bluuebunny/crossref_metadata_2025_split huggingface dataset:
Verdoppelungserscheinungen beim Ringschluss Von Peptiden. V. Relative Bedeutung der sterischen Hinderung und der Assoziation über Wasserstoff‐Brücken bei Tripeptiden. Spektroskopische Versuche zur Konformationsbestimmung. 12. Mitteilung über homodet cyclische Polypeptide
Authors: Schwyzer R. , Carrión J. P. , Gorup B. , Nolting H. , Tun‐Kyi Aung 
Published: December 2004

AbstractVarious factors inducing the doubling reaction during cyclization of small peptides are reviewed. To test their relative importance, derivatives of the tripeptide, Gly‐Pro‐Gly, and of the monodepsi‐dipeptide, glycyl‐glykolyl‐glycyl, have been subjected to cyclization : both undergo the doubling reaction to give cyclo‐glycyl‐L‐prolyl‐glycyl‐glycyl‐L‐prolyl‐glycyl and cyclo‐glycyl‐glykolyl‐glycyl‐glycyl‐glykolyl‐glycyl respectively. The «monomers» of this doubling reaction obviously cannot associate via H‐bridges according to Fig. 1 during the reaction, an association according to Fig. 12 could, however, be envisaged as working hypothesis. Steric hindrance seems to play an eminent rôle in the cyclization of tripeptides to cyclo‐hexapeptides.
Elektrometrische Endpunktsanzeige bei der Kupplungsreaktion
Authors: Büchler W. 
Published: December 2004

AbstractThe use of a polarised dropping mercury electrode as an electrometric indicator for coupling titrations is described. Ordinary diazo components can be employed even in admixture with organic solvents. The efficiency of this method is shown with some naphthols, naphthylamines, aminonaphthols, pyrazolones, and with acetoacet‐anilide. The standard deviation lies between 0.20 and 0.66%.
Reaktivität von Koordinationsverbindungen XI [1]. Mechanismus der Kupfer(II)‐katalysierten Autoxydation von o‐Phenylendiamin
Authors: Wüthrich K. , Fallab S. 
Published: December 2004

AbstractThe kinetics of the oxidation of o‐phenylenediamine (H2B) by molecular oxygen in the presence of cupric ion have been studied in the pH‐range 5.5 to 7.0. Complex formation between cupric ion and o‐phenylenediamine in aqueous solution is reversible when the solution is kept under nitrogen. On addition of 0, the ligand molecules are oxidised to 3,5‐dihydro‐2‐amino‐3‐imino‐phenazine.
Energie paramagnetische π‐Allyl‐carbonyl‐Komplexe des Eisens
Authors: Murdoch H. D. , Lucken E. A. C. 
Published: December 2004

AbstractThe reductive dehalogenation of halo‐π‐allyl‐tricarbonyliron complexes affords bis‐(π‐allyl‐tricarbonyliron) which coexists in solution with the paramagnetic π‐allyl‐tricarbonyliron. Similar paramagnetic complexes have also been obtained with substituted π‐ally1 ligands and also with both one or two of the carbonyl groups replaced by t‐phosphines. The elucidation of the structure of these products, based on analytical, electron spin resonance, and infrared data, is discussed.
Substitution électrophile aromatique. III. Étude cinétique de l'iodo‐déstannylation de dérivés benzéniques substitués et polycycliques aromatiques
Authors: Buchman O. , Grosjean M. , Nasielski J. , Martin R. H. 
Published: December 2004

AbstractThe rate of the reaction between iodine and a series of substituted phenyltri‐ methyltins in methanol has been determined and activation parameters estimated. The rates correlate well with the σ+ substituent constants, showing that the iodo‐ destannylation is an aromatic electrophilic substitution. The reaction shows interesting salt effects whose magnitude depends on the substituent, suggesting a rather polar transition state. The rates show no catalysis by iodide ions, implying that nucleophilic attack on tin is kinetically non‐significant.
Schwefel in aromatischen Verbindungen als Ligandatom in Chelatkomplexen
Authors: Kahmann K. , Sigel H. , Erlenmeyer H. 
Published: December 2004

AbstractThe hitherto unknown compounds 2‐(2′‐thieny1)‐pyridine and methyl α‐picolyl sulphide have been synthesized. The stability constants of Ni2+, Cu2+ and Zn2+ complexes with these two substances and with pyridine, α‐picoline, β‐picoline, γ‐picoline, and 2‐phenylpyridine have been measured and are discussed. Evidence for the coordination of the sulphur atom in methyl α‐picolyl sulphide as well as in the aromatic 2‐(2′‐thieny1)‐pyridine is given. It is also shown that thiophene is able to coordinate to Cu2+.
Welkstoffe und Antibiotika. 31. Mitteilung. Bicyclische Zwischenprodukte zur Synthese des Javanicins
Authors: Hardegger E. , Steiner K. , Widmer E. , Schmidt Th. 
Published: December 2004

AbstractNach Modellversuchen rnit 1‐Tetralon, 2‐Methyl‐ und 2‐Chlor‐1, 4‐naphtochinon konnten, ausgehend von 3‐Methyl‐5, 7, 8‐trimethoxy‐1‐tetralon(7), verschiedene Teil‐probleme der Synthese des Javanicins gelöst werden. U. a. gelang die Herstellung von Derivaten (12, 14, 15a, 15d, 17, 18) des Naphtopurpurins bzw. des Tetra‐ und Pentahydroxynaphtalins die, dem Javanicin‐A‐dimethyläther (12c) schon recht nahestehen. Der Synthese des Javanicins sollten, mit Ausnahme einer selektiven Äther‐spaltung, keine prinzipiellen Schwierigkeiten mehr entgegenstehen.
Über die Redox‐Eigenschaften von Hydroxyanthrachinonsulfonsäuren
Authors: Broadbent A. D. , Zollinger Hch. 
Published: December 2004

AbstractThe existence of monomolecular semiquinone free radicals as intermediate products of the alkaline reduction of 1,4‐ and 2,7‐hydroxyanthraquinone‐sulphonic acids could be proved by means of potentiometry, polarography, spectrophotometry and ESR.‐spectroscopy. The semiquinone formation constants have been determined.
Die Glykoside der Samen von Vallaris solanacea (ROTH) O. K. Strukturaufklärungen. Glykoside und Aglykone, 264. Mitteilung
Authors: Kaufmann Heinz 
Published: December 2004

AbstractThe seven new substances, isolated from the seeds of Vallaris solanacea (ROTH) O. K., have been shown to have the following structures:Vallaroside (substance D) = digitoxigenin‐α‐L‐vallaropyranoside, solanoside (substance F) = digitoxigenin‐α‐L‐acofriopyranoside, vallarosolanoside (substance E) = oleandrigenin‐α‐L‐vallaropyranoside, 16‐deacetyl‐16‐anhydro‐acoschimperoside P (substance H) = 16‐anhydro‐gitoxigenin‐α‐L‐acofriopyranoside.
Inosin‐N(1)‐oxid‐Nucleotide als Komplexbildner. I. Darstellung von Inosin‐N(1)‐oxid und dessen 5′‐Monophosphat aus Adenosin‐N(1)‐oxid und dessen 5'‐Monophosphat durch Desaminierung mit Nitrosylchlorid
Authors: Sigel H. , Brintzinger H. 
Published: December 2004

AbstractThe hitherto unknown compounds inosine N(1)‐oxide and inosine N(1)‐oxide 5′‐monophosphate have been synthesized by deamination of adenosine N(1)‐oxide and its monophosphate with nitrosyl chloride in dimethylformamide. This method is also useful for deamination of adenosine, adenosine 5′‐monophosphate and adenosine 5′‐triphosphate.
Über die Bindung der Wassermolekel in den Verbindungen MeIISO4, 1 H2O und MeIISeO4, 1 H2O: II. Infrarotspektrographische und kernmagnetische Resonanz‐Untersuchungen. (MeII = Mg, Ni, Cu, Co, Fe, Zn, Mn)
Authors: Oswald H. R. 
Published: December 2004

AbstractThe infrared spectra between 670 and 4000 cm−1 of MeIISO4·1H2O (MeII = Ni, Mg, Co, Zn, Fe, Mn and Cu), MeIISeO4·1H2O (MeII = Co and Zn) and a number of the corresponding D2O compounds are measured and discussed. The results are in good agreement with the crystal structure data and with measurements of the proton magnetic resonance. It must be concluded that the proposed formulations MeH2SO5 or Me(OH)SO4H are wrong. The compounds contain really a strongly bounded water molecule, and the present results give a sufficient explanation for the remarkable thermal stability of these hydrates.
Elektronenspinresonanz‐Untersuchungen von VO2+‐Komplexverbindungen in wässeriger Lösung
Authors: Wüthrich K. 
Published: December 2004

AbstractThe electron paramagnetic resonance and the optical absorption spectra of vanadyl(IV) complexes with a series of organic ligands have been investigated in aqueous solution. The g‐values as well as the nuclear hyperfine splitting constants are found to be sensitive to changes of the ligands. The g‐values indicate that the VO‐«double‐bonding» is maintained in all the compounds examined. The experimental results further suggest that the observed isotropic 51V‐hyperfine structure cannot be accounted for in terms of admixture of excited s‐electrons to be b2‐ground‐state, but rather in terms of «polarization» of filled inner s‐orbitals.
Die Niob(V)‐ und Tantal(V)‐Komplexe von Acetylaceton und Brenzcatechin, ausgehend von den Pentamethylaten
Authors: Gut R. , Buser Hansueli , Schmid Eduard 
Published: December 2004

AbstractpH‐titrations in methanolic solutions (μ = 1, N(CH3)4Cl, 20,0°) demonstrate that only 1:1 complexes are formed between NbV or TaV and acetylacetone (aa) The complexes Maa(OR)22+, Maa(OR)3+ and Maa(OR)4 (M = Nb, Ta; R = CH3) are shown to exist. Stepwise complex formation takes place with pyrocatechol (bz), and the existence of the complexes Mbz(OR)3, Mbz(OR)4−, M2bz2(OR)7−, Mbz2(OR)2− and Mbz3OR2− is established. The equilibrium constants of some of the complex forming reactions are evaluated. The new compounds Maa(OR)4, Maa(OR)3Cl, Tabz(OR)3, KTabz(OR)4, KTabz2(OR)2, K2Tabz3OR and M(OR)4Cl have been prepared.
Isolierung und Charakterisierung von Prämuscimol und Muscazon aus Amanita muscaria (L. ex FR.) HOOKER
Authors: Good R. , Müller G. F. R. , Eugster C. H. 
Published: December 2004

AbstractAus frischen Fruchtkörpern von Amanita muscaria (L. ex FR.) HOOKER, wurden Prämuscimol, C5H8O5N2, Smp. 145° (Zers.) und Muscazon, C5H6O4N2, isoliert. Beide Substanzen reagieren mit Ninhydrin gelb. Prämuscimol geht leicht unter Wasser‐ und CO2‐Abspaltung in Muscimol über. Prämuscimol wirkt wie Muscimol stark narkosepotenzierend.
Die Reaktion von Carbonsäuren mit Acetalen des N, N‐Dimethylformamids: eine Veresterungsmethode
Authors: Brechbühler H. , Büchi H. , Hatz E. , Schreiber J. , Eschenmoser A. 
Published: December 2004

AbstractThe reaction of carboxylic acids with acetals of N,N‐dimethylformamide represents a preparatively useful esterification method. Experiments bearing on the use, properties and scope of this reaction are described.
Über Pterinchemie. 14. Mitteilung. Neues Verfahren zur Darstellung und Stabilisierung von Tetrahydrofolsäure und Tetrahydropterinen
Authors: Bobst A. , Viscontini M. 
Published: December 2004

AbstractA new method for preparing hydrogenated pterines by catalytic hydrogenation in halogenated acids is described. The best results are obtained with platinum or rhodium in trifluoracetic acid. By this procedure the complete and selective hydrogenation of the pyrazine nucleus of pterine, its N‐methylated derivatives and of folic acid is effected in short time. For the first time the oxygen sensitive hydrogenation products have been isolated as hydrochlorides or sulphates. Some UV., NMR. and pKa data of 5,6, 7,8‐tetrahydrogenated pterines are given.
Selektive Spaltung substituierter Phenylsulfenyl‐Schutzgruppen bei Peptidsynthesen
Authors: Kessler W. , Iselin B. 
Published: December 2004

AbstractThe selective cleavage of the N‐sulphenyl protecting group from amino‐acids and peptides containing additional acid‐labile protecting residues has been investigated. Among various nucleophilic reagents tested for their ability to effect rapid and specific removal of the N‐sulphenyl groups, hydrogen cyanide, sulfurous acid and thioacetamide have been found to be particularly suitable. The application of this method to the solid phase synthesis of peptides is described and discussed.
Über die chemische Konstitution der mit Divinylsulfon vernetzten Cellulose. 12. Mitteilung über textilchemische Untersuchungen
Authors: Abend Th. , Stamm O. A. , Zollinger Hch. 
Published: December 2004

AbstractCotton and viscose fibres treated with divinyl sulphone under alkaline conditions were degraded in sulphuric acid. By column chromatography degradation products have been identified which contain two glucose units on mono‐ and dimeric sulphone derivatives, i.e. glucose ethers of 2,2′‐dihydroxyethylsulphone and of 2,2′‐bis‐(hydroxyethylsulphonyl)‐diethylether. This is the first direct chemical proof of the existence of cross‐linkages in cellulose treated with bifunctional reagents.
Beiträge zur Chemie der Si‐N‐Bindung, IX. Silane als Silylierungsmittel in der Silicium‐Stickstoff‐Chemie
Authors: Fink Walter 
Published: December 2004

AbstractDie Einführung von Silylgruppen in prim. und sec. Amine, in Silylamine, Aminosilane sowie Silazane, kann durch katalytische Silylierung der entsprechenden Verbindungen mit Silanen erfolgen. Als Katalysator dienen die Alkalimetalle oder deren Hydride.
Contribution à l'étude d'un produit de β‐hydroxyéthylation du rutoside. Partie 2. Indentification des constituants majeurs par spectrophotométrie ultraviolette
Authors: Courbat P. , Uhlmann G. , Guerne R. 
Published: December 2004

AbstractPar spectrophotométrie UV. on montre que les composants majeurs du mélange d'O‐hydroxyéthyl‐rutosides (appelé HER) sont le mono‐éther‐4′, le di‐éther‐7,4′, deux isomères tri‐éthérifiés l'un en 7, 3 et 4′, l'autre en 5, 7 et enfin le tétra‐éther‐5, 7, 3′, 4′.
Synthèse d'amino‐oxadiazoles ‐ 1, 2, 4
Authors: Eloy F. , Lenaers R. 
Published: December 2004

AbstractTwo new syntheses of 5‐amino‐1,2,4‐oxadiazoles are described. The first one is based on the reaction of guanidine on benzhydroxamyl chloride. The second is more general and consists in allowing primary or secondary amines, hydrazine or guanidine to react with 5‐trichloromethyloxadiazoles.
Notiz über das ESR.‐Spektrum des Phenalenyl‐Radikals
Authors: Gerson F. 
Published: December 2004

AbstractThe ESR. spectrum of the phenalenyl radical has been reexamined under increased resolution. The proton coupling constants (a1 = 6,29 and a2 = 1,805 gauss) are in agreement with the values reported by BENNETT [3]. Two 13C coupling constants have been determined (aC1 = 9,66 and aC2 ≈︁ aC10 = 7,84 gauss) and their assignment has been discussed.
Zur Kenntnis der Lipide aus dem Gehirn eines Buckelwals (Megaptera novae‐angliae BOROWSKY)
Authors: Lesch Peter , Benhard Karl 
Published: December 2004

AbstractThe lipid composition of a whale brain (Megaptera novae‐angliae BOROWSKY) previously fixed in formol for two years is reported. The Colamine‐Kephalines had been destroyed by the fixation procedure but all the other fractions could be isolated from the purified lipids, and we have analysed the fatty acid composition. Cortex and Cerebellum on the one hand and White Matter and Pons on the other hand showed a similar composition. In comparison with human brain striking parallelism was found in some instances, marked differences in others.
Umvinylierungen mit Vinyl‐phenyl‐äther als Vinylierungsmittel
Authors: Lüssi H. 
Published: December 2004

AbstractVinyl interchange of vinyl phenyl ether with phenols in the presence of mercuric acetate as a catalyst gives the corresponding vinyl aryl ethers in 40–75% yields. The reaction between vinyl phenyl ether and alcohols yields isolable quantities of vinyl alkyl ethers only when this product can be removed continuously during the reaction.
Photoinduzierte Isomerisation von 2‐(α‐Furyl)‐3‐acetyl‐1,4‐benzochinonen zu Isobenzofuran‐chinonen (= Benzo[c]furan‐chinonen)
Authors: Weisgerber G. , Eugster C. H. 
Published: December 2004

Abstract2‐(α‐Furyl)‐3‐acetyl‐1,4‐benzochinone und 2‐(α‐Furyl)‐3‐acetyl‐1,4‐naphtochinone lassen sich in aprotischen Lösungsmitteln durch Belichten mit langwellingem Licht in Isobenzofuran‐chinone (= Benzo[c]fruan‐chinone) der Struktur II umwandeln.
Recherches sur la formation et la transformation des esters LXVII. Note sur la scission des acides ω‐(N‐phénylthiocarbamylamino)‐alcoyl‐sulfuriques à divers pH
Authors: Cherbuliez Emile , Jindra H. , Rabinowitz J. 
Published: December 2004

AbstractIn aqueous solutions at 100°C varying from HCl 2N to NaOH 2N, N‐phenylthiocarbamoyl derivatives of aminoalkylsulfuric monoesters C6H5NHCSROSO3H are split in the following ways:

With R = CH2CH(CH3) or (CH2)3the scission of the monoester group is very rapid in the hole pH‐range studied, especially in alkaline medium; the resulting cyclic products, 5‐methyl‐2‐phenylamino‐thiazoline and 2‐phenylimino‐tetrahydrothiazine respectively, formed by nucleophilic attack of an unshared pair of the S atom on the C bearing the monoester group, have been isolated and identified.
With R = (CH2)4, the rate of the scission in alkaline or neutral medium is very much higher than that of an alkylsulfuric monoester; in these media a cyclic product is also formed (this time by nucleophilic attack of the unshared pair of the thiocarbamoylated N atom on the C bearing the monoester function) which has been isolated after alcaline scission, and identified as N‐phenylcarbomoyl‐pyrrolidine. In acid medium, no special influence of the phenylthiocarbamoyl group is observed.
With R = (CH2)5 or (CH2)6, the rate of the scission in alkaline medium is 30 to 1000 times lower than in the previous cases; no pure organic scission products have been isolated. In acid or neutral medium, these two esters behave like usual alkylsulfuric acids.
Über Pterinchemie 18. Mitteilung [1] Monohydro‐ und Trihydropterin‐Radikale
Authors: Ehrenberǵ A. , Hemmerich P. , Müller F. , Okada T. , Viscontini M. 
Published: December 2004

AbstractBy oxydation of N(5)‐methyl‐6,7‐diphenyl‐5,6‐dihydro‐ and N(5)‐methyl‐6,7‐diphenyl‐5,6,7,8‐tetrahydro‐pterine derivatives with perhydrol 8‐monohydro‐ and 6,7,8‐trihydro‐pteridine radical cations are produced which are sufficiently stable for detection and structural elucidation by ESR. hyperfine analysis. The biological implications of these radicals for pteridine dependent hydroxylation and methyl transfer from 5‐methylfolinic acid are discussed.
Die Enonamin‐Enolimin‐Tautomerie
Authors: Grob C. A. , Wilkens H. J. 
Published: December 2004

AbstractA study of the ultraviolet, infrared, and nuclear magnetic resonance spectra of Δ8,9‐octahydro‐7‐quinolone (7a) and of the corresponding N‐ and O‐ethyl derivatives 8 and 9, respectively, confirms that in cases of potential enonamine‐enolimine tautomerism the enonamine form predominates. This also applies to vinylogous amides capable of intramolecular hydrogen bonding, such as 2‐benzylaminomethylene‐ and 2‐phenylaminomethylene‐cyclohexanone, 10 and 11, respectively. Exeptions are only observed in cases where the enolimine form is stabilized by special factors, such as aromaticity.
Die Struktur des quartären Alkaloides Macrosalhin
Authors: Khan Zaheer M. , Hesse M. , Schmid H. 
Published: December 2004

AbstractFrom the stem bark of Alstonia macrophylla Wall. a new quaternary alkaloid macrosalhine, C21H27O2N, has been isolated in small amounts as chloride or thiocyanate. On the basis of its chemical transformations and particularly its spectral properties (NMR., mass) the structure 1 has been proposed for it. Macrosalhin therefore represents a new skeletal type in the alkaloid field.
Oxydative Umwandlung von 17‐Alkoxy‐aspidospermidin‐Derivaten in 17, 17‐Dialkoxy‐17, 18‐dihydro‐1, 18‐dehydro‐aspidospermidine
Authors: Bycroft B. W. , Goldman L. , Schmid H. 
Published: December 2004

AbstractTreatment of 17‐alkoxy‐aspidospermidine derivatives with iodine and sodium hydroxide in methanolic or ethanolic solution yields the corresponding 17, 17‐dialkoxy‐17, 18‐dihydro‐1, 18‐dehydro‐aspidospermidine. Hence compounds 1 and 2 in methanol give the oxidation products 8 and 3, respectively. In ethanol, 4 is converted to 5, 2 to a mixture of 6 and 7; 4 in methanol yields a mixture of 6 and 7 in a different ratio.
Komplexe von Nonactin und Monactin mit Natrium‐, Kalium‐und Ammonium‐Ionen
Authors: Pioda Lavinia A. R. , Wachter H. A. , Dohner R. E. , Simon W. 
Published: December 2004

Abstract1:1‐Complexes between nonactin and monactin, and sodium, potassium, and ammonium thiocyanate are described.
Recherches sur la formation et la transformation des esters LXXV[1]. Amines, amino‐alcools et aminoalcoyl‐monoesters des acides orthophosphorique et sulfurique: thiocarbamylation par l'isothiocyanate d'o‐méthoxycarbonylphényle sans ou avec cyclisation intramoléculaire
Authors: Cherbuliez Emile , Willhalm B. , Espejo O. , Jaccard S. , Rabinowitz J. 
Published: December 2004

Abstracto‐Methoxycarbonyl‐phenylisothiocyanate V and primary alkylamines (R″NH2) reacted in the appropriate medium yield the corresponding 2‐mercapto‐3‐alkyl‐3, 4‐dihydro‐quinazolinone‐4 derivatives VI (the NH2 group is thiocarbamoylated by the NCS group and then acylated in an intramolecular reaction by the COOCH3 group with elimination of CH3OH).
Welkstoffe und Antibiotika. 36. Mitteilung [1]. Synthese von Verbindungen der Lycomarasmin‐Reihe
Authors: Hardegger E. , Andreatta R. , Szabo F. , Zankowska‐Jasinska W. , Rostetter Ch. , Kindler H. 
Published: December 2004

AbstractAusgehend von L‐Asparaginsäure (I), bzw. L‐Asparagin (Ia) wurden über den L‐Asparaginsäure‐diäthylester (II) auf verschiedenen Wegen über die Zwischenprodukte III, VI, VIa, b, c, d, e, VII die racemischen Diastereomeren der Diamino‐tricarbonsäure IX erhalten. Versuche zur präparativen Herstellung der Äthoxycarbonyl‐ und Methoxycarbonyl‐anhydro‐lycomarasminsäureester X, Xa aus den Chloracetyl‐Derivaten VId, e, und der Anhydrolycomarasminsäure (XI) aus der Diamino‐tricarbonsäure IX waren ohne Erfolg.
Notiz über die Massenspektren von N‐Oxiden. 8. Mitteilung über das massenspektrometrische Verhalten quartärer Stickstoffverbindungen
Authors: Bild N. , Hesse M. 
Published: December 2004

AbstractBeim Vergleich der Massenspektren verschiedener N‐Oxide ergeben sich bezüglich der Pike M+‐16 und M+‐17 bei denjenigen aromatischer Amine allgemein gültige Verhaltensweisen. Die N‐Oxide aliphatischer Amine hingegen zeigen zusätzlich zu diesen beiden Zerfallsmöglichkeiten noch M+‐18‐Pike. Wenig intensive Molekular‐Ionenpike, thermische Abspaltung von O und H2O und das gänzliche Fehlen von M+‐16‐, M+‐17‐ und M+‐18‐Piken können neben den beiden Folgeprodukten der Cope‐Reaktion in hohem Masse den massenspektrometrischen Nachweis dieser Verbindungsklasse erschweren.
Über die Struktur des Callichilins. 125. Mitteilung über Alkaloide
Authors: Agwada V. , Gorman A. A. , Hesse M. , Schmid H. 
Published: December 2004

AbstractThe dimeric indole alkaloid callichiline (2), C42H48O5N4, has been isolated from Callichilia (Hedranthera) barteri (HOOK. f.) PICHON along with vobtusine (1) and beninine (3). Its chemical reactions and spectral properties have shown that callichiline is made up of the same two monomeric ‘halves’ as vobtusine, that is beninine (3) and the vincadifformine analogue of beninine.
Die Kristallstrukturen von Mn5O8 und Cd2Mn3O8
Authors: Oswald H. R. , Wampetich M. J. 
Published: December 2004

AbstractThe crystal structures of Mn5O8 and Cd2Mn3O8 are determined from single crystal and high resolution X‐ray powder data. Both structures have very similar monoclinic unit cells, space group C–C2/m, and are isotypic:

equation image

Hence, the true formula of Mn5O8 is MnMnO8. The crystal structure consists of pseudohexagonal MnIV sheets (bc) with similar oxygen sheets on either side, giving a distorted octahedral coordination to the MnIV. As every fourth MnIV is missing in these “main layers”, their composition becomes Mn3O8, and chains of coordination octahedra linked by common edges become distinct. Above and below the empty MnIV sites are either MnII or CdII completing the composition MnMnO8 or Cd2Mn3O8 respectively. Examples of similar “double layer” structures are given.
Über die Reaktion von tertiären Vinylcarbinolen mit Isopropenyläther Eine neue Methode zur Herstellung von γ, δ‐ungesättigten Ketonen
Authors: Saucy G. , Marbet R. 
Published: December 2004

AbstractA novel acid‐catalysed reaction of isopropenyl ether with tertiary vinyl carbinols giving γ, δ‐unsaturated ketones in high yields is described. Methylheptenone, geranylacetone, farnesylacetone and analogous ketones were prepared by this convenient and efficient new method, which involves a Claisen‐rearrangement step.