen bzw. Vinylaziden und Nitrilen unter Säurekatalyse
Authors: Bader Heinz , Hansen Hans‐Jürgen
Published: December 2004

Acid‐Catalysed Formation of Imidazoles from 2H‐Azirines or Vinylazides and Nitriles

The reaction of 2H‐azirines with nitriles in the presence of boron trifluoride etherate to yield the corresponding imidazoles is described. 2,3‐Diphenyl‐2H‐azirine (10) gives 2‐substituted 4,5‐diphenyl imidazoles in moderate bis good yields (seeTable 1). The reaction of10with acrylonitrile only leads to the formation of 4,5‐diphenyl‐2‐vinylimidazole (17). No products resulting from an addition to the C,C double bond are observed. 2H‐Azirine10and ethyl cyanoacetate yield the expected imidazole18(30%) but also 2‐cyanomethyl‐4,5‐diphenyloxazole (20; 7%) (seeScheme 4). The yield of imidazole formation mainly depends on the substituents in position 2 of the 2H‐azirines (seeScheme 6), a change of the substitutents in position 3 having only little influence. The best yields are observed with a phenyl group at C(2) of the 2H‐azirines. These observations are in agreement with the occurrence of 1‐azaallyl cations formed by ring opening of the 2H‐azirines linked to theLewisacid (boron trifluoride). Similar results are obtained with the corresponding vinyl azides with the exception of 1‐azido‐1‐phenylethylene (28). Whereas the corresponding 3‐phenyl‐2H‐azirine (24) gives 2,4‐diphenylimidazole (33;Scheme 6) in the presence of benzonitrile and boron trifluoride etherate, the azide28yields only acetanilide (86%). In the presence of triethyloxonium tetrafluoroborate 2H‐azirines and benzonitrile react to yield the corresponding 1‐ethylimidazoles (seeScheme 9). This again demonstrates that 1‐azaallyl cations must be intermediates which react with the nitrile presumably in aRittertype reaction.13C‐NMR. spectra of 2H‐azirines are also reported(Table 2).
Composants volatils de la «mousse de chêne» (Evernia Prunastri (L.) ACH.) 3e communication
Authors: Gavin José , Nicollier Gilles , Tabacchi Raffaele
Published: December 2004

Volatiles constituents of “Oakmoss”(Evernia Prunastri (L.) ACH.)

The chemical consititution of different fractions of two oakmoss oleoresines were investigated by GC./MS. using SCOT. and capillary columns. Besides many known compounds, over 52 (sesquiterpenes, aliphatic and aromatic hydrocarbons) have not yet been reported as constituents of oakmoss.
3,4‐Dimethoxyfuran: Eigenschaften, Berechnungen und Substitutionsreaktionen
Authors: Iten Peter Xaver , Hofmann Alfred André , Eugster Conrad Hans
Published: December 2004

3,4‐Dimethoxyfuran: Properties, Calculations and some Substitution Reactions

3,4‐Dimethoxyfuran (3,4‐DF) is much more reactive than furan itself. We present experimental details for the synthesis of this useful compound in 50–100 g batches. 3‐4‐Dibenzyloxyfuran has also been prepared. Quantum mechanical calculations by PPP‐and CNDO‐methods analogous to furan itself gave the following information (compared with furan): enhanced negative partial charge at C(2) and C(5), higher acidity at α‐position, a stronger and at the same time inverted dipol moment. In accordance with the calculations, 3,4‐DF can easily be substituted by weak electrophilic reagents, e.g. in a typical Mannich reaction. The bis‐amino compound 8 is produced in good yields. Lithiation by butyl‐Li leads to mono‐ or di‐substituted products. The mono‐ and di‐Li‐3,4‐DF have been used for the preparation of various acylated and alkylated 3,4‐DF derivatives.

By acid hydrolysis of 3,4‐DF crystalline 4‐methoxy‐3 (2H)‐furanone has been prepared.
Kinetics of Extremely Fast Ligand Exchange Reactions with Methylmercury(II)‐complexes of 1‐Methylpyridine‐2‐thione and 1‐Methyl‐quinaldine‐4‐thione: Rate‐Equilibria Correlations
Authors: Erni Isidor , Geier Gerhard
Published: December 2004

Methylmercury(II) transfer from two heterocyclic thiones to a wide variety of other ligands and the reverse reaction have been investigated by the temperature‐jump method. The reactions are almost diffusion controlled, even when the free energy difference is negligible. The only exceptions are reactions to and from hydroxide. They are about hundred times slower than those with other ligands of comparable stability at zero free energy difference. This is in agreement with the behaviour of hydroxide in other methylmercury(II) exchange reactions. They follow an associative reaction mechanism. An empirical correlation of rate‐and equilibrium‐constants for atom transfer reactions is proposed. This equation shows some similarities to that of the Marcus type for atom transfer. However, the proposed equation not only describes reactions governed by an associative mechanism, but also those of dissociative type and cases between the two extremes.
Metal complexes with macrocyclic ligands. XIII. The complexation of Cu2+ with triazacycloalkanes
Authors: Riedo Theodor J. , Kaden Thomas A.
Published: December 2004

The potentiometric study of the complexation of Cu2+ with 1,4,7‐triazacyclononane (1), 1,4,8‐triazacyclodecane (2) 1,5,9‐triazacyclododecane (3) has shown that CuL, CuL2 and (CuLOH)2 are the main species present in solution. Their stabilities (Table 1) and their absorption spectra (Table 2) indicate facial coordination of the cyclic triamines in a distorted octahedral geometry.

The formation and dissociation kinetics have been measured by stopped‐flow techniques. The formation in acetate buffer can be described by the reaction of Cu2+ and CuAcO+ with the monoprotonated species of the ligand. The bimolecular rate constants for these complexations (Table 3) decrease when the ring size increases. In contrast the dissociation induced by acid is only little affected by the ring size. Thus for these complexes the rate of formation and not that of the dissociation determines the overall stability.
The Absolute Configuration of Naturally Occurring (cis‐6‐Methyl‐tetrahydropyran‐2‐yl)acetic Acid, a Constituent of Civet (Viverra civetta)
Authors: Maurer Bruno , Thommen Walter
Published: December 2004

The absolute configuration of the title compound, a minor constituent of civet, is shown to be S,S.
Umlagerungsreaktionen an 11a‐Aminomethyl‐hexahydromorphanthridin‐6(5H)‐onen
Authors: Süess Rudolf
Published: December 2004

Intramolecular transamidation reactions of 11a‐aminomethyl‐hexahydromorphanthridin‐6(5H)‐ones

The methane sulfonic esters, 7A,B of cis‐ and trans‐11a‐hydroxymethyl‐hexahydromorphanthridin‐6(5H)‐one 6A,B rearrange when treated with primary amines forming 2′‐amino‐3,5‐dihydro‐2‐methylspiro [2‐benzazepine‐4(4H), 1′‐cyclohexane]‐1(2H)‐ones 9A,B. The structural change involves an intramolecular trans‐amidation of the intermediates 8A,B. The original morphanthridine skeleton may be recovered by a second rearrangement, with concurrent reduction, induced by lithium aluminium hydride.
Nucleotide. IX. Synthese und Eigenschaften von 1‐(2′‐Desoxy‐D‐ribofuranosyl)‐lumazin‐3′‐monophosphaten
Authors: Charubala Ramamurthy , Pfleiderer Wolfgang
Published: December 2004

Nucleotides. IX. Synthesis and properties of 1‐(2′‐deoxy‐D‐ribofuranosyl)‐lumazin‐3′‐monophosphates

The synthesis of various 1‐(2′‐deoxy‐α‐[and β‐]D‐ribofuranosyl)‐lumazine‐3′‐monophosphates 25‐‐30 starting from the corresponding pteridine nucleosides 1‐‐6 is described. Monomethoxytritylation in 5′‐position to 7‐‐12, phosphorylation by cyanoethylphosphate to 13‐‐18, and deprotection by acid and base treatment afforded the lumazine nucleotides 25‐‐30 in good overall yield. The various reaction products have been characterized by physical means, such as UV. spectra, pK‐values and their chromatographical and electrophoretical behaviour. Enzymatic dephosphorylations by alkaline phosphatase led to the starting material 1‐‐6 with a 3‐‐4 times slower hydrolysis rate in comparison to Tp.
Reaktionen der valenzpolaromeren Ketenform mesoionischer Heterocyclen mit 3‐Dimethylamino‐2H‐azirinen
Authors: Lukáč Josef , Heimgartner Heinz
Published: December 2004

Reactions of valencepolaromeric ketenes of mesoionic heterocyles with 3‐dimethylamino‐2H‐azirines

Reactions of the 3‐dimethylamino‐2H‐azirines 1a and 1b with the mesoionic oxazole 5 and the mesoionic dithiole 6 in acetonitrile at room temperature yield the 1:1 adducts 11, 12, 19 and 20, respectively (Schemes 5 and 8). These products can be formulated as adducts of the aminoazirines and the ketenes 5a and 6a, which are valence polaromeric forms of the mesoionic heterocycles 5 and 6 (Scheme 2).

The structure of the adducts has been elucidated by spectral data and their comparison with the data of (Z)‐11, the structure of which has been established by X‐ray [19]. Oxidation of the 1:1 adducts with KMnO4 in a two‐phase system yields 4‐dimethylamino‐3‐oxazolin‐2‐ones (cf. Scheme 6) by clevage of the exocyclic C,C‐double bond. A mechanism for the formation of the adducts is given in Scheme 9: Nucleophilic attack of 1 on the ketene leads to a primary adduct of type a, which undergoes clevage of the former N(1), C(2)‐azirine bond to give adducts of type 11 or 19. The N(1), C(2)‐ring opening of 1a in the reaction with ketenes contrasts with the N(1), C(3)‐opening of 1a in the addition with, for instance, isothiocyanates. These different ring openings are explained by the difference in nucleophilicity of the heteroatoms X and Y in a′ (Scheme 10).
Minor and Trace Sterols in Marine Invertebrates. XII. Occurrence of 24 (R + S)‐isopropenylcholesterol, 24 (R + S)‐methylcholesta‐5, 25‐dien‐3β‐ol, and 24 (R + S)‐methylcholesta‐7, 25‐dien‐3β‐ol in the caribbean sponge, Verongia cauliformis
Authors: Kokke W. C. M. C. , Pak C. S. , Fenical William , Djerassi Carl
Published: December 2004

In addition to the two new sterols verongulasterol 11 and 25‐dehydroaplysterol 13 of Verongia cauliformis3), which were reported earlier [2] [3], the minor and trace sterols of this sponge include five new sterols listed in the title (with the exception of the known 24 S‐methyl‐cholesta‐5, 25‐dien‐3β‐ol (codisterol, 1b). The isolation of the 24(R)‐epimer of codisterol is of interest, as this compound is a possibly biosynthetic precursor for aplysterol 12, 25‐dehydroaplysterol 13, and verongulasterol 11 (all 24R) which occur in the same sponge [2]. A partial synthesis from fucosterol (4) of 24 (R + S)‐isopropenylcholesterol (9), and of 24‐isopropylcholesterol (10) is described.
Synthesis of 5‐Methyluridine and Its 5′‐Mercapto‐, 2‐Amino‐, and 4′,5′‐Unsaturated Analogues
Authors: Škarié Vinko , Matulié‐Adamié Jasenka
Published: December 2004

The stereospecific cis‐hydroxylation of 1‐(2,3‐dideoxy‐β‐D‐glyceropent‐2‐enofuranosyl)thymine (1) into 1‐β‐D‐ribofuranosylthymine (2) by osmium tetroxide is described. Treatment of 2′,3′‐O, O‐isopropylidene‐5‐methyl‐2,5′‐anhydrouridine (8) with hydrogen sulfide or methanolic ammonia afforded 5′‐deoxy‐2′,3′‐O, O‐isopropylidene‐5′‐mercapto‐5‐methyluridine (9) and 2′,3′‐O, O‐isopropylidene‐5‐methyl‐isocytidine (10), respectively. The action of ethanolic potassium hydroxide on 5′‐deoxy‐5′‐iodo‐2′,3′‐O, O‐isopropylidene‐5‐methyluridine (7) gave rise to the corresponding 1‐(5‐deoxy‐β‐D‐erythropent‐4‐enofuranosyl)5‐methyluracil (13) and 2‐O‐ethyl‐5‐methyluridine (14).

The hydrogenation of 2 and its 2′,3′‐O, O‐isopropylidene derivative 4 over 5% Rh/Al2O3 as catalyst generated diastereoisomers of the corresponding 5‐methyl‐5,6‐dihydrouridine (17 and 18).
Stabilité dans le méthanol et propriétés thermodynamiques de transfert des cryptates de certains cations de transition et de métaux lourds
Authors: Spiess Par Bernard , Arnaud‐Neu Françoise , Schwing‐Weill Marie‐José
Published: December 2004

Stability in Methanol and Thermodynamic Transfer Properties of the Cryptates of some Transition Cations and Heavy Metals

The nature and stability of the macrocyclic and macrobicyclic complexes of Ag+, Cd2+, and Pb2+ (Mn+) with 21, 22, 211, 221 and 222 in anhydrous methanol 0.05M in Et4N+ClO−4, at 25° (see Scheme) have been determined by potentiometry and spectrophotometry. Binuclear complexes M2L2n+ have been observed in all cases, besides the mononuclear MLn+ complexes. The macrobicyclic 1:1 complexes MLn+ exhibit an important ‘cryptate effect’ with Mn+=Ag+, Pb2+ and Cd2+, but not with Cu2+ and Zn2+; their stability is in all cases maximum with 221.

The applicability to our results of the recent extrathermodynamic hypothesis involving MLn+ cryptates is examined.
Die Reaktion von Phthalaldehyden mit 3‐Nitropropionsäureestern. Ein einfacher Zugang zu 3‐Nitro‐2‐naphthoesäuren
Authors: Kienzle Frank
Published: December 2004

The Reaction of Phthalaldehydes with 3‐Nitropropionates. A Simple Route to 3‐Nitro‐2‐naphthoic Acids

3‐Nitro‐propionates condense with phthalaldehydes and related compounds in the presence of a base to give 3‐nitro‐2‐naphthoic acids.
Photochemische Reaktionen. 116. Mitteilung [1]. Notiz zur 1γ, δ*‐induzierten Photospaltung von γ, δ‐Epoxy‐eucarvon
Authors: Tsutsumi Kentaro , Wolf Hans Richard
Published: December 2004

π, π*‐Induced Photocleavage of γ, δ‐Epoxy‐eucarvone.

On 1π, π*‐excitation 1 undergoes cleavage of the C, C‐oxirane bond (1 → c) and isomerizes to the bicyclic dihydrofurane compound 5. In addition, 1 shows photocleavage of the C (γ), O‐oxirane bond (1 → d) and gives the isomers 2, 3, 6, 7 and 8. Furthermore, the cyclohexenone 9 and the cyclohexene‐1, 4‐dione 10 are formed presumably via an intermediate 13, which could also arise from d. Besides these products the compounds 11 and 12 are obtained, which are photoproducts of 2.
Synthesis and Absolute Configuration of Naturally Occurring Dactyloxene‐B and ‐C
Authors: Maurer Bruno , Hauser Arnold , Ohloff Günther
Published: December 2004

Natural (+)‐dactyloxene‐B (12) and ‐C (13) have been synthesized starting from (+)‐trans‐2, 5, 6‐trimethyl‐l‐cyclohexene‐l‐carbaldehyde (1) which is shown to have the (5S, 6R)‐configuration by chemical correlation with (+)‐(2R, 3S, 6S)‐2, 3, 6‐trimethylcyclohexanone. The absolute configurations are therefore (2R, 5R, 9S, 10R) for (+)‐dactyloxene‐B and (2R, 5S, 9S, 10R) for (+)‐dactyloxene‐C.
Synthesis of cannabinoid model compounds. Part 2: (3R, 4R)‐Δ1(6)‐Tetrahydrocannabinol‐5″‐oic acid and 4″(R, S)‐Methyl‐(3R, 4R)‐Δ1(6)‐tetrahydrocannabinol‐5″‐oic Acid
Authors: Franke Ingo , Binder Michael
Published: December 2004

Two novel cannabinoid model compounds, (3R, 4R)‐Δ1(6)‐tetrahydrocannabinol‐5″‐oic acid (22) and 4″(R, S)‐methyl‐(3R, 4R)‐Δ1(6)‐tetrahydrocannabinol‐5″‐oic acid (23) were synthesized by acid‐catalyzed condensation of (+)‐trans‐p‐mentha‐2, 8‐dien‐l‐ol (1) with the substituted resorcinols 18 and 19 obtained by a Wittig reaction between 3, 5‐bis(benzyloxy)benzaldehyde (7) and methyl 4‐bromobutanoate (10) or methyl 4‐bromo‐2(R, S)‐methylbutanoate (11) resp. with subsequent hydrogenation. The resulting methyl esters 20 and 21 were hydrolyzed to give acids 22 and 23.
Studies Related to Biological Detoxification of Kraft Pulp Mill Effluent. IV.The Biodegradation of 14‐Chlorodehydroabietic Acid with Mortierella isabellina
Authors: Kutney James P. , Dimitriadis Eugene , Hewitt Gary M. , Salisbury Philip J. , Singh Mahatam , Servizi James A. , Martens Dennis W. , Gordon Robert W.
Published: December 2004

One of the fish‐toxic chlorinated resin acids, 14‐chlorodehydroabietic acid (5), found in kraft mill effluent is examined. When exposed to the fungus Mortierella isabellina, 5 is converted into a number of hydroxylated derivatives which show low levels of toxicity to fish. These biotransformation products were isolated and characterized.
Studies related to biological detoxification of kraft pulp mill effluent. V. The synthesis of 12‐ and 14‐chlorodehydroabietic acids and 12,14‐dichlorodehydroabietic acid, fish‐toxic diterpenes from kraft pulp mill effluent
Authors: Kutney James P. , Dimitriadis Eugene
Published: December 2004

An improved synthesis of the isomeric 12‐ and 14‐chlorodehydroabietic acids (3 and 2, respectively) and 12,14‐dichlorodehydroabietic acid (4) is described. The monochioro isomers were conveniently separated as the imidazole derivatives, and conversion of the latter to the free acids or their corresponding methyl esters could be achieved in high yield. Studies involving microbial degradation of 2–4 are underway.
The Radical Cations of 4,5,7,13,15,16‐Hexamethyl‐ and 4,5,7,8,12,13,15,16‐Octamethyl [2.2]paracyclophane
Authors: Gerson Fabian , Lopez Javier , Hopf Henning
Published: December 2004

4,5,7,13,15,16‐Hexamethyl‐ (3) and 4,5,7,8,12,13,15,16‐octamethyl[2.2]paracyclophane (4) have been oxidized to their radical cations in solution under relatively mild conditions. Substantial hyperfine splittings in the ESR. spectra of 3⊕. and 4⊕. arise from the methyl protons, whereas those from methylene protons are very small. This result indicates that the ethano bridges, unlike the methyl substituents, are rather ineffective in delocalizing the positive charge in 3⊕. and 4⊕. It is in line with the interpretation proposed previously to rationalize the gas‐phase ionization potentials of multiply bridged [2N]cyclophanes and methyl derivatives of [2.2]paracyclophane. The π‐spin distributions in 3⊕. and 4⊕. are discussed in terms of a simple model in which the singly occupied orbitals are represented as the antibonding combinations of two benzene HOMO's.