bluuebunny/crossref_metadata_2025_split huggingface dataset:
Die Stereochemie der Irone
Authors: Rautenstrauch V. , Ohloff G. 
Published: December 2004

AbstractThe 6 R configuration of (+)‐cis‐γ‐irone [(+)‐4] was established by chemical correlation with (—)‐camphor. (+)‐cis‐γ‐irone [(+)‐4] was converted into (+)‐cis‐α‐irone [(+)‐1], (−)‐trans‐α‐irone [(minus;;)‐2], and (+)‐β‐irone [(+)‐3], which therefore also have the 6 R configuration. The 2 S configurations of (+)‐cis‐α‐irone [(+)‐1] and (+)‐trans‐α‐irone [(+)‐2] were determined by comparison of their circular dichroism with that of R‐α‐ionone [(+)‐5]. The 2 S configuration of (+)‐cis‐γ‐irone [(+)‐4] was established by chemical correlation with (+)‐cis‐α‐irone [(+)‐1].
„Nichtcarbenoide”︁ Zwischenstufen bei der Fragmentierung von α‐Cyclopropyltosylhydrazonen
Authors: Ohloff G. , Pickenhagen W. 
Published: December 2004

AbstractThe sodium salts of the tricyclic tosylhydrazones 1, 4 and 5 yield by base‐catalyzed fragmentation between 130–160° the monocyclic ring expansion products 2, 3 and 6. IR.‐spectrometry suggests a diazoalkane A as the principal intermediate of the fragmentation. Besides the known carbene mechanism the reaction is considered to pass through a noncarbenoid intermediate.
Darstellung von (+)‐ und (−)‐7‐Hydroxy‐dihydrocitronellal aus (+)‐Pulegon. Ein Beitrag zur Kenntnis olfaktorischer Eigenschaften von Enantiomeren
Authors: Skorianetz W. , Giger H. , Ohloff G. 
Published: December 2004

AbstractThe enantiomers of 7‐hydroxy‐dihydrocitronellal have been prepared stereo‐specifically from (+)‐pulegone by a sequence of analogous reactions. The olfactory properties of the final products and of the intermediates have been investigated. In most cases they exhibit remarkable qualitative and quantitative differences in odour.
Applications synthétiques de la cyclisation d'alcools tertiaires γ‐éthyléniques en α‐bromotétrahydrofurannes sous l'action du N‐bromosuccinimide. II. Cyclisation du (±)‐nérolidol en diméthyl‐2,5‐(méthyl‐4‐pentène‐3‐yl)‐2‐cycloheptène‐4‐one, tétraméthyl‐3, 3, 7, 10‐oxa‐2‐tricyclo[5.5.0.01,4]‐dodécène‐9, β‐acoratriène, cédradiène‐2,8, épi‐2‐α‐cédrène et α‐cédrène
Authors: Demole E. , Enggist P. , Borer Mlle C. 
Published: December 2004

AbstractThe ionic reaction of (±)‐nerolidol (cis/trans mixture) with N‐bromosuccinimide in CCI4 at room temperature afforded 2‐methyl‐2‐vinyl‐5‐(2‐bromo‐6‐methyl‐hept‐5‐en‐2‐yl)‐tetrahydrofuran (4) in high yield. This compound was readily dehydrobrominated by refluxing collidine to the intermediate allyl vinyl ether 8, which immediately undergoes [3,3]‐sigmatropic rearrangement to 2, 5‐dimethyl‐2‐(4‐methylpent‐3‐enyl)‐cyclohept‐4‐enone (11). By treatment with SnCI4 in nitromethane at room temperature 11 was in turn cyclised to cis‐3, 3, 7, 10‐tetramethyl‐2‐oxa‐tricyclo[5.5.0.01,4]dodec‐9‐ene (12), an oxetane closely related to the sesquiterpene carotol. This oxetane (12) underwent a stereospecific ring contraction when treated by Lewis acids such as H2AICI or HAlCI2, to form the β‐acoratriene (13).Finally, the BF3‐catalysed cycli‐ sation of the latter afforded 2,8‐cedradiene (19) from which 2‐epi‐α‐cedrene (20) was easily obtained by partial, regio‐selective hydrogenation. α‐Cedrene (22) itself, together with its epimer 20, resulted from the Wolff‐Kishner reduction of the 2‐epi‐α‐cedren‐3‐one (21), prepared by selective hydroboration/oxidation of 19.A transformation of nerolidol to α‐cedrene was thus achieved by a unique stepwise cyclisation process.
Recherches sur les arǒmes. 17e communication. Sur l'arǒme de framboise, IV
Authors: Winter M. , Enggist P. 
Published: December 2004

AbstractThe neutral fraction of medium volatility from raspberry oil has been analysed by gas chromatography and mass spectrometry. From the large number of constituents thirtynine have been identified, 24 of them for the first time, including dihydro‐β‐ionone (I), epoxy‐β‐ionone (II), damascenone (III)1, theaspirane (IV) and 2‐hexen‐4‐olide (V). According to these results raspberry oil consists mainly of alcohols, ketones, aldehydes and lactones.
Eine neue Synthese von 3,6‐Dialkyl‐1,2,4,5‐tetrazinen
Authors: Skorianetz W. , Sz. Kováts E. 
Published: December 2004

AbstractA new synthesis of 3,6‐dialkyl‐1,2,4,5‐tetrazines (or ‐s‐tetrazines), 4, is described (see reaction scheme [1→2→3→4]). The 3,6‐dialkyl‐hexahydro‐s‐tetrazines, 2, R = n‐alkyl, are readily available by the reaction of fatty aldehydes and hydrazine. s‐Tetrazines with branched substituents and mixed alkyl‐s‐tetrazines can also be prepared by the same procedure, however, in lower yields.
Stereospecific Olefin Synthesis via Lithium Vinylcuprates
Authors: Näf F. , Degen P. 
Published: December 2004

AbstractThe conjugate addition of cis‐ or trans‐1‐alkenyl‐cuprolithium complexes (RCHCH)2CuLi · XnR  alkyl, X  ligands such as ether, tetrahydrofuran, (CH3O)3P and (n‐Bu)3P. Physical studies to determine the structure of these copper reagents are in progress, see footnote 20 of reference [1].
to α, β‐unsaturated carbonyl compounds was found to occur with high retention of double bond geometry, affording isomerically pure cis‐ or trans‐γ, δ‐ethylenic carbonyl compounds. The same 1‐alkenylcuprates also react stereospecifically with alkyl halides to give isomerically pure cis‐ or trans‐olefins.
Le mécanisme de l'hydrolyse acide des aryl‐diazométhanes
Authors: Dahn H. , Diderich G. 
Published: December 2004

AbstractIn the acid catalysed hydrolysis of three monoaryl‐diazomethanes (p)‐nitrophenyl‐diazométhane (I),p‐chlorophenyl‐diazomethane (II), phenyl‐diazomethane (III), absence of exchange H‐D, solvent isotope effects about 2,6, and general acid catalysis prove that proton transfer is rate determining (A‐SE2 mechanism). Like otherA‐SE2 reactions, the hydrolysis of I is shown to obey theBrønstedcatalysis law with a variety of carboxylic acids; for eight of these acids, αBwas found to be 0,69 ± 0,06.
Umsetzung von 3‐O‐Acetyl‐14‐anhydrodigitoxigenin und 3‐O‐Acetyldigitoxigenin mit Osmiumtetroxid
Authors: Schüpbach M. , Krasso A. F. , Binder M. , Tamm Ch. 
Published: December 2004

AbstractTreatment of 3‐O‐acetyl‐14‐anhydrodigitoxigenin (1) with 1.1 equivalents of OsO4 gave both the 14α, 15α‐diol 2 and the 14β, 15β‐diol 4. Degradation to the corresponding methyl etianates 7 and 10, respectively, established their stereochemistry. Treatment of both the 14‐hydroxy‐15‐acetoxy‐cardenolides 3 and 5 with OsO4 leads to the expected mixtures of 20, 22‐diols, a partial separation of which was achieved after acetylation. The butenolide ring of 3‐O‐acetyl‐digitoxigenin (25) also reacted with OsO4, yielding the two 20,22diols 26 and 27, the stereochemistry of which has tentatively been assigned on the basis of NMR. data.
Nitration of Durene and Pentamethylbenzene with Nitronium Salts in Nitromethane and Acetonitrile
Authors: Hunziker E. , Penton J. R. , Zollinger H. 
Published: December 2004

AbstractNature and proportions of the products formed in the nitrations mentioned in the title are affected by the process of mixing.Pentamethylnitrobenzene, formed initially in the nitration of pentamethylbenzene, is attacked by a nitronium ion at a position meta to the nitro‐group. In the σ‐complex formed, loss of a proton from a methyl group leads to production of by‐products and release of nitrite ions. The nitrous acid formed is protonated, and water is displaced from the nitrous acidium ion by the anion, PF6⊖, giving the nitrosonium ion which forms a 1:1 symmetric molecular complex with pentamethylbenzene. A similar complex is formed in the reaction between durene and nitronium salts.The results are consistent with the view that no σ‐bond is formed between the aromatic compound and the nitrosonium ion.
Synthese von 2‐Thia‐6‐aza‐adamantan und Derivaten
Authors: Ganter C. , Portmann R. E. 
Published: December 2004

AbstractThe synthesis of 2‐thia‐6‐aza‐adamantane (19) and several of its derivatives was achieved starting from 9‐azabicyclo[3.3.1]nona‐2,6‐diene (9) which was prepared from cis, cis‐cycloocta‐1, 5‐diene (1). Transannular addition of sulfur dichloride to its N‐benzenesulfonyl and N‐formyl derivatives 10 and 11 yielded the tricyclic dichlorides 12 and 13, respectively; the 2‐thia‐6‐aza‐adamantanes 14–19 were synthesized from 13.
2β, 13‐Oxido‐apotrichothecane: Synthese, chemische und physikalische Eigenschaften. Verrucarine und Roridine, 23. Mitteilung
Authors: Schumacher R. , Gutzwiller J. , Tamm Ch. 
Published: December 2004

AbstractStarting from the 12,13‐epoxy‐trichothecanes roridin C (trichodermol) (1), verrucarol (15) and trichothecolone (25), the isomeric 2β, 13‐epoxy‐apotrichothecanes 9, 20 and 33 have been synthesized. In these compounds the oxetane group proved to be unexpectedly stable to mineral acids and complex metal hydrides, probably due to its fusion to a cyclopentane ring. The IR. and NMR. spectra of the oxetanes are discussed.
Tetrajodterephtalsäure‐derivate als Röntgen‐Kontrastmittel
Authors: Suter H. , Zutter H. , Brunner J. 
Published: December 2004

AbstractNew monoamides and diamides of tetraiodoterephthalic acid have been synthesized for evaluation as X‐ray contrast agents. Solubility, toxicity, bilitropism, urotropism, and in some cases cholecystographic quality of these compounds are given.
Steroid Total Synthesis, Part II; (−)‐17β‐Hydroxy‐des‐A‐androst‐9‐en‐5‐one
Authors: Saucy G. , Borer R. 
Published: December 2004

AbstractBased on the results obtained in the racemic series (part I), (—)‐17β‐hydroxy‐des‐A‐androst‐9‐en‐5‐one has been synthesized, starting with (S)‐(—)‐5‐heptanolide. The key step, viz. the condensation of (S)‐(—)‐7‐hydroxy‐1‐nonen‐3‐one (or its amine adduct) with 2‐methyl‐cyclopentane‐1, 3‐dione involves an asymmetric induction. Model experiments with (R)‐(+)‐5‐decanolide leading to the enantiomeric homolog of the BCD‐tricyclic compound are also described.
Dérivés de nucléotides d'intérêt biologique VIII. Synthèse de quelques analogues de l'acide adénosine‐triphosphorique (ATP)
Authors: Gabbai A. , Marcus I. , Falbriard J. G. , Posternak Ht. 
Published: December 2004

AbstractAnalogues of ATP belonging to the following classes have been prepared: N6‐monoacyl derivatives, N6‐mono‐ and ‐di‐alkyl derivatives, 6‐deamino‐ATP, 8‐bromo‐ATP, 8‐amino‐ATP and ATP‐N(1)‐oxide. With the exception of the last compound, the corresponding AMP derivatives have been used as intermediates in these preparations.
Dérivés de nucléotides d'intérêt biologique, IX. Essais enzymatiques avec des analogues de l'acide adénosine‐triphosphorique (ATP). Communication préliminaire
Authors: Gabbai A. , Posternak Ht. 
Published: December 2004

AbstractThe reactivity, as substrates for hexokinase and glycerokinase, of some analogous of ATP has been compared with that of ATP.
Photochemische Reaktionen. 66. Mitteilung. UV.‐Bestrahlung von 11‐Oxo‐Steroiden IV Neuartige Photoisomerisierung von 3,20‐Di‐äthylendioxy‐11‐oxo‐δ14‐5α‐pregnen
Authors: Gull P. , Wehrli H. , Jeger O. 
Published: December 2004

AbstractUV. ‐irradiation of the 11‐oxo‐δ14‐5α‐pregnene derivate 16 gives rise to a novel photochemical reaction. The preferential attack of the photochemically excited carbonyl on CH‐8 furnishes the tertiary cyclopropanol compound 18 in high yield.
Die oxydative Anlagerung von Methyldichlorsilan an Tetrakis‐(triphenylphosphin)‐platin(0)
Authors: Fink Walter , Wenger Adrian 
Published: December 2004

AbstractBy oxydative addition of methyldichlorosilane to tetrakis‐(triphenylphosphine)‐platinum(0) three types of silicon‐platinum complexes are formed.
Etude par analyse thermique différentielle des transformations ordre‐désordre dans des alliages or‐cuivre riches en or
Authors: Lüthy H. , Isler C. , Tissot P. 
Published: December 2004

AbstractBy differential thermal analysis of some Au‐Cu alloys the order‐disorder transformation AuCu IAuCu II of the compound AuCu is shown to be a first order transformation accompanied by a variation of enthalpy. This method has also allowed to detect a certain order in alloys with more than 75 at‐% Au.
The Identity of the gamma Modification of Basic Lead Azide Type I
Authors: Todd G. , Tasker M. P. 
Published: December 2004

AbstractPublished information on the basic lead azide series is discussed with particular reference to the gamma modification of basic lead azide I. A sample of this product has been prepared and the absence of significant impurity confirmed by X‐ray diffraction analysis. Infrared absorption analysis has indicated the presence of PbO bonding and the absence of HO bonding. The product is therefore an oxyazide containing neither hydroxide nor water of crystallisation. Chemical analysis confirms that the Pb(N3)2:PbO ratio is less than one.
Synthese, Struktur und Reaktionen von Secosteroiden mit einem mittleren Ring V. Photochemische Cyclisation von cis‐ und trans‐3β‐Acetoxy‐5‐oxo‐Δ1(10)‐5, 10‐secocholesten
Authors: Mihailović M. Lj , Lorenc Lj. , Popov N. , Kalvoda J. 
Published: December 2004

AbstractIn continuation of our work on transannular cyclizations of trans‐3β‐sacetoxy‐5, 10‐seco‐cholest‐1 (10)‐en‐5‐one (1), the ringclosure of this compound and of its cis‐isomer (11) under UV.‐irradiation was examined: both yield the same mixture of oxetanes 2 and 3 exhibiting the natural steroid skeleton.
Photochemisches Verhalten von 1‐ und 2‐alkylierten 1,2‐Dihydronaphtalinen
Authors: Heimgartner H. , Ulrich L. , Hansen H. ‐J. , Schmid H. 
Published: December 2004

AbstractIrradiation of 1‐alkyl‐substituted 1,2‐dihydronaphthalenes (10, 11, 12) with a lowpressure mercury lamp yields by ring opening ω‐vinyl‐o‐quinodimethanes, which undergo [1, 7] H‐shifts to give 1,2‐divinyl‐benzenes (8, 18, 23; cf. schemes 2, 3 and 4). In a further photoreaction of the divinylbenzenes, benzobicyclo [3.1.0]hex‐2‐enes (17, 19, 22) are formed. 2‐Alkyl‐substituted 1,2‐dihydronaphthalenes (13, 14, 15, 16) are transformed by irradiation into ω‐vinyl‐o‐quinodimethanes, which show [1, 7] H‐shifts to yield in this case 2‐(buta‐1′, 3′‐dienyl)‐toluenes (9, 25, 26, 27; cf. schemes 6 and 7). The irradiation of 1‐methyl‐ (10) and 1‐ethyl‐1, 2‐dihydronaphthalene (11) with a high‐pressure mercury lamp produces, besides the products of irradiation using the lowpressure lamp, 2‐ethyl‐allenylbenzene (24), and (from 11) 4‐exo‐ethyl‐benzobicyclo[3.1.0]hex‐2‐ene (exo‐20) and 2‐propyl‐allenylbenzene (21), respectively (cf. scheme 5). Obviously, these products arise from a photreaction of the primarily formed ω‐vinyl‐o‐quinodimethanes a.
Über Pterinchemie. 39. Mitteilung. Zur Frage des “aktiven Formaldehyds”. Wird durch Formaldehyd‐Anlagerung an Tetrahydrofolsäureanaloge ein Imidazolidinring gebildet?
Authors: Viscontini M. , Bieri J. 
Published: December 2004

AbstractEs werden Versuche mit Tetrahydrofolsäure‐Modellsubstanzen unternommen, um die eigentliche Struktur des sogenannten «aktiven Formaldehyds» abzuklären. Alle Addukte der tetrahydrierten Substanzen mit Formaldehyd erweisen sich als Hydroxymethyl‐ und nicht als Imidazolidin‐Derivate. Ob das Additionsprodukt des Formaldehyds mit Tetrahydrofol‐säure ebenfalls ein Hydroxymethyl‐Derivat ist, bleibt noch abzuklären.
Composés d'addition des chlorures de terres rares avec le méthanol, l'éthanol et le propanol‐2. Préparations, solubilités et réactions de transsolvatation
Authors: Merbach A. , Pitteloud M.‐N. , Jaccard P. 
Published: December 2004

AbstractBy reaction of hydrated rare earths chlorides (M = La, Nd, Sm, Gd, Dy, Er, Yb, Y) with orthoformates, the following adducts have been prepared: MCl3· 4MeOH, MCl3 ·3EtOH (M = La, Nd, Sm, Gd, Yb), MCl4 · 4 EtOH (M = Dy, Er, Y); adducts MCl3 · 3iso‐PrOH have been prepared by successive action of methyl orthoformate and of 2‐propanol. The solubilities of these adducts in the corresponding alcohols at 25° (for the lanthanum adducts equally at 0 and 50°) are given. Two examples of the transsolvatation of these compounds, yielding adducts with weakligands, are described.
Metal Complexes of Free Radicals. Part II: Identification and structures of radical complexes of alkaline earth metals and zinc
Authors: Clopath P. , v. Zelewsky A. 
Published: December 2004

AbstractThe formation of chelate complexes between free radicals and closed‐shell metal ions is observed by ESR. spectroscopy. High resolution spectra of 1:1 complexes formed between the radical anion of glyoxal‐bis‐(N‐t‐butylimine) (GLIR) and Mg2+, Ca2+ and Zn2+ are completely analysed. The complexes formed in dimethoxyethane or tetrahydrofuran solutions are Ca(GLIR)+, Mg(GLIR)X, Zn (GLIR)X and Zn(GLIR)Y−2, where X = Cl−, Br−, I−, and Y = CN−, NCS−. The formation of the heterometallic, binuclear cyanide‐bridged complex Zn(GLIR)Fe(CN)63− is also described. Isotropic coupling constants are given for protons and 14N in GLIR as well as for the metal nuclei and magnetic nuclei in the groups X and Y. Stabilities, structures and ESR. parameters of these radical complexes are discussed.
The Stabilization of Bridged Structures of Ethanes
Authors: Hoffmann Roald , Williams J. E. 
Published: December 2004

AbstractThe source of the instability of D2h, bridged, diborane type geometries of ethanes is traced to a single molecular orbital, b2g or π* in symmetry. The energy of this orbital can be lowered, and the barrier to bridging accordingly decreased, by appropriately placed acceptor substituents. Low bridging barriers, relative to ethane, are predicted for cyclopentenyl cation, and cyano or nitro substituted ethanes.
Synthese der 2‐Methyl‐lysergsäure Eine neue Friedel‐Crafts‐Methode. 74. Mitteilung über Mutterkornalkaloide
Authors: Stütz P. , Stadler P. A. 
Published: December 2004

AbstractThe new reagent 2‐methoxy‐1,3‐dithiolane and cyclic ortho‐thioesters can be used in a new reaction of the Friedel‐Crafts type to introduce the corresponding aldehydic or ketonic thioacetal function directly into substrates containing an indole nucleus with free 2‐ or 3‐position.
Darstellung und spektroskopische Untersuchungen von Platinkomplexen, I. Interpretation der Spektren inverser Elektronentransfer‐ und Ligandenfeldübergänge von Platin (II)‐Komplexen mit Halogenid und Stickstoffliganden
Authors: Textor M. , Ludwig W. 
Published: December 2004

AbstractDas Auftreten von inversen Elektronentransfer‐Übergängen vom Typ d(M) → π* (L) in PtL2X2‐Komplexen mit Liganden, die ein L‐internes π‐Elektronensystem haben, wird nachgewiesen. Eine Unterscheidung von den normalen Elektronentransferübergängen aus dem Halogenidsystem X → M ist bei diesen Komplexen sowohl bei D2h‐ wie bei C2v‐Symmetrie ausnahmslos möglich. Insbesondere wird gezeigt, dass bei dieser Verbindungsreihe eine quantitative Korrelierung der Energien von Ligandenfeld‐ und inversen Elektronentransferübergängen möglich ist, die eine Zuordnung der einzelnen Banden mit hohem Wahrscheinlichkeitsgrad erlaubt. Die weitaus besten Resultate der Korrelation werden erhalten für eine Zufallsentartung der «d»‐ Orbitale xy, xz und yz bei D2h‐ bzw. 2z2‐x2‐y2, xz und xy bei C2v‐Symmetrie. Nur ein einziges der in den d8‐Systemen besetzten «d»‐Orbitale ist demnach deutlich stabiler, 2z2–x2–y2 in D2h und x2–y2 in C2v, so dass jeweils nur zwei spinerlaubte Ligandenfeldbanden beobachtet werden können.
Stoffwechselprodukte von Mikroorganismen. 101. Mitteilung. Synthese der trans‐5‐Hydroxy‐3‐methylpenten‐(2)‐säure (trans‐Δ2‐Anhydromevalonsäure)
Authors: Keller‐Schierlein W. , Widmer J. , Maurer B. 
Published: December 2004

Abstracttrans‐Δ2‐Anhydromevalonic acid (XVII) was prepared by a Wittig reaction, starting from (4‐tetrahydro‐2‐pyranyloxy)‐2‐butanone. On the other hand, the corresponding 4‐acetoxy‐2‐butanone gave, under similar conditions, the cyclohexene derivative V, explainable by a twofold Michael addition of the Wittig reagent to methyl vinyl ketone, followed by an intramolecular alcol condensation.
Lokalisierte intermolekulare Induktionswechselwirkung endlicher Dipole mit apolaren Lösungsmittelmolekeln: Die Deutung temperaturabhängiger Dipolmomente von Carbonyl‐ und Thionderivaten der 1,2‐Dithiacyclopentene
Authors: Eicke H.‐F. , Christen H. 
Published: December 2004

AbstractSolute‐solvent interactions of the 1,2‐dithiacyclopentenones and the analogue dithiathiones with non‐polar solvent molecules as well as the formation of hetero‐association complexes of these compounds is attributed to localized electrostatic induction. The distribution of the electric field around the oxo and thiono groups, respectively, is of special importance in determining the strength of the association. The temperature dependent solute‐solvent interactions are correlated with changes in the observed dipole‐moments.A plausible quantitative model based on finite dipole‐moments is proposed in order to interpret the fundamental process of association.
Photoelectron Spektra of Azabenzenes and Azanaphthalenes: II. A Reinvestigation of Azanaphthalenes by High‐Resolution Photoelectron Spectroscopy
Authors: Brogli F. , Heilbronner E. , Kobayashi T. 
Published: December 2004

AbstractThe bands with Iv < 13 eV in the photoelectron spectra of quinoline (IX), isoquinoline (X), cinnoline (XI), quinazoline (XII), and quinoxaline (XIII) have been reassigned in a way consistent with the assignment proposed for pyridine (II), the diazines (III, IV, V), s‐triazine (VI), and 1,2,4,5‐tetrazine (VII). The bands corresponding to the ejection of an electron from a π‐orbital have been identified by a regression calculation based on a HMO perturbation treatment. It has been found that the combined through‐space and through‐bond interaction of the lone pairs in III, IV, V and in their corresponding benzologues XI, XII, XIII are the same within experimental error ( ±, 0.2 eV). Our assignment is also supported by an empirical correlation of the pKa, 1− values and the mean lone‐pair ionization potentials of the azaderivatives I to XIII.
Über die Synthese der Pilocarpus‐Alkaloide Isopilosin und Pilocarpin, sowie die absolute Konfiguration des (+)‐Isopilosins
Authors: Link H. , Bernauer Karl 
Published: December 2004

AbstractA novel synthesis for rac‐pilosinine (6 rac) and transformation of (+)‐pilosinine (6) into the pilocarpus alkaloids (+)‐isopilosine (9) and (+)‐pilocarpine (18) are described. By correlation via 5 with 18 the absolute configuration of (+)‐isopilosine (9) is established.
Zur Reaktionsweise von Enaminen mit Cyclopropenonen II
Authors: Bilinski V. , Steinfels M. A. , Dreiding A. S. 
Published: December 2004

AbstractThe addition of diphenylcyclopropenone 2 to several enamines 1 as described by Ciabattoni & Berchtold [1] [2] has been reinvestigated. The products which were previously postulated to be enamines of β‐dicarbonylcompounds 9 to 14 have now been shown to be ‘amides’ 16 to 20. The reaction does not take the course of a ‘C, C‐insertion’, which would have been useful for ring expansion, but rather of a ‘C, N‐insertion’, which attaches a C3 side chain to the α‐carbon of enamines. This conclusion was reached by new interpretations of spectral data and by chemical transformations of old and new products. In the course of this reinvestigation, a new class of products, the amino‐cyclopentenones 41, 45 and 47, were isolated from the enamine‐cyclopro‐penone‐reaction. Their structures were proven by spectroscopic considerations and by chemical degradation.A systematic representation of these reactions is proposed in the reaction scheme.
The Synthesis and Some Reactions of N‐Alkyl‐4‐Quinolone‐3‐Carboxylic Acids
Authors: Markees D. G. , Schwab Linda S. 
Published: December 2004

AbstractA modification of the Gould‐Jacobs reaction, particularly useful for the preparation of N‐alkyl‐4‐quinolone‐3‐carboxylic acids, is described. Decarboxylation of these acids leads to N‐alkyl‐4‐quinolones or, in the case of N‐ethyl‐benzo[h]‐4‐quinolone‐3‐carboxylic acid, to 4‐ethoxy‐benzo[h]quinoline. Evidence for the structure of the products is presented and the synthesis of relevant compounds is described.