bluuebunny/crossref_metadata_2025_split huggingface dataset:
Die Kinetik der Spaltung dinuklearer Tri‐μ‐hydroxo‐kobalt(III)‐Komplexe N3Co(Oh)3CoN33+ (triole) mit Säure
Authors: Kähler Hans C. , Geier Gerhard , Schwarzenbach Gerold 
Published: December 2004

AbstractThe kinetics of formation of dinuclear di‐μ‐hydroxo‐diaquo‐bis‐cobalt(III) complexes from the corresponding tri‐μ‐hydroxo complexes:

equation image

has been investigated with three different compounds to start with: Ammonia‐Triol [N3 = (NH3)3], Dien‐Triol [N3 = H2N—CH2—CH2—NH—CH2—CH2—NH2] and Tach‐Triol [N3 = C6H9(NH2)3 = cis‐cis‐1,3,5‐triaminocyclohexane]. With respect to the otherwise very inert cobalt(III)‐complexes, reaction (1) is unusually rapid and takes place in two steps, the first being about 100 times faster than the second. The process begins with an exceptionally slow proton transfer to one of the bridging OH with half life of 0,2, 0,03 and 0,025 sec. respectively (perchlorate medium μ 1 M, 20°, pH = 0). The rate of the back reaction could also be determined, yielding ratios of the two rate constants corresponding to pK‐values between 0 and 1,5. Whereas Tach‐Triol is protonated to the di‐μ‐hydroxo‐μ‐aquo complex at about pH 1, it is deprotonated to the di‐μ‐hydroxo‐μ‐oxo complex at about pH 14 (Siroky [16]). The second step of (1), the aquation of the di‐μ‐hydroxo‐μ‐aquo species to the di‐μ‐hydroxo‐diaquo complex (Diol) takes place with half lives between 4 and 9 sec.The final cleavage to the mononuclear triaquo complex needs many hours to go half way and is again initiated by protonation of one of the remaining two OH‐bridges. Neither the μ‐aquo complex produced thereby, nor the Mono‐ol [mono‐μ‐hydroxo‐tetraaquo complex] formed as an intermediate cause any observable changes of the spectrum. The Mono‐ol aquates at a rate which is inverse in [H+] because of the labilisation brought about by deprotonation of its aquo ligands.
Model Calculations on the Squalene Cyclization
Authors: Gleiter Rolf , Müllen Klaus 
Published: December 2004

AbstractAs a model for the squalene cyclization the interaction between a methyl cation or a methyl radical and two double bonds has been studied using the CNDO/2 and INDO method. In both cases bond formation between the CH3‐group and one double bond is facilitated by a second one, but not in a concerted way.
Weitreichende Kopplung zwischen Protonen und Fluor in 2‐Fluorbenzamiden
Authors: Fritz Hans , Winkler Tammo 
Published: December 2004

AbstractLarge ‘through space’ hydrogen‐fluorine coupling has been observed in 2‐fluorobenzamides (5JHF = 10 to 16 Hz). The solvent dependence of the coupling shows that nuclear spin information is transmitted via hydrogen bonds.
Synthèses dans la série des bis‐indéno‐fluorènes, VIII. Méthyl‐6‐dihydro‐9,15‐7H‐bis‐indéno[2.1‐b;2′.1′‐g]fluorène
Authors: Chardonnens Louis , Stauner Thomas 
Published: December 2004

AbstractStarting from 5‐benzoyl‐2,4‐dibromobenzoic acid and 3‐methyl‐fluorene, the 6‐methyl‐9,15‐dihydro‐7H‐diindeno[2.1‐b; 2′,1′‐g]fluorene, a derivative of a mono‐angular diindenofluorene has been synthesized in 5 steps (overall yield 1,5%).
Isolement et identification des hydrocarbures sesquiterpéniques de l'huile essentielle de graines d'Anis
Authors: Tabacchi Raffaele , Garnero Jean , Buil Pierre 
Published: December 2004

AbstractThree sesquiterpenes: β‐farnesene (I), γ‐himachalene (II) and ar‐curcumene (III) have been isolated from the title essential oil. The determination of the structure of γ‐himachalene and his 13C‐NMR. spectrum are described.
Rhodium‐Katalysierte Isomerisierungen von 2‐Methylidenglutarsäureestern zu Methylglutaconsäureestern
Authors: Weis Claus D. , Winkler Tammo 
Published: December 2004

AbstractThe Rhodium(III)‐catalyzed thermal isomerization of 2‐methylidenglutaric acid esters affords predominantly mixtures of cis/trans‐2‐methylglutaconic acid esters (2, 3) which upon slow distillation isomerize completely into the cis‐esters (2). Saponification of 2 yields trans‐2‐methylglutaconic acid (5). Attempts to prepare the acid chloride of 5 produces 6‐chloro‐5‐methylpyrone‐2 (9) or 6‐chloro‐3‐methylpyrone‐2 (10) which react with anilines to N‐substituted derivatives of trans‐4‐methylglutaconic acid amides (11). The thermal isomerizations of the respective esters are discussed in terms of 1,5‐hydrogen shifts in their ester enol structures.
Photochemische Reaktionen. 76.Mitteilung [1]. UV.‐Bestrahlung von 11‐Oxo‐Steroiden V Die Photoisomerisierung von 3,20‐Diäthylendioxy‐5α,14β,17α‐pregnan
Authors: Gull Peter , Saito Yoshihisa , Wehrli Hansuli , Jeger Oskar 
Published: December 2004

AbstractThe UV.‐isomerisation of 11‐oxo‐14β,17α‐pregnane 9 to the 11,19‐cyclo‐derivative 11 is described. In addition the Pb(OAc)4‐fragmentation of photoproduct 11 was investigated. 11 yielded besides the expected 11‐oxo‐19‐hydroxy‐pregnane 18 the novel 9,11‐seco‐11,19‐cyclosteroid 19. The structure of 19 was established by chemical transformations and subsequently confirmed by X‐ray analysis [2].
Oxydative Kupplung von Indolinen und 1,2,3,4‐Tetrahydrochinolinen mit Kaliumpermanganat. 153. Mitteilung über Alkaloide
Authors: Rosenkranz Hans Jürgen , Winkler‐Lardelli Barbara , Hansen Hans‐Jürgen , Schmid Hans 
Published: December 2004

AbstractIt is shown that treatment of indolines like 4a‐methyl‐1,2,3,4,4a,9a‐hexahydrocarbazole (1) and even indoline‐alkaloids like 5 or 6 (cf. scheme 1) with KMnO4 in boiling acetone solution leads to the indolenines 10, 29 and 33, respectively, and, in relatively high yields, to N,N′‐ or C,N‐coupling products (cf. schemes 2 and 5). The results of the oxidation of 6‐ or 8‐methoxy‐indolines are shown in schemes 3 and 4, respectively. Analogous ‘dimeric’ dehydrogenation products are observed when tetrahydroquinolines (8 and 9, resp.) are treated with KMnO4 (cf. schemes 7 and 8, resp.).The formation of the bis‐compounds is almost certainly due to the coupling of two intermediate indolenyl or tetrahydroquinolyl radicals.The cleavage of the hydrazine derivatives 11 or 17 (scheme 9) also leads to ‘dimeric’ C,N‐coupling products.By heating the hydrazine derivative 17 with aqueous HCl, a complete cleavage into indoline 2 and the indolenines 16 and 20 is observed. The reaction is rationalized in scheme 10.So far no naturally occurring alkaloids related to the above mentioned C,N‐coupling products have been found.
Bicyclo[4. 1. 0]hept‐3‐ene‐2, 5‐dione (homo‐p‐quinone) and its bamford stevens reaction
Authors: Chapleo Christopher B. , Dreiding André S. 
Published: December 2004

AbstractHomo‐p‐chinon (4 = Bicyclo[4.1.0]hept‐3‐en‐2,5‐dion) wurde hergestellt und auf seine Spektraleigenschaften untersucht. Die UV.‐, IR.‐ und NMR.‐Spektren sind charakteristisch für die darin enthaltene Endion‐und cis‐disubstituierte Cyclopropan‐Substruktur, ohne eine starke Wechselwirkung zwischen den beiden zum Ausdruck zu bringen.Basische Thermolyse des Bis‐p‐toluolsulfonylhydrazons (9) von Homo‐p‐chinon ergab das bekannte 1,7 a‐Diaza‐inden (10). Dies bestätigt den früher postulierten Mechanismus der Bamford‐Stevens‐Reaktion mit den zwei isomeren Bis‐homo‐p‐chinonen (1a und 2a).
An Investigation of the Tea Aroma. Part I. New volatile black tea constituents
Authors: Renold Walter , Näf‐Müller Regula , Keller Urs , Willhalm Bruno , Ohloff Günther 
Published: December 2004

AbstractA total of 68 constitutents, mainly aldehydes, ketones and esters, have been identified for the first time in a black tea aroma concentrate using coupled gas‐chromatography/mass spectrometry.
Regiospecific Acylation, Alkylation, and Aldol Condensation using magnesium enolates resulting from the conjugate addition of grignard reagents to α, β‐unsaturated ketones
Authors: Näf Ferdinand , Decorzant René 
Published: December 2004

AbstractThe magnesium 3,3‐dimethylcyclohex‐1‐enolate 1i, formed in the copper catalyzed addition of methylmagnesium iodide to 3‐methylcyclohex‐2‐enone, has been subjected to regiospecific electrophilic reactions such as acylation, alkylation, and aldol condensation in order to find a new access to the damascones, ionones and carotenoids. By way of illustration a new synthesis of γ‐damascone is described.
Biosynthesis of the Verrucarins and Roridins. Part 1. The transformation of mevalonic acid into verrucarinic acid. Evidence for a hydrogen 1,2‐shift. Verrucarins and roridins, 27th communication
Authors: Achini Roland , Müller Beat , Tamm Christoph 
Published: December 2004

AbstractIncorporation experiments using sodium [2‐14C]‐, [2‐3H]‐, (3R)‐[5‐14C]‐ and [2‐3H, 2‐14C]‐mevalonates and with mevalonates stereospecifically tritiated at C(2) demonstrate the transformation of mevalonic acid (8) into verrucarinic acid (5). Degradation experiments showed that this transformation occurs with a hydrogen 1, 2‐shift of the ‘pro‐2R’ hydrogen atom of mevalonate to C(3) of verrucarinate. A possible mechanistic pathway is discussed.
Structure cristalline et moléculaire d'un dérivé méthyl‐hexopyranoside à C(4) hybridé sp2
Authors: Bernardinelli Gérald , Gerdil Raymond 
Published: December 2004

AbstractThe derivative C13H19NO5 crystallizes in space group P212121 with a = 9.371, b = 11.815, c = 13.207 Å and Z = 4. The structure was solved by direct methods and refined by full‐matrix least‐squares to R = 0.058. The pyranose ring exists in the 3S1 conformation (or in the equivalent, but here structurally less consistent, 0S4 conformation). The dioxolane ring has an envelope conformation. Strong intramolecular interactions between the bulky substituents suggest that the ensuing strain energy is assumed, for a significant part, by the twisted‐boat conformation of the pyranose ring.
Fluorénacènes et fluorénaphènes Synthèses dans la série des indéno‐fluorènes, XVIII. Le diméthyl‐5, 6‐dihydro‐7, 12‐indéno[1, 2‐a]fluorène
Authors: Chardonnens Louis , Häger Josef 
Published: December 2004

AbstractStarting from 3, 4‐dimethylfluorene the title compound, 5, 6‐dimethyl‐7, 12‐dihydro‐indeno[1,2‐a]fluorene (IV), is synthesized in four steps (overall yield 9%). The same hydrocarbon is also obtained in four steps starting from the phthalaconecarboxylic acid of Gabriel. This corroborates the structure of IV.
1, 6‐Addition von Chlorsulfonylisocyanat. Vorläufige Mitteilung
Authors: Fischli Albert , Mayer Hans , Oberhänsli Willi 
Published: December 2004

AbstractA 1, 6‐addition of sulfonyl chloride isocyanate to 5, 7‐dimethyl‐8‐methylidene‐tricyclo[3.2.1.02,7]oct‐3‐en‐6‐one (1) produced the new tricyclic skeleton of 4a, 6‐dimethyl‐2, 5‐dioxo‐2, 3, 4a, 5, 6, 8a‐hexahydro‐1H‐6, 4‐methenoquinoline‐1‐sulfonyl chloride (2). The structure of the new aza‐tricyclic species has been elucidated by X‐ray analysis.
Reaction Rates of t‐Butyl and Pivaloyl Radicals in Solution
Authors: Schuh Hans , Hamilton Edwin J. , Paul Henning , Fischer Hanns 
Published: December 2004

AbstractThe rate constants of the unimolecular decomposition of the pivaloyl radical (kD) and of the bimolecular self terminations of pivaloyl (k1) and t‐butyl radicals (k2) in liquid methylcyclopentane are determined by ESR.‐spectroscopy:
equation image
The viscosity dependence of (k2) is analysed with respect to diffusion control of the reaction. Comparison of (kD) values of different acyl radicals reveals a strong dependence of the activation energies on radical structure.
Terpenoids Derived from Linalyl Oxide. Part 1. The stereochemistry of the davanones
Authors: Thomas Alan F. , Thommen Walter , Willhalm Bruno , Hagaman Edward W. , Wenkert Ernest 
Published: December 2004

AbstractNatural (+)‐davanone is 6S,7S,10R‐2,6,10‐trimethyl‐7,10‐oxidododeca‐2,11‐dien‐5‐one (1). Equilibration of davanone with base leads to the four possible isomers, but only a single deuterium atom is exchanged when deuterium oxide is the solvent.
Terpenoids Derived from Linalyl Oxide. Part 5. 2‐(2‐Methyl‐2‐vinyltetrahydrofur‐5‐yl)‐2,6,6‐trimethyl‐2,6‐dihydropyr‐3‐one, a new sesquiterpenoid isolated from Artemisia Pallens
Authors: Thomas Alan F. 
Published: December 2004

AbstractBased on spectra, the structure of the title compound has been attributed to a new sesquiterpenoid isolated from Artemisia Pallens. From the same fraction of the oil, the conjugated unsaturated ketone, isodavanone (2), was identified.
Novel Synthesis of 3,5,5‐Trimethyl‐4‐(2‐butenylidene)‐cyclohex‐2‐en‐1‐one, a Major Constituent of Burley Tobacco Flavour
Authors: Demole Edouard , Enggist Paul 
Published: December 2004

AbstractThe acetylenic diol 2, prepared by reaction of but‐3‐yn‐2‐ol dianion with 2,6,6‐trimethyl‐4,4‐ethylenedioxy‐cyclohex‐2‐en‐1‐one (1), afforded 3,5,5‐trimethyl‐4‐(2‐butenylidene)‐cyclohex‐2‐en‐1‐one (4), a major constituent of Burley tobacco flavour, upon LiAlH4 reduction and hydrolysis. Vomifoliol (5) and blumenol C (6) were major by‐products in this reaction.
The Photochemical Behavior of Endocyclic Oxa‐enones with Substituents on the CC Double Bond. (Preliminary communication)
Authors: Margaretha Paul 
Published: December 2004

AbstractAlkyl substituents on Cβ of the CC double bond hinder both photodimerization of endocyclic oxa‐enones (1–4) and their photocycloaddition to olefins, and they cause a loss of regiospecificity in dimerization in unpolar solvents. The oxa‐enone 3 which like the bicyclic compounds 4 fails to dimerize at all, is shown to incorporate deuterium at the tertiary isopropyl carbon atom in CD3OD solution as a consequence of a bimolecularly initiated photoenolization.
The Stabilization Energy of [18] Annulene. A thermochemical determination
Authors: Oth Jean F. M. , Bünzli Jean‐Claude , de Julien de Zélicourt Yves 
Published: December 2004

AbstractThe thermal rearrangement of [18]annulene in solution gives benzene and 1,2‐benzo‐1,3,7‐cyclooctatriene. This reaction has been investigated using a differential scanning calorimeter and the associated enthalpy change has been measured. The enthalpy of the reaction (in the gase phase at 298°K) is

From this value and the enthalpies of formation of the reaction products, the enthalpy of formation of [18]annulene is obtained:

The stabilization energy of [18]annulene, defined as the difference between the enthalpy of formation of the hypothetical Kékulé [18]annulene (with single and double bonds of normal lengths) and the heat of formation of the real molecule is then

a value close to the corresponding quantity found for benzene.The very large stabilization energy of [18]annulen (100 ± 6 kcal mol−1) previously reported in the literature, based on measurements of the heat of combustion, is not correct since the annulene is certainly oxidized in the bomb prior to combustion.The isodynamic conformational mobility of [18]annulene is not incompatible with a stabilization energy of 37 kcal mol−1; the activation enthalpy observed for this process (ΔH≠ = 16.1 kcal mol−1) indicates that the stabilization is not completely destroyed in the transition state.The mechanism of the thermolysis of [18]annulen, investigated by kinetic measurements and by analysis of the shape of the thermograms, is discussed.
The ionization energies of bridged [14]annulenes and of dicyclohepta[cd, gh] pentalene
Authors: Batich Christopher , Heilbronner Edgar , Vogel Emanuel 
Published: December 2004

AbstractThe ionization energies JJ, of 1,6;8,13‐alkanediylidene‐[14]annulenes (2 to 5) and of dicyclohepta[cd,gh]pentalene (1) have been determined by photoelectron spectroscopy, using HeI radiation. The data are interpreted in terms of Koopmans' theorem (JJ = −εJ) on the basis of correlation diagrams and with the help of simple molecular orbital models.If the bridge is an ethane‐, propane‐ or butane‐diylidene group, the π‐orbital sequence, in descending order of orbital energies, is (in C2v): b1, b2, a2, a1. The sequence is due to a complicated and not uniquely definable interplay of inductive, conjugative and homoconjugative effects. A detailed analysis of these effects suggests that the effective angle of twist between two consecutive basis‐AOs 2pμ, 2pν of the peripheral π‐system should be smaller than the twist angles θμν determined by X‐ray analysis, i.e. that the pi;‐ribbon adjusts elastically and is no longer locally orthogonal to the σ‐frame.In the non‐alternant hydrocarbon 1 of symmetry D2h, the sequence is 2b2g, 3b1u, 2b3g, 1au, 2b1u. The sequence 3b1u above 2b3g, i.e. the reverse of b2 above a1 in the bridged [14]annulenes, is explained as being due to the interaction of the semilocalized perimeter orbitals b1u and b3g with the bonding (π(B1u))and antibonding (π*(B3g)) orbital of the central double bond. In 2 the replacement of the two latter orbitals by the Walsh‐orbitals of the cyclopropane moiety leads to the sequence b1, b2, a1, a2.From the data observed for 1 to 5 and for 1,6‐methano‐[10]annulene [11], a crude estimate for the orbital energies of the hypothetical all‐cis D10h‐[10]‐ and D14h‐[14]annulenes can be derived.
Contribution à la phytochimie du genre Gentiana IX. Etude de composés flavoniques et xanthoniques dans les feuilles de gentiana CampestrisL. 1ère communication
Authors: Kaldas Maryse , Hostettmann Kurt , Jacot‐Guillarmod André 
Published: December 2004

AbstractTwo new xanthone‐O‐glycoside, the 1,3,5‐trihydroxy‐xanthone‐8‐O‐β‐D‐glucopyranoside (3), the 1,5‐dihydroxy‐3‐methoxyxanthone‐8‐O‐β‐D‐glucopyranoside (4), have been isolated from the leaves of Gentiana campestris L. by means of column chromatography on polyamid. Two known xanthones (1, 2) which are respectively the aglycones of 3 and 4 and a flavone: iso‐orientine (5) have also been isolated and identified.
Selektive Funktionalisierung von Polyenen
Authors: Kienzle Frank , Minder Rudolf E. 
Published: December 2004

AbstractThe possibility to functionalize selectively various polyenes using hydroboration or a Vilsmeyer‐type formylation was demonstrated. Reversible sulfur dioxide addition may be used in some cases to protect two double bonds in a polyene system. Reactions with mercuric acetate, thallium(III) nitrate, bromine or peracetic acid were found useful only in some cases for the selective introduction of functional groups.
Dérivés propargyliques, XII et dérivés de la décahydroquinoléine, II Alkynyl‐4, alkényl‐4 et alkyl‐4‐décahydroquinolinols‐4 N‐substitués
Authors: Prost Maurice , Urbain Marcel , Schumer André , Houben Christian , Van Meerbeeck Clément 
Published: December 2004

AbstractThe authors describe the synthesis of decahydro‐4‐quinolinones and N‐substituted 4‐alkynyl‐, 4‐allyl‐ and 4‐alkyldecahydro‐4‐quinolinols and discuss the stereochemical problems of this compounds.
Reaktionen an Allencarotinoiden 2
Authors: Buchecker Richard , Liaaen‐Jensen Synnøve 
Published: December 2004

AbstractThe conversion of the allenic end group 1 on HCl/CHCl3 treatment to the acetylenic 2 resp. to the chlorinated end group 3 previously reported has been confirmed using neoxanthin (4a) and its diacetate (4b). Analogous HBr treatment provided the corresponding brominated end group. Chemical and spectroscopical evidence for the position of the halogen atom at C(7) is given.Transformation to allenic anhydro products and acetylenic products on treatment of neoxanthin diacetate (4b) with phosphorous oxychloride in pyridine, as well as dehydration and chlorine substitution of neoxanthin (4a) are reported. These results are consistent with previous observations on related carotenoids.
Modellversuche in der Histrionicotoxinreihe Synthese des (±)‐cis‐1‐Azaspiro[5.5]undecan‐8‐ols
Authors: Gössinger Edda , Imhof René , Wehrli Hansuli 
Published: December 2004

AbstractAs a first step toward total synthesis of histrionicotoxin and its congeners, the preparation of (±)‐cis‐Azaspiro[5.5]undecan‐8‐ol (11) is described.
Farbstoffe aus der Bibenzyl‐Reihe
Authors: Manukian Badrig K. , Huber Walter , Glanzmann Ernst 
Published: December 2004

Abstract4,4′‐ und 2,2′‐Diaminobibenzyl wurden tetrazotiert und mit Acetessigsäure‐anilid bzw. Acetessigsäure‐2′,5′‐dimethoxy‐4′‐chlor‐anilid gekuppelt. Die erhaltenen Disazofarbstoffe, darunter X, färben Polyvinylchlorid grünlich‐gelb; X (Kopplungsprodukt aus tetrazotiertem 2,2′‐Diamino‐bibenzyl und 2 mol Acetessigsäure‐2′,5′‐dimethoxy‐4′‐chlor‐anilid) weist ähnliche Eigenschaften wie Pigment Yellow 83 auf. Vier Diaminobibenzyle, mit je 2 Mol.‐Äquiv. 1‐Chlor‐4‐nitro‐acridon umgesetzt, ergaben lineare Diacridone, die sich aber nicht zur Färbung von Weich‐PVC eignen.
Oscillations chimiques lors de l'oxydation de dicétones par le bromate en présence d'un catalyseur (Réaction du type Belousov‐Zhabotinsky)
Authors: Stroot Philippe , Janjic Désimir 
Published: December 2004

AbstractNew ketonic compounds have been found to generate temporal chemical oscillations in Belousov‐Zhabotinsky – type reactions: fluorinated acetylacetone, acetonylacetone (2,5 hexanedione) and, acetone itself.
The Reaction of Nitrosoalkane Dimers with Acid Halides
Authors: Ribi Max A. , White Emil H. 
Published: December 2004

AbstractNitrosoalkane dimers react with acid halides to yield α‐halogeno‐azoxy compounds with the substituent α to the oxygen‐bearing nitrogen. In the presence of silver carbonate, the corresponding α‐acyloxy‐azoxy compounds are formed.
Die Synthese von (−)‐ bzw. (+)‐threo‐3‐(3,4‐Dihydroxyphenyl)‐serin und (−)‐ bzw. (+)‐erythro‐3‐(3,4‐Dihydroxyphenyl)‐serin
Authors: Hegedüs Balthasar , Krassó Anna F. , Noack Klaus , Zeller Paul 
Published: December 2004

AbstractThe known synthesis of DL‐3‐(3,4‐dihydroxyphenyl)‐serine (DOPS) has been modified so that the diastereomeric threo and erythro forms could be separated. These were resolved into their antipodes, whose chemical, physical, and spectrochemical properties are discussed.
Photochemical Cyclization of Allylated Anisole and N‐Alkyl Aniline Derivatives. Preliminary communication
Authors: Koch‐Pomeranz Ursula , Hansen Hans‐Jürgen , Schmid Hans 
Published: December 2004

AbstractThe allyl anisole derivatives 1, d2‐1, 3, 5 and 7 (Scheme 1), on exposure to UV. light in benzene, acetone or methanol solution, cyclize to yield the corresponding cyclopropyl anisole derivatives 2, d2‐2, cis‐ and trans‐4, 6 and 8, respectively. Under the above conditions the N, N‐dialkyl‐2‐allyl anilines 9, 10 and 11 give similar results (Scheme 2). On the other hand, N‐alkyl‐2‐allyl anilines (15 and 19, Scheme 3) are transformed by UV. light in cyclohexane or benzene solution into 2‐methyl‐indolines (16 and 20, resp.), whereas in methanol solution the corresponding 2′‐methoxy compounds 18 and 21 are formed in addition to 16 and 20, respectively.
Über die Oxydation des O‐Methylbulbocapnins mit Jod
Authors: Gerecke Max , Borer René , Brossi Arnold 
Published: December 2004

AbstractThe oxidation product obtained by treatment of bulbocapnine methyl ether (2a) with iodine in ethanol/water is not the tetradehydroaporphinium salt 4 as assigned by Gadamer & Kuntze, but a dimer of structure 3. Reduction of 3 with zinc in dilute sulfuric acid gives rac‐bulbocapnine methyl ether, whereas reduction with complex hydrides affords the diastereomeric dimers 7a and 7b.
Crustaxanthin‐tetraacetat und weitere Tetraester des Crustaxanthins
Authors: Kienzle Frank , Hodler Martin 
Published: December 2004

AbstractIt is shown that the acetylation of synthetic crustaxanthin with acetic anhydride in pyridine yields the tetraacetate and not the diacetate as claimed. Even more voluminous reagents such as bis‐trimethylsilylacetamide, pivaloyl or 1‐adamantoyl chloride give rise to tetraester. The identification of these derivatives was accomplished through spectral data.
The Structure of Discretamine, a Tetrahydroprotoberberine Alkaloid
Authors: Richter Wilhelm J. , Brochmann‐Hanssen Einar 
Published: December 2004

AbstractOn the basis of mass spectrometric analysis, including comparison with closely related isomers, discretamine is proposed to have the structure of a 3,10‐dihydroxy‐2,9‐dimethoxytetrahydroprotoberberine.