bluuebunny/crossref_metadata_2025_split huggingface dataset:
Photochemical α‐Cleavage of β, γ‐Unsaturated Aryl Ketones: Competition between recombination/disproportionation and dissociation in geminate singlet and triplet radical pairs
Authors: Gonzenbach Hans‐Ulrich , Schaffner Kurt , Blank Bernd , Fischer Hanns 
Published: December 2004

AbstractThe photolysis of (R)‐(+)‐phenyl and (R)‐(+)‐p‐anisyl 1, 2, 3‐trimethylcyclopent‐2‐enyl ketone (1, 2) and the corresponding rac‐1‐ and 3‐desmethyl analogs (3, 4) led to isomerization due to formal 1, 3 aroyl migration and to formation of aryl aldehydes (7, 8), dienes (9, 10) and dimers (5, 6) of the cyclopentenyl radical. Evidence obtained from a chiroptical and mass spectrometric analysis of a crossing experiment and from photolytic CIDNP measurements including the use of CCl4 as a free radical scavenger, supports the conclusion (1): that the ketones undergo photochemical α‐cleavage predominantly in the triplet state; (2): that recombination and disproportionation reactions within the geminate singlet and triplet aroyl/allyl radical pairs (11) compete with the dissociation into free radicals (12): (3): that ketone isomerization by paths not involving polarizable radical intermediates is unimportant; (4): that no triplet oxa‐di‐π‐methane type rearrangement products are formed.
Darstellung von neutralen, lipophilen Liganden für Membranelektroden mit Selektivität für Erdalkali‐Ionen
Authors: Ammann Daniel , Pretsch Ernö , Simon Wilhelm 
Published: December 2004

AbstractThe preparation of a series of non‐cyclic, electrically neutral ligands, able to selectively complex alkaline earth metal cations, is described. Some of the compounds show high Ca2+ selectivity in membrane electrodes.
Über das 2‐Nitrothiophen
Authors: Maag Hubert , Manukian Badrig K. 
Published: December 2004

AbstractIsomerenreines 2‐Nitro‐thiophen (I) schmilzt bei ca. 41°. Im IR.‐Spektrum lässt sich die Gegenwart von 3‐Nitrothiophen (II) durch die für diese Verbindung charakteristische Absorption bei 834 cm−1nachweisen. Im UV. weist I ein einziges Maximum bei 298 nm auf.
A New Stereoselective Approach to Substituted Pyrrolidines by Intramolecular Ene‐Reactions. Preliminary communication
Authors: Oppolzer Wolfgang , Pfenninger Emil , Keller Kathrin 
Published: December 2004

AbstractIn der vorliegenden Mitteilung wird erstmals die Stereochemie intramolekularer En‐Reaktionen in Beziehung zur Geometrie der En‐Komponente systematisch beschrieben sowie ein neuer, präparativ ergiebiger Weg zu substituierten Pyrrolidinen aufgezeigt. Die N‐(cis‐Crotyl)‐N‐allylamide 1 werden beim Erhitzen ausschliesslich zu den Pyrrolidinen 2 isomerisiert. Unter identischen Bedingungen entstehen aus den N‐(trans‐Crotyl)‐N‐allylamiden 3 die gleichen Stereoisomeren 2 neben geringeren Mengen der epimeren Nebenprodukte 4. Durch die Umsetzungen 5 → 6, 7 8 + 9, 10 → 11 und 12 → 13 wird die thermische Überführung cyclischer Olefine in polycyclische Pyrrolidine unter sterischer Kontrolle mehrerer Chiralitätszentren illustriert. Während die Reaktion 14 → 15 schärfere Bedingungen erfordert, zeigen die Isomerisierungen 16 → 17 und 18 → 19 die glatte Beteiligung von C, C‐Dreifachbindungen an intramolekularen En‐Reaktionen bei weniger hohen Temperaturen.
Photosynthese von Dihydroazepinonen aus 2‐Alkyl‐indazolen
Authors: Heinzelmann W. , Märky M. 
Published: December 2004

AbstractN(2)‐alkylated indazoles are known to undergo two different photoreactions, namely (i) rearrangement into benzimidazoles in organic solvents and neutral aqueous solution, and (ii) solvolysis yielding o‐amino‐benzaldehydes or acetophenones, in strongly acidic solution.In diluted acidic solution (pH 3–4) both of these reactions are suppressed and a new photoreaction takes place, leading to two isomeric dihydroazepinones.Irradiation of 2,3‐dimethyl‐indazole in diluted sulfuric acid (pH = 3.8) yields 7‐acetyl‐1,3 dihydro‐2 H‐azepin‐2‐one and 3‐acetyl‐1,3‐dihydro‐2H‐azepin‐2‐one.
Ein einfacher Zugang zu 4‐hydroxy‐2,5‐dimethyl‐3(2H)‐furanon (furaneol), einem Aromabestandteil von Ananas und Erdbeere
Authors: Re Luciano , Maurer Bruno , Ohloff Günther 
Published: December 2004

AbstractFuraneol®Registered trade mark of Firmenich SA.
[4‐hydroxy‐2,5‐dimethyl‐3(2H)‐furanone (1)], a flavour component of pineapple and strawberry, has been prepared by a two‐step synthesis starting with readily available 3‐hexyne‐2,5‐diol.By the same method 4‐hydroxy‐5‐methyl‐3(2H)‐furanone (2) and 2‐ethyl‐4‐hydroxy‐5‐methyl‐3(2H)‐furanone (3a) have been prepared from 2‐pentyne‐1,4‐diol and 3‐heptyne‐2,5‐diol, respectively.
Photochemische Reaktionen. 73. Mitteilung. Neuartige Photoreaktionen des (±)‐trans‐β‐Jonon‐epoxids
Authors: von Wartburg Beat R. , Wolf Hans R. , Jeger Oskar 
Published: December 2004

AbstractThe racemic trans‐β‐ionone‐epoxide (7) upon irradiation with light of wavelength 254 nm (in pentane solution) gives rise to novel photochemical processes and formation of compounds 12, 13, 14, and 15.
Säurekatalysierte Umlagerung von trans‐5,6‐Dihydroxy‐5,6‐dihydro‐β‐jonon
Authors: Skorianetz Werner , Ohloff Günther 
Published: December 2004

AbstractOn treatment with acid, trans‐5,6‐dihydroxy‐5,6‐dihydro‐β‐ionone 2 undergoes a clean rearrangement to give a mixture of the furylketone 5 and the aliphatic triketone 6 in good yield.
Mechanistische Untersuchung zur Acyl‐Übertragung von Thioestern auf Amino‐ und Imidazolgruppen
Authors: Wenck Helmut , Polster Jürgen 
Published: December 2004

AbstractDie Reaktion von 4′‐Mercapto‐acetanilid‐acetat mit n‐Butylamin sowie mit Imidazol wurde bei pH 7,5 und 25,0° mit Hilfe von Reaktionsspektren, Extinktionsdifferenzen‐Diagrammen und Extinktionsdifferenzen‐Quotienten‐Diagrammen untersucht. Die Aminolyse des Thioesters ist «spektroskopisch einheitlich», die Imidazolyse verläuft in zwei linear unabhängigen Reaktionen: Bildung und Hydrolyse von N‐Acetyl‐imidazol.Durch formale Integration wurden die Geschwindigkeitskonstanten pseudo‐erster Ordnung ermittelt. Unter physiologischen Bedingungen verläuft die Imidazolyse schneller, bei Berücksichtigung der pK‐Werte muss jedoch das Amin als reaktiver betrachtet werden.
Fragmentierung von α,β‐Epoxyketoximen zu Alkinonen. Über Steroide, 228. Mitteilung
Authors: Wieland Peter , Kaufmann Heinz 
Published: December 2004

AbstractThe experimental details of the oxidoketone‐alkynone fragmentation brought about by the treatment of steroidal α,β‐oxido‐oximes with hydroxylamine‐O‐sulfonic acid in alcaline solution at room temperature are presented together with a discussion of the mechanism of this reaction. Studies of a ring closure reaction transforming the fragmentation products back into the starting α,β‐unsaturated ketones are discussed.
Über die Wanderung der Carboxylatgruppe bei der Benzilsäureumlagerung. 26. Mitteilung über Reduktone und Tricarbonylverbindungen
Authors: Rodé‐Gowal Heike , Dahn Hans 
Published: December 2004

AbstractThe benzilic acid rearrangement of ethyl α,β‐dioxo‐butyrate was studied by NMR.‐and UV.‐techniques. In weak alkaline media (pH < 10) the ester group is hydrolyzed first, then the carboxylate group migrates to form methyltartronate. The migration of the carboxylate group was proved by radioactive labeling. At higher pH‐values (pH > 11,5) the intakt ester group migrates, with ester hydrolysis occuring as a second step.
4‐Desoxy‐1‐thio‐β‐D‐glucose und deren Auro‐(1:1)‐Komplex
Authors: Vegh L. , Hardegger E. 
Published: December 2004

AbstractDie aus dem Formelschema ersichtlichen Umsetzungen führten von der 1,6;3,4‐Dianhydro‐D‐galaktose (Ia) über die 1,6‐Anhydro‐4‐desoxy‐D‐glucose (II) zur 1,2,3,6‐Tetra‐O‐acetyl‐4‐desoxy‐β‐D‐glucopyranose (III). Aus III wurden die instabile Acetohalogenose Vb und daraus das krist. Acetylderivat IIIa des (4‐Desoxy‐β‐D‐glucosyl)‐äthylxanthogenats hergestellt. Alkalische Umesterung mit Methanol führte von IIIa zum Natriummercaptid IIIb, aus dem die krist. 4‐Desoxy‐1‐thio‐β‐D‐glucopyranose (IIIc) gewonnen wurde. Der daraus hergestellte Auro‐(1:1)‐Komplex IIIe war instabil.
Zur Struktur der Scilliglaucosids. 56. Mitt. über Herzglykosided
Authors: Lichti Heinz , Niklaus Peter , von Wartburg Albert 
Published: December 2004

AbstractThe structure of scilliglaucoside, a cardiac active squill glycoside, is revised. The assignment of the new structural formula 1 is made on the basis of NMR. spectral data.
Etude des composés d'addition du monochlorure d'iode avec divers hydrocarbures aromatiques par les méthodes réfractométrique, diélectrique et calorimétrique
Authors: Schaer Jean‐Jaques , Torre Bona , Janjic Désimir 
Published: December 2004

AbstractThe composition of complexes resulting from the interaction of ICl with some aromatic hydrocarbons has been investigated by the method of continous variations applied to measurements of the refractive index, of the dielectric constant, and of the heat of reaction.Further, the equilibrium constant and the enthalpy of reaction for the formation of ICl. mesitylene complex were determined by dielectric and calorimetric methods. The latter yielded satisfactory results consistent with those obtained by UV. spectroscopy.
Nucleophilic Reactions at Tertiary Carbon. Part 3. σ‐ and π‐routes to the 9‐decalyl cation
Authors: Becker Konrad B. , Boschung André F. , Geisel Manfred , Grob Cyril A. 
Published: December 2004

AbstractThe generation of the 9‐decalyl cation by solvolysis of cis‐ and trans‐9‐decalyl chloride (1) has been reinvestigated. The results of product, rate and isomerization studies implicate stereoisomeric ion pairs as intermediates, as in the case of the solvolysis of other stereoisomeric tertiary chlorides (Parts 1 and 2).On the other hand, both symmetrically and unsymmetrically solvated 9‐decalyl cations are indicated in the cyclization of 4‐(cyclohexen‐1‐yl)butyl tosylate. No evidence was obtained that conformational isomers of the 9‐decalyl cation play a role as product determining intermediates.
Chemistry of Succinylsuccinic Acid Derivatives. Part I. On the photodimerization of diethyl succinylsuccinate
Authors: Sinnreich Joel , Batzer Hans 
Published: December 2004

AbstractTopochemically controlled photochemical dimerization of diethyl succinylsuccinate in the solid is reported. The structure evaluation by elemental and spectroscopic analysis of the product is given. The participation of chelated enols in photochemical cycloadditions in the crystalline solid state is here demonstrated for the first time.
Umwandlung von 6‐Methylen‐tricyclo[3.2.1.02,7]oct‐3‐en‐8‐onen in Polymethyltropyliumsalze
Authors: Peter‐Katalinić Jasna , Zsindely Janos , Schmid Hans 
Published: December 2004

AbstractWhen dissolved in trifluoroacetic or fluorosulfonic acid, 6‐methylene‐tricyclo[3.2.1.02,7]oct‐3‐ene‐8‐one derivatives of type 2 (;scheme 1); give polymethyltropylium salts in moderate to good yields by CO‐extrusion. These tropylium salts can be isolated pure as hexachloroplatinates. Thus the tricyclic compound 6 gives 1,2,4‐trimethyltropylium trifluoroacetate 19 in trifluoroacetic acid (;scheme 3);. This salt in CDCl3 is in equilibrium with its covalent cycloheptatriene (;tropilidene); form 20, the ratio of the two forms being 1.5–2.1/1. The tropylium salt 19 is reduced by lithium aluminium hydride to a mixture of 1,2,4‐trimethylcycloheptatrienes, isomeric with respect to the double bonds, which on hydride abstraction with trityl‐tetrafluoroborate gives again the 1,2,4‐trimethyltropylium salt 19 (;scheme 3);. From the trimethyl‐substituted tricyclic compounds 7 and 8, in trifluoroacetic acid, are obtained respectively the 1,2,4,6‐ and 1,2,3,4‐tetramethyltropylium ions (;22 and 24); (;schemes 4 and 5);. In this way the 1,2,3,5,6‐pentamethyl‐tropylium ion (;26); was obtained from 9 (;scheme 6);. With the higher substituted tropylium trifluoroacetates in CDCl3 the equilibrium tropylium trifluoroacetate ⇄ trifluoroacetoxycycloheptatrienes lies well to the left. The hexamethylated tricyclic compound 10 gives a small quantity of heptamethyltropylium trifluoroacetate (;27); and as the main product the C(;3);‐protonated species 28 (;scheme 7);, which when treated with aqueous sodium hydrogencarbonate yielded unchanged educt 10. ‐ The heptamethyltropylium ion (;27); was, apart from polymeric species, the only product from the treatment of starting material 10 with fluorosulfonic acid (;50%);; its salts have as yet not been isolated in their pure form, however.The mechanism for the rearrangement of the tricyclic compounds of type 2 into tropylium salts is presented for compound 6 in scheme 8: The first step is the protonation at C(;9);. Ring opening of the cyclopropane of the tertiary carbenium ion 29 gives the allylic ion 30, which then yields the aromatic tropylium salt 19 by carbon monoxide extrusion in a linear cheletropic reaction.The smooth conversion with strong acids of the easily accessible tricyclic compounds of type 2 to the corresponding polymethylated tropylium salts, presents a new and useful method for the synthesis of the latter compounds.
Über die Hydrolyse von Eisen(III)Salzlösungen. I. Die Hydrolyse der Lösungen von Eisen(III)chlorid
Authors: Feitknecht Walter , Giovanoli Rudolf , Michaelis Werner , Müller Max 
Published: December 2004

AbstractWhen a very diluted iron(III)chloride solution is slowly alkalified by a weak base, the deprotonation of [Fe(H2O)6]3+ proceeds in a first stage to form mono‐ and dinuclear hydroxoaquo‐complexes. In a second stage 4 dimers condense around a chloride ion to form an eight membered ring, an embryon, which grows fast to very small crystals of the composition Fe4O3(OH)5Cl and the structure of the β‐FeOOH. These crystalline micells remain colloidally dissolved. If the pH is raised above approximately 3.4 the Cl−‐ are exchanged against OH−‐ions and flocculation occurs. This shows that Pauli, assuming the micells of such sols to be polynuclear complex ions, is basically correct, and it follows that micells can also be micro‐crystals.When an iron(III)chloride solution is neutralized fast with a strong base, an ‘amorphous’ precipitation is obtained which gives with MoKα‐X‐rays only two broad reflections, showing that the iron oxide hydroxide octahedra are condensed in a highly disordered way. The coherently scattering areas of this precipitate are probably tetramers. Small amounts of primarily formed amorphous iron(III)hydroxide are transformed into β‐FeOOH.
Synthèse de sucres ramifiés et de sucres aminés ramifiés. Communication préliminaire
Authors: Bourgeois Jean‐Marc 
Published: December 2004

AbstractWhen treated with cyanide ion, 1,2:5,6‐di‐O‐isopropylidene‐α‐D‐ribo‐hexofuranos‐3‐ulose yields one or the other of the two corresponding epimeric cyanhydrines, depending on the experimental conditions. One of these epimers, reacted with ammonium cyanide, yields the corresponding amino‐nitrile, the other being unreactive. Several derivatives of these compounds are briefly described.
Über Pterinchemie. 45. Mitteilung. Eine neue und eindeutige Synthese isomerenfreier Pteroyl‐λ‐L‐glutamyl‐L‐glutaminsäure
Authors: Khalifa Esam , Bieri Jost H. , Viscontini Max 
Published: December 2004

AbstractA new and unequivocal synthesis of pteroyl‐λ‐L‐glutamyl‐L‐glutamic acid free of isomers is described. A melt of N(2′)‐acetyl‐6‐formylpterine and trimethyl‐N‐(p‐amino‐benzoyl)‐λ‐L‐glutamyl‐L‐glutamate was quantitatively converted to 6‐azomethin‐pterine‐trimethylester XI. NaBH4‐reduction followed by basic hydrolysis of acetyl and methyl ester groups gives pure pteroyl‐λ‐glutamyl‐glutamic acid in good yield.
α‐Chlor‐nitrone V: Substitutionsreaktionen an Olefin‐ und Benzolderivaten. Eine Methode zur Darstellung von β,γ‐un‐gesättigten und β‐ arylsubstituierten Aldehyden. Stereospezifische Bildung von tetra‐alkylsubstituierten Olefindoppelbindungen. Über synthetische Methoden, 9. (vorläufige) Mitteilung
Authors: Shatzmiller Shimon , Gygax Peter , Hall David , Eschenmoser Albert 
Published: December 2004

AbstractThe Ag+‐induced α‐chloro‐aldonitrone/olefin reaction in polar solvents can proceed by substitution, thereby providing a method for the preparation of β, γ‐unsaturated aldehydes. Positional as well as configurational retention of the olefinic double bond are mechanistically significant and preparatively useful characteristics of this process. Substitution also occurs with great ease at nucleophilic aromatic nuclei; this offers a simple preparative route to certain β‐aryl‐aldehydes.The results illustrate a general aspect of the chemistry of α‐chloro‐aldonitrones: the N‐alkenyl‐N‐alkyl‐nitrosonium‐ions derived from them can serve as preparative equivalents of the elusive corresponding α‐acyl‐carbonium‐ions.
Contribution à la phytochimie du genre Gentiana III. Etude des composés flavoniques et xanthoniques dans les feuilles de Gentiana lutea L. (2me communication)
Authors: Hostettmann Kurt , Bellmann Günter , Tabacchi Raphaël , Jacot‐Guillarmod André 
Published: December 2004

AbstractThe xanthone isogentisin and two flavonic heterosides (isocrientin‐4′‐O‐glucoside and isovitexin‐4′‐O‐glucoside) have been isolated from leaves of Gentiana lutea L. by means of column chromatography on polyamide. The determination of the structures and the NMR. spectra of the acetylated derivatives are reported.
Heterotricyclodecanes XVII. 2,7‐Dioxa‐twist‐4‐ene and 2,7‐dioxa‐twista‐4,9‐diene
Authors: Ackermann Peter , Ganter Camille 
Published: December 2004

Abstract2,7‐Dioxa‐twist‐4‐ene (3) and 2,7‐dioxa‐twista‐4,9‐diene (6) were prepared.
Hyperfine Shifts of the 13C‐NMR. in Protoporphyrin IX Iron (III) Dicyanide and Deuteroporphyrin IX Iron (III) Dicyanide
Authors: Wüthrich Kurt , Baumann Rudolf 
Published: December 2004

AbstractThe 13C‐NMR. in Zn(II) (Protoporphyrin IX), Fe(III) (Protoporphrin IX) (CN)2, Zn(II) (Deuteroporphyrin IX dimethylester), and Fe(III) (Deuteroporphyrin IX) (CN)2 have been identified, and the 13C hyperfine shifts in the iron complexes evaluated. In a partial analysis of these data the parameters QH, QCCHH, and QC′CHC, which characterize the isotropic coupling through hyperconjugation between the 1H and 13C nuclei of the porphyrin side chains and the unpaired electron spin density on the aromatic ring carbon atoms, have been re‐examined. This paper is part of an investigation of the electronic states in low spin ferric hemes and hemoproteins, and the relations between the electronic structures and the biological roles of these molecules.
Synthesis of [2‐p‐Fluorophenylalanine]oxytocin and its Desamino Analogue Using the S‐Acetamidomethyl Protecting Group
Authors: Marbach Peter , Rudinger Josef 
Published: December 2004

Abstract[2‐p‐Fluorophenylalanine]oxytocin (1a), desamino‐[2‐p‐fluorophenylalanine]oxytocin (1b), and desamino‐oxytocin (2) have been synthesised via intermediates containing S‐acetamidomethyl‐cysteine. The protected linear peptides were built up using both stepwise and fragment‐condensation procedures, and the S‐protecting groups were removed by iodine with simultaneous formation of the disulfide bridge. The uterotonic activities in vitro of the analogues have been determined. The close similarity of the 19F‐NMR. spectra indicates that the p‐fluorbenzyl side chain is freely exposed to the solvent in the disulfide‐bridged hormone analogues as well as in their S‐protected, acyclic precursors.
Quadricyclanes. Part I: Photoelectron spectra and electronic structure
Authors: Martin Hans‐Dieter , Heller Constanze , Haselbach Edwin , Lanyjova Zuzana 
Published: December 2004

AbstractThe photoelectron spectra of quadricyclane (3) and 3‐methylidene quadricyclane (4) have been measured. The results served as a basis for the elucidation of the electronic structure of these compounds, which agreed with theoretical calculations. It is found that the symmetry of the HOMO of 3 is different when compared to that of its valence isomer norbornadiene (1). The results also indicate that the structure of the highest occupied orbitals cannot be derived by only considering the Walsh‐orbitals of the two three‐membered rings. In addition one of the Walsh‐components of the four‐memebered ring has to be taken into account.
Preparation of Diazo Phenyl Sulfides. Kinetics and Mechanism of the Diazo Coupling Reaction of p‐Nitrobenzenediazo Phenyl Sulfide with β‐Naphthol under Various Conditions
Authors: Sakla Alfy Badie , Masoud Nabil Khalil , Sawiris Zaki , Ebaid Wagih Sadik 
Published: December 2004

AbstractAryldiazophenyl sulfides prepared from diazotised arylamines and thiophenol at controlled pH, are coupled with β‐naphthol yielding the corresponding azo dye.A kinetic study of the diazo coupling reaction of p‐nitrobenzenediazo phenyl sulfide with β‐naphthol under various conditions revealed that the reaction is of first order kinetics with respect to the diazo phenyl sulfide, and that the rate of coupling measured colorimetrically is influenced by the hydrogen ion concentration and by the ionising power of the medium.
Stereochemistry of Polynuclear Cadmium(II) Thioglycolates: Crystal structure of cadmium(II) bisthioglycolate
Authors: Bürgi Hans‐Beat 
Published: December 2004

AbstractCrystals of cadmiumbisthioglycolate are monoclinic, a = 10.06, b = 19.81, c = 8.74 Å, β=107.36°, space group P 21/c, Z = 4. A detailed three‐dimensional analysis shows that cadmium ions and mercaptide sulfur atoms form a two dimensional array of six‐membered and four‐membered rings (Fig. 1). All sulfur atoms bridge two cadmium ions. Of the two kinds of cadmium ions, one shows distorted tetrahedral coordination to four sulfurs, the other one distorted trigonal bipyramidal coordination (Fig. 4) to four sulfurs and to an axial alcohol oxygen atom.
The Mass Spectrometric Fragmentation of 1‐Heptyl Ions Derived from the Corresponding Halides
Authors: Fiaux André , Wirz Bernhard , Gäumann Tino 
Published: December 2004

AbstractWe have studied the fragmentation of 1‐heptyl ions resulting from the loss of halogen from the corresponding halide ions. All positions had been labelled with D and 13C, some positions even doubly labelled. The main processes are the loss of propene and, to a lesser extent, ethylene as neutral fragments. All carbon atoms have a definite probability of being lost with the olefin, those which are terminal having the smallest chance; this precludes an important contribution by direct scission. The source‐and the metastable‐decomposition produced much the same isotopic distribution in the fragments. The terminal hydrogen atoms also have a small chance of being rearranged, whereas those at non‐terminal positions show extensive scrambling. It seems that the fragmentation proceeds via cyclic structures which are rapidly attained and equilibrated amongst each other, but our results do not warrant suggestion of a detailed model.
Identification des composés phénoliques dans les feuilles de Homogyne alpina, Petasites albus, Petasites hybridus et Adenostyles alliariae
Authors: Schwendimann Jean‐Michel , Tabacchi Raffaele , Jacot‐Guillarmod André 
Published: December 2004

AbstractFour polyphenolheterosides have been isolated from the leaves of Homogyne alpina, Petasites albus, Petasites hybridus and Adenostyles alliariae by means of thin layer and column chromatography on polyamide. Isoquercitrine (II) has been isolated from Petasites albus, Petasites hybridus and Adenostyles alliariae; Astragaline (III) from Petasites albus and Petasites hybridus; Glucoluteoline (IV) from Adenostyles alliariae and Rutine (I) from Homogyne alpina. Piceine (V) has also been isolated from Homogyne alpina.
Über stereoselektive Synthesen und Reaktionen von 5,6‐Epoxy‐perhydroisoindolinen
Authors: Achini Roland , Loosli Hans‐Rudolf , Troxler Franz 
Published: December 2004

AbstractStereo‐selective syntheses of 2,5,6‐trisubstituted perhydroisoindolines are achieved by preparation of the three diastereoisomeric 5,6‐epoxy‐perhydroisoindolines and their reactions with nucleophiles, e.g. amines. The transformation of trans‐amino alcohols obtained in this way into cis‐amino alcohols is described.