bluuebunny/crossref_metadata_2025_split huggingface dataset:
Neue Bifunktionelle Brückenfunktionen zur A1‐B29‐Verklammerung der beiden Insulinketten
Authors: Losse Günter , Naumann Wolfgang , Mätzler Gudrun , Richter Birgit 
Published: December 2004

Novel Bifunctional Bridging Functions for A1‐B29 Crosslinking of the Two Insulin ChainsThe positions A1 and B29 of the insulin molecule are crosslinked by the new bifunctional groups U and V. These insulin derivatives are convertible by oxydative sulfitolysis into A1‐B29 crosslinked hexa‐S‐sulfonates, which recombine by tributylphosphan/O2 in high yields to the A1‐B29 insulin derivatives, correctly reconstructing the disulfide system, and from which the bridging function is smoothly removable by acidolysis. The example of the bridging function U demonstrates that this principle is also suitable for the combination of both isolated single chains.
Tetrathiafulvalene. XVIII. Elektronen‐Donator‐Akzeptor‐Komplexe von Tetrathiafulvalenen (TTF) mit Tetracyanochinodimethan (TCNQ)
Authors: Schukat G. , Fanghänel E. 
Published: December 2004

Tetrathiafulvalenes. XVIII. Charge‐Transfer‐Complexes of Tetrathiafulvalenes (TTF) with Tetracyanoquinodimethane (TCNQ)TTF form CT‐complexes with TCNQ in solvents having small ET‐values, whose association constants are estimated. The energy of the absorption maximum of the CT‐complex between octamethylentetrathiafulvalene and TCNQ increases linearly with decreasing ET‐values of the solvents. In chloroform the energy of the absorption maximum of the CT‐complexes between TCNQ and tetrathiafulvalenes increases linearly with the oxidation potential of the tetrathiafulvalene.
Dreikomponentenreaktionen. XIV. 2‐Imidazoline und 1,2,4‐Triazole durch Ringschlußreaktionen von N‐(2‐Chlor‐alkyl)imidchloriden mit Hydrazin und Hydrazonen
Authors: Neumann R. , Beger J. 
Published: December 2004

Three Component Reactions. XIV. 2‐Imidazolines and 1,2,4‐Triazoles by Ring Closure Reactions of N‐(2‐Chloro‐alkyl)imidchlorides with Hydrazine and HydrazonesN‐(2‐Chloro‐alkyl)benzimidchlorides (1a and 1b) give with hydrazine in dependence on the reaction medium 1,1′‐bis(2‐imidazolines) (4), 1‐benzamido‐2‐imidazolines (5) or 1,2,4‐triazoles (6 and 7) and also N‐(2‐chloro‐alkyl)benzamides (8). From imidchlorides (1a–c) and hydrazones Schiff bases (10) of 1‐amino‐2‐imidazolines are obtained. They are not cleavable into free 1‐amino‐2‐imidazolines. magnified image
The aminolysis of carbamates. II. The Kinetics and Mechanism of the Aminolysis of Benzyl N‐phenylcarbamate with ethanolamine in aprotic solvents
Authors: Löcsei Vasile , Facsko Otilia , Chirilâ Traian 
Published: December 2004

Aminolyse von Urethanen. II. Kinetik und Mechanismus der Aminolyse des Benzyl N‐phenylurethans mit Monoethanolamin in aprotischen LösungsmittelnDie Kinetik der Aminolyse des Benzyl‐N‐phenylurethans in Gegenwart eines Überschusses an Monoethanolamin wurde zwischen 140–160°C in zwei aprotischen Lösungsmitteln (Amin und Ether) verfolgt.Es werden komplexe Geschwindigkeitsgesetze der Form kexp. = k Amin + k' Amin2 gefunden und mit einem E1cB‐Verlauf der Aminolysereaktion interpretiert. Ein synchroner E‐A‐Mechanismus unter Zwischenbildung eines Isocyanats wird dadurch ausgeschlossen, da die N‐methylierte Verbindung nicht reagiert.
Über Gesetzmäßigkeiten in der π‐Elektronenstruktur von heteroanalogen Polyvinylidenverbindungen
Authors: Hartmann Horst , Gutman Ivan 
Published: December 2004

On Regularities of the π‐Electronic Structure of Heteroanalogous Polyvinylidene CompoundsStarting with simple forms of the equations for the eigenvalues and eigencoefficients of the π‐system of heteroanalogous polyvinylidene compounds 3 several regularities in the π‐electronic structure of these systems are derived and compared with known experimental facts. In this line several predictions are given for the properties of compounds unknown up to now.
Partialsynthesen von Cardenoliden und Cardenolid‐Analogen. VI. (20R)‐ und (20S)‐Cardanolide
Authors: Lindig Claus , Repke Kurt R. H. 
Published: December 2004

Partial Syntheses of Cardenolides and Cardenolide Analogues. VI. (20R)‐ and (20S)‐Cardanolides(20R)‐Dihydrodigitoxigenin (2) and (20S)‐dihydrodigitoxigenin (4) as well as their 3‐acetates3and5, respectively, were synthesized by catalytic hydrogenation of the appropriate cardenolides and separation by column chromatography on silica of the mixtures of stereoisomers. Hydroxymethylation of3and5followed by selective elimination yielded (20S)‐ and (20R)‐14‐hydroxy‐22‐methylene‐5β,14β‐cardanolide 3‐acetate (10and16), respectively.The biological activities of the synthesized 20‐stereoisomeric cardanolides are investigated and discussed. Cardanolides10and16have a strong inhibitory activity on the proliferation of Ehrlich ascites carcinoma cells in suspension culture.
Partialsynthesen von Cardenoliden und Cardenolid‐Analogen. VII. Synthese A/B‐cis‐ und C/D‐cis‐verknüpfter Steroidmono‐ und ‐bis(α‐methylen‐γ‐butyrolactone)
Authors: Lindig Claus 
Published: December 2004

Partial Syntheses of Cardenolides and Cardenolide Analogues. VII. Synthesis of A/B‐cis‐ and C/D‐cis‐linked Steroidal Mono‐ and Bis (α‐methylene‐γ‐butyrolactones)The synthesis of A/B‐cis‐ and C/D‐cis‐linked steroidal mono‐ and bis(α‐methylene‐γ‐butyrolactones) 10–13, 18 and 24 by Reformatsky‐type reaction of 3β‐acetoxy‐14‐hydroxy‐5β, 14β‐androstan‐17‐one( 6), 14‐hydroxy‐5β, 14β‐androstane‐3,17‐dione (8), 3β‐acetoxy‐14‐hydroxy‐5β,14β‐pregnan‐20‐one (17) and 14‐hydroxy‐5β,14β‐pregnane‐3,20‐dione (23), respectively, with ethyl α‐(bromomethyl)acrylate is described. All steroidal lactones exhibit strong inhibitory activity on the proliferation of Ehrlich ascites carcinoma cells in suspension culture. For inhibitory activity the lactone moiety at C‐17 of the steroid molecule is more important than the lactone moiety at C–3 and C–20, respectively.
O‐ und N‐alkylsubstituierte 2‐(2′‐Hydroxyphenyl)‐benzimidazole und ‐1,3,4‐oxadiazole als Komplexbildner und Extraktionsmittel für Kupfer‐II‐ionen
Authors: Beger J. , Wagner G. , Uhlig E. , Dinjus U. 
Published: December 2004

AbstractO‐ and N‐Alkylsubstituted 2‐(2′‐Hydroxyphenyl)‐benzimidazoles and ‐1,3,4‐Oxadiazoles as Complexing and Extracting Agents for Copper‐II‐Ions2‐(2′‐Alkoxyphenyl)‐benzimidazoles1, 1‐alkyl‐2‐(2′‐hydroxyphenyl)‐benzimidazoles2, 2‐(2′hydroxy‐4′‐alkoxyphenyl)‐benzimidazoles3, 2‐(2′,4′‐dialkoxyphenyl)‐benzimidazoles4and 1‐alkyl‐2‐(2′‐hydroxy‐5′‐nitrophenyl)‐benzimidazoles7are synthesized by condensation of 2‐hydroxybenzoic acid derivatives and o‐phenylenediamine or its derivatives. Alkyl chains C4, C8or C12are introduced by alkylation before or after the ring closure in order to increase the solubility of the reagent in toluene or n‐octane. Furthermore the extraction properties of the benzimidazoles are investigated. Also some new analogous compounds of the benzothiazole and the 1,3,4‐oxadiazole series were synthesized.
Dreikomponentenreaktionen. XVI Zur Halogenierung von Alk‐1‐enen in Gegenwart von Ethylenoxid und Propylenoxid
Authors: Beger J. , Schiefer H. , Scheller D. 
Published: December 2004

Three Component Reactions. XVI. Halogenation of Alk‐1‐enes in the Presence of Ethylene Oxide und Propylene OxideThe products of the chlorination of alk‐1‐enes in the presence of ethylene oxide and propylene oxide were investigated in relation to products of the chlorination in the presence of corresponding chloroalcohols4and5. Isomers dominating in the Markovnikov orientation were found in all cases. Two of the three pairs of diastereomeric bischloropropylethers expected for the chlorination of propene in the presence of propylene oxide were identified by capillar GLC and13C n.m.r. spectroscopy.
Untersuchung der Struktur photochemisch aus Pyrazolidon‐(3)‐azomethiniminen erzeugter 1,5‐Diaza‐bicyclo‐[3,1,0]‐hexan‐2‐one mit Hilfe der LIS und der RKSA
Authors: Geissler G. , Menz I. , Köppel H. , Kretschmer M. , Kulpe S. 
Published: December 2004

LIS and X‐Ray Investigations of the Structure of 1,5‐Diaza‐Bicyclo‐[3,1,0]‐hexanones‐(2) Obtained by Irradiation of Pyrazolidone‐(3)‐azomethineimines1,5‐Diaza‐bicyclo‐[3,1,0]‐hexanones‐(2) 2 are the photoproducts of pyrazolidone‐(3)‐azomethineimines 1. Generally they can exist in the exo‐form or in the endo‐form. 1H‐n.m.r.‐measurements of 2a–d show that neither at normal temperature (298 K) nor at low temperatures (213 K) an exo/endo mixture is formed photochemically. Therefore the conclusion is drawn that the photoreaction is stereospecific. Chemical shift calculations of the methyleneprotons and the methyl‐protons in 2c and 2d using the ring current model and lanthanoide induced shifts (LIS) on 2d with Eu(fod)3 show that in solution the photoproducts have the exo‐form. These results are in agreement with results of a single‐crystal X‐ray structure analysis on 2a.
Konfigurationsbestimmung von Steroiden mit Primärer und sekundärer Aminogruppe durch Messung des Circulardichroismus der Kupfer‐Succinimidat‐Komplexe
Authors: Balint A. , Kerek F. , Ponsold K. , Schönecker B. 
Published: December 2004

Configurational Assignment of Steroids with Primary and Secondary Amino Groups by CD Measurements of the Copper Succinimidate complexesThe CD spectra of the copper succinimidate complexes of 9 different steroids with a primary and 3 steroids with a secondary amino group were investigated. A good correlation between the sign of the Cotton effects in visible range and the chirality of the immediate neighbourhood of the nitrogen atom was observed. The results obey the earlier established octant rule for this chromophor.
MO‐LCAO‐Calculations on Polymethines. XXI. Electrono‐dative, electrono‐captive, and electrono‐ambident polymethine radicals
Authors: Fabian J. , Hartmann H. 
Published: December 2004

Abstract[N + 1]π‐polymethine radicals with nitrogen containing terminal groups (violenes) display electron transfer reactions. Modification of the simple chain structures results in distinct changes of the molecular electronegativity and, consequently, of the redox properties. Based on the formerly defined non‐bonding singly occupied MO (SOMO) of ideal polymethines, the various polymethine derivatives are classed into electrono‐dative and electrono‐captive polymethine radicals. Electrono‐dative radicals are prone to release electrons, whereas electrono‐captive radicals are prone to accept electrons. This classification reflects experimental results presented by HÜNIGand coworkers, which have been formerly discussed in terms of aromaticity rather than of MO theory. A third class of radicals embraces compounds in which the redox properties of the simple chain polymethine radicals are less changed upon structural modification. These radicals have been termed as electrono‐ambident radicals because they are both inclined to release and to accept an electron. HÜNIGand coworkers obviously found the first representatives of this series of radicals. Electronoambident radicals also encounter in VIEHE‐type radicals suggesting a more general definition of the latter ones.
Zur palladiumkatalysierten Isoprentelomerisierung in alkoholischen Medien und deren Folgereaktionen
Authors: Gaube W. , Stegemann H. 
Published: December 2004

Palladium‐Catalyzed Telomerization of Isoprene in Alcoholic Mediums and its Consecutive ReactionsThe telomerization of isoprene with methanol to give dimethyloctadienylmethylethers by palladium‐containing homogenous catalysts was investigated. It was found that the primary products of the catalysis undergo different consecutive reactions catalysed by the same catalytic systems. These reactions, i.e. isomerization, ether cleavage, interchange reaction and oligomerization were investigated in greater detail. A reaction scheme is developed and discussed.
Cyansäureester. 35. Über Bildung und Folgereaktionen von N‐Cyanatophthalimid. Neue spezifisch aktivierte und blockierte Isatosäurederivate
Authors: Martin Dieter , Nadolski Karin , Gründemann Egon 
Published: December 2004

Cyanic Acid Esters. 35. On Formation and Consecutive Reactions of N‐Cyanato Phthalimide. New Specifically Activated and Blocked Isatoic Acid DerivativesDepending on the reaction conditions N‐hydroxy‐phthalimide affords on treatment with cyanogen bromide via N‐cyanato phthalimide 2 the iminocarbonate 3 and isatoic acid derivatives 7 and 16. Both the latter react with nucleophiles as isatoic acid derivatives activated on the carboxylic group and protected on the carbamic group or vice versa, furnishing N,N‐bis alkoxycarbonyl anthranilic acid amides 9, N‐alkoxycarbonyl anthranilic acid amides 12, o‐alkoxycarbonyl phenyl ureas 17 and the benzotriazepin‐2,5‐dione 14. The structures of the new compounds are proved by 1H‐n.m.r. and 13C‐n.m.r. measurements as well as independent synthesis.
Vereinfachte synthetische Wege zum Cyclol‐System von Mutterkorn‐Peptidalkaloiden
Authors: Losse Günter , Strobel Jürgen 
Published: December 2004

Improved synthetic pathways to the cyclol system of ergot peptide alkaloids.As demonstrated in the case of N‐tert. butyloxycarbonylhydroxyglycine, N‐protected 2‐hydroxy‐2‐amino acids can be directly condensed with dipeptide esters to afford tripeptide derivatives, which are activated C‐terminally and transferred into the epimers (8) and (9) of the corresponding oxacyclols. These are separated in the usual manner into the aci and the naturally occuring configuration 2R:5S:10aS:10bS. Alternatively, the epimeric cyclols may be obtained by acylation of dipeptide lactams with 2‐tert. butyloxycarbonylamino‐2‐benzyloxy‐carboxylic acids, followed by hydrogenolytic debenzylation and cyclisation of the OH‐deprotected acyl lactam.
Synthesis of Gonadoliberin, a gonadotropin releasing hormone
Authors: Rzeszotarska Barbara , Masiukiewicz Elzbieta , Kmiecik‐Chmura Halina 
Published: December 2004

AbstractA simple laboratory synthesis of gonadoliberin was elaborated basing on classical solution methods and using minimal protection of side‐chain functions. In the final step a hexapeptide segment was condensed with the corresponding tetrapeptide and the obtained product was purified by a single step silica gel chromatography. The total efficiency of the whole synthesis was 15%.
Pyryliumverbindungen, XXV. Quantenchemische Berechnungen zur Valenzisomerisierung von 2‐Amino‐2H‐pyran und ‐thiopyran
Authors: Schlodder Heike , Thieme Rainer , Weiss Cornelius , Fischer Gerhard W. , Zimmermann Thomas 
Published: December 2004

Pyrylium Compounds. XXV. Quantum Chemical Calculations Concerning the Valence Isomerization of 2‐Amino‐2H‐pyran and ‐thiopyranThe equilibrium 2‐amino‐2H‐pyran6⇌ 5‐amino‐2,4‐dien‐1‐one7was investigated using the semi‐empirical MINDO/3 and MNDO methods. In accordance with experimental findings for the substituted derivatives1/2a–d, the introduction of a methyl group into the position 3 of6or the exchange of oxygen by sulfur shifts the equilibrium towards the cyclic structures8and10, respectively. Polar solvents, the influence of which was estimated applying the reaction field approach as well as the solvaton theory, and entropy effects are calculated to favour the ring‐open valence isomer7. These results also correspond to experimental results.
Zur Pyrolyse unsubstituierter Cyclane – Produktbildungsselektivitäten, kinetische Parameter, mechanistische Interpretationen
Authors: Zimmermann G. , Zychlinski W. , Bach G. , Rennecke D. 
Published: December 2004

On the Pyrolysis of Unsubstituted Cyclanes – Selectivity of the Formation of Reaction Products, Kinetic Parameters, Mechanistic InterpretationsThe thermal decompostion of cyclopentane (1), cyclohexane (2), cycloheptane (3), cyclooctane (4), cyclodecane (5), and cyclododecane (6) was studied in a laboratoryscale metallic tubular reactor at 650 to 850°C in the presence of steam. The kinetic parameters for the overall reactions were determined and the gaseous as well as the liquid reaction products were analyzed and identified by gas chromatography or by the coupling of gas chromatography and mass spectrometry, respectively. It could be shown that from all cyclanes the isomeric α‐olefines are formed, if the conversion of the starting cyclanes is small. This supports the view that the cyclane → α‐olefin isomerization is an important initial reaction in pyrolysis of 1 up to 6. The results also demonstrate that the main pathway of degradation is a radical chain mechanism via cyclanyl radicals with β(CC) bond scission and 1.4 or 1.5‐H‐isomerization of alkenyl radicals as the most important reaction steps.
Eine neue Synthese von 4,5‐Dihydroxy‐pyrazolen
Authors: Kirschke Klaus , Schmitz Ernst 
Published: December 2004

A New Synthesis of 4,5‐Dihydroxy‐pyrazoles1‐Aryl‐pyrazolin‐5‐ones 1 are converted by Knoevenagel condensation with acetone or by reaction with 2,2‐dimethyl‐1,3‐dioxolane 6 to 1‐aryl‐4‐isopropyliden‐pyrazolin‐5‐ones 2. The compounds 2 are epoxidized by hydrogen peroxide forming the spiro‐epoxides 3, which can be cleaved to 4,5‐dihydroxy‐pyrazoles 4 under acidic conditions. 4‐Acetoxy‐5‐hydroxy‐pyrazoles 13 are formed directly, when 3 are cleaved in presence of acetic anhydride. The 3,3′,3′‐trimethyl‐1‐(4‐nitro‐phenyl)‐pyrazolin‐4‐spiro‐2′‐oxiran‐5‐one 3b undergoes rearrangement to the 1,3‐dioxolo[4,5‐c]pyrazole 12.
Cyclofunktionalisierung von 2‐Allyl‐phenolen mit Schwefelchloriden 2,3‐Dihydrobenzofurfurylthioether aus 2‐Allyl‐phenolen und aromatischen Sulfenylchloriden
Authors: Mühlstädt M. , Schubert Ch. , Kleinpeter E. 
Published: December 2004

Cyclofunctionalization of 2‐Allyl‐phenols with Sulfur Chlorides. Synthesis of 2,3‐Dihydrobenzofurfuryl Thioethers by the Reaction of 2‐Allyl‐phenols with Aromatic Sulfenyl ChloridesReactions of different substituted 2‐allyl‐phenols (2a–h) with either phenylsulfeny chloride (3) or 4‐methyl phenylsulfenyl chloride (4) yield the products of a cyclofunctionali zation 2‐phenylthiomethyl 2,3‐dihydrobenzofuranes (6a–h) or 2‐(4′‐methylphenyl) 2,3‐dihydrobenzofurane (7a–g), respectively. The identification of the products was carried out by mass spectroscopy and 1H‐n.m.r.‐spectroscopy. Isomeric compounds, i.e. 3‐phenylthio 2,3‐dihydrobenzopyranes (10) were not obtained. The reaction is Markovnilov‐directed. In the case of the treatment of 2‐allyl‐phenols with 2‐nitro phenylsulfenyl chloride (5) we have obtained mixtures of 2‐(2′‐nitrophenyl) thiomethyl 2,3‐dihydrobenzofuranes (8a–d) and of simple Markovnikov adducts, so‐called β‐chlorothioethers. The mixtures were identified by 1H‐n.m.r.‐ and mass spectroscopic (9a–d) methods.
Synthese von 1,2,4‐Benzotriazin‐3‐ylessigsäureestern und‐amiden
Authors: Wilde H. , Hauptmann S. , Kanitz A. , Franzheld M. , Mann G. 
Published: December 2004

Synthesis of 1,2,4‐Benzotriazine‐3‐acetates and ‐acetamidesSubstituted 1,2,4‐benzotriazine‐3‐acetates 6 are prepared by the reduction of (2‐nitrophenyl)hydrazonoethers 4 or (2‐nitrophenyl)amidrazones 5. The 1,2,4‐benzotriazin‐3‐ylacet‐anilid 9g forms a yellow azomethine dye 10 by oxidative coupling with N,N‐diethyl‐p‐phenylenediamine.
Solvenseffekte bei der Photoinduzierten Elektronenübertragung von ungeladenen Donatoren auf Arendiazoniumsalze
Authors: Becker H. G. O. , Israel G. 
Published: December 2004

Solvent Effects in the Photoinduced Electron Transfer Reaction of Uncharged Donors with Arenediazonium SaltsIn the photochemical electron transfer reactions to arene diazonium salts no strong Coulomb forces arise but the rate constants possibly vary in dependence on the state of the diazonium salt (tight ion pair in nonpolar solvents or free diazonium cations). This problem is studied in the present work using anthracene and tetracene, respectively, as electron donors. They react in their S1 states diffusion‐controlled with ion pairs ArN2⊖ BF4⊖, whereas the respective triplet reactions proceed up to 103 times more slowly. These rates are not significantly influenced by the dielectric properties of the solvent. Thus, ion pairing of the diazonium salts in solvents of low polarity has no screening effect on the electron transfer.This behavior is explained including electrostatic effects into the MARCUS theory of outer sphere electron transfer processes. No indication of a Marcus inverted region was found.
13C‐ und 1H‐NMR‐spektroskopische Untersuchungen an 2,9‐substituierten Fluorenen
Authors: Hauser A. , Thurner J.‐U. 
Published: December 2004

13C‐ and 1H‐NMR‐spectroscopical Investigations of 2,9‐substituted FluorenesThe 13C‐ and 1H‐chemical shifts for a series of 9‐substituted fluorenes and 9‐substituted 2‐nitrofluorenes, where the substituents are various azarenium ions, have been determined, shift data for several other fluorenyl compounds are also presented. The exact assignments of the 13C‐signals are possible by comparison of calculated shifts from 13C‐data with experimental 1H‐values. The substituent effects are discussed in terms of transmissions of electronic interactions. The substituent chemical shifts (SCS) for selective positions of the fluorene system give a linear correlation with the substituent constants σI, F, respectively. An increment model for the calculation of the empirical 13C‐chemical shifts of N‐(2‐nitrofluorene‐9‐yl)azareniumions 3b–6b are presented.
N‐Aminierung von Isochinolinbasen
Authors: Andreae Siegfried , Schmitz Ernst , Sonnenschein Helmut , Dörnyei Gábor , Szántay Csaba , Tamás Jozsef 
Published: December 2004

N‐Amination of Isoquinoline Bases3, 3‐Pentamethylene oxaziridine 1 forms an NN‐bond with secondary isoquinoline bases 2a–f to give the cyclohexylidene hydrazines 3a–f. In some cases nitrogen elimination yielding indane derivatives 13b, 13e competes with hydrazone formation. The cyclic Schiff'base 14 and the β‐carboline derivative 16 can also be aminated.
Pyryliumverbindungen. XXVII. Spezifisch deuterierte Carbo‐ und Heterocyclen via 2,4,6‐Triaryl‐[3,5‐2H2]pyryliumsalze
Authors: Fischer Gerhard W. , Möbius Günter 
Published: December 2004

Pyrylium Compounds. XXVIII. Specifically Deuterated Carbo‐ and heterocycles via 2,4,6‐Triaryl[3,5‐2H2]pyrylium SaltsOn heating with catalytic amounts of bases(e.g. triethyl amine) in deuterated alcohols such as methan[2H]ol or ethan[2H]ol pseudobases of 2, 4, 6‐triarylpyrylium salts 1 undergo fast1H/2H isotopic exchange reaction affording 1, 3, 5‐triaryl[2, 4, 4‐2H3]pent‐2‐ene‐1,5‐diones which with [2H] perchloric acid give highly deuterated 2, 4, 6‐triaryl‐[3, 5‐2H] pyrylium perchlorates 8. These salts are obtainable also directly from 1 through a one‐pot procedure by ring opening of the latter with deuterium oxide under the above‐mentioned1H/2H isotopic exchange conditions followed by recyclization of the formed 1, 3, 5‐triaryl[2, 4, 4‐2H3]pent‐2‐ene‐1, 5‐diones with [2H]ClO4. Ring transformations of 2, 4, 6‐triphenyl[3, 5‐2H2]pyrylium perchlorate (8a) to 2, 4, 6‐triphenyl[3, 5‐2H2]nitrobenzene (9) 2, 4, 6‐triphenyl[3, 5‐2H2]pyridine (10), 1, 2, 4, 6‐tetraphenyl[3, 5‐2H2]pyrydinium perchlorate(11), 2, 4, 6‐triphencyl[3, 5‐2H2]thiopyrylium perchlorate(12), 2‐benzoyl‐3, 5‐diphenyl[4‐2H]furan (13), and 3, 5, 7‐triphenyl‐[4, 4, 6‐2H3]4H‐1, 2‐diazepin (14) demonstrate the usability of pyrylium salts of type 8 as starting materials for syntheses of specifically deuterated carbo‐ and hetrocycles.
Massenspektrometrische Untersuchungen an 16,17‐Aminoalkoholen des 3‐Methoxy‐1,3,5(10)‐östratriens
Authors: Schade W. , Schönecker B. , Vokoun J. 
Published: December 2004

Mass Spectrometric Studies on 16, 17‐Amino Alcohols of 3‐Methoxy‐1,3,5(10)‐estratrieneThe electron impact ionization mass spectra of the four isomeric 16, 17‐amino alcohols of 3‐methoxy‐1, 3, 5(10)‐estratriene and their N‐acetyl and N, O‐diacetyl derivatives have been studied. The mass spectra of the isomeric amino alcohols are similar, whereas those of the isomeric N‐acetyl and N, O‐diacetyl derivatives show some differences depending on the configuration of the substituents in positions 16 and 17. Possibilities of mass spectrometric differentiation between the isomers are discussed.