bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reaktionen mit Cyclobutendionen. LIII [1]. Neue heterocyclische Systeme durch Umsetzung von 4‐[‐(z)‐Benzyliden]‐2,3‐diphenyl‐cyclobut‐2‐enon mit Diazomethan
Authors: Knorr Harald , Ried Walter , Knorr Ursula , Oremek Gerhard 
Published: December 2004

Reaction of Cyclobutendiones. LIII. New Heterocyclic Systems by Reaction of 4‐[‐(z)‐Benzylidenene]‐2,3‐diphenyl‐cyclobut‐2‐enone with DiazomethaneThe addition of diazomethane to stable 4‐alkylidene‐cyclobut‐2‐enones gives at the same time the 1:1 adducts 2, and under elimination of 1 mole nitrogene the 1:2 adducts 3 respectively the 1:3 adducts 4.
1,2,3‐Triazabutadiene. IX. 15N‐NMR‐spektroskopische Untersuchungen an cis‐trans‐isomeren 1‐Aryl‐3‐[3‐methylbenzthiazolinyliden‐(2)]‐triazenen und ‐triazeniumsalzen
Authors: Fanghänel E. , Radeglia R. , Hauptmann D. , Tyszkiewicz Brunhilde , Tyszkiewicz M. 
Published: December 2004

1,2,3‐Triazabutadienes. IX. 15N‐NMR‐spectroscopic Investigations of Cis‐Trans‐Isomeric 1‐Aryl‐3‐[3‐methylbenzthiazolinyliden‐(2)]‐triazenes and ‐triazenium‐saltsThe 15N‐chemical‐shifts and coupling constants of systematically 15N‐labeled cis‐trans‐isomeric 1,2,3‐triazabutadienes 1a–c and triazenium‐salts were determined and discussed with respect to the steric and electronic structure of the compounds. The chemical shifts correlate with the π‐electron density calculated in PPP‐approximation. The similarity of the chemical shifts and coupling constants of the respective alkylated and protonated compounds proves the preferred protonation of the trans triazabutadien chain in N1‐position.
Organische Phosphorverbindungen. XII [1]. Zum Hydrolyseverhalten von O,O‐Dimethyl‐O‐(1,2‐dibrom‐2,2‐dichlorethyl)‐phosphat (Naled)
Authors: Jentzsch Renate , Fischer Gerhard W. 
Published: December 2004

Organic Phosphorus Compounds. XII. The Hydrolytic Behaviour of O,O‐Dimethyl O‐(1,2‐Dibromo‐2,2‐dichloroethyl) Phosphate (Naled)The hydrolysis of Naled 2, an organophosphorus pesticide accessible by bromination of the enolphosphate Dichlorvos 1, in unbuffered aqueous solution does not only lead — as hitherto described — to dimethyl phosphate 3 and bromodichloroacetaldehyde 4 (path A), but also via intermediate formation of Desmethylnaled 5 to monomethyl phosphate 6 (path B). Kinetic measurements show that in the temperature range of 20–30°C both reactions proceed with similar velocities, and the primary step 2 → 5 determines the rate of path B. In comparison to Dichlorvos 1 the hydrolytic stability of Naled 2 has been found to be markedly lower. — The information on the degradation of Naled in unbuffered aqueous solution is completed by studies on the pH‐dependence of the hydrolysis and on the alkylation capacity of this pesticide.
Cyansäureester. 25 [1]. Umsetzung von Mercapto‐N‐heterocyclen mit Arylcyanaten
Authors: Martin Dieter , Wenzel Angelika , Bacaloglu Radu 
Published: December 2004

Cyanic Acid Esters. 25 The Reaction of Mercapto‐N‐heterocycles with Aryl CyanatesUnsaturated N‐heterocycles containing a cyclic thio urea structure and aryl cyanates (molar ratio 1:2), react to form azolo(1,2‐d) (1,2,4)thiadiazoles. This reaction has a wide scope concerning starting materials and gives good yields. Under the same conditions 2‐thione‐benzthiazolin is transformed to the corresponding disulfide. 4,5‐Bis‐mercaptomethylene‐o‐xylene and aryl cyanates give 2,3‐dithia‐6, 7‐dimethyl‐tetraline.
Oxidative Kupplung CH‐acider Verbindungen mit p‐Phenylendiaminen. II [1]. Reaktivität 4‐substituierter 1‐Hydroxy‐2‐naphthanilide gegenüber N,N‐Diethyl‐chinon‐(1,4)‐diimin
Authors: Mann G. , Wilde H. , Lehmann J. , Schindler W. 
Published: December 2004

Oxidative Coupling of CH‐acid Compounds with p‐Phenylene Diamines. II. Reactivity of 4‐Substituted 1‐Hydroxy‐phenyl‐2‐naphthalene‐carboxamides with N,N‐Diethyl‐quinone‐(1,4)‐diamineSubstitution products of 1‐hydroxy‐N‐3,5‐(dimethoxycarbonyl)‐phenyl‐2‐naphthalenecarboxamide 1–16 with halogene, ‐OR, ‐SR and ‐NRR′ substituents in position 4 were synthesized. A great part of these compounds react with N,N‐diethyl‐quinone‐(1,4)‐diimine by elimination of the substituent giving the same indophenol dye which is received by oxidative coupling of the unsubstituted compound. Evidence about the degree of side reactions is obtained by measurement of dye yields.
Desaktivierungsverhalten von Arenen und Heteroarenen. XI. Nachweis strahlungslos desaktivierender Excimere durch Resonanzenergietransfer
Authors: Bendig J. , Kreysig D. 
Published: December 2004

Deactivation Behaviour of Arenes and Heteroarenes. XI. The Evidence of Radiationless Deactivating Excimers by Resonance‐Energy TransferInvestigations of resonance‐energy transfer in the systems of anthracene‐/ and akridizinium ion/rhodamine B (BF4) show, that in the case of high concentrations of energy donors the amount of the relative fluorescence quantum yield is greater than one. This result demonstrates the existence of a further energy donor, the excimer. In the case of the N‐methyl‐acridinium ion/ rhodamine B (BF4)‐system this fact cannot be observed, therefore a formation of excimers at high concentrations should be excluded. The existence (anthracene, akridizinium ion) and non‐existence (N‐methylacridinium ion) of excimers is in agreement with the ability of forming photodimers.
Selektive Umsetzungen von Kohlenhydraten mit Isocyanaten
Authors: Zinner H. , Langer T. 
Published: December 2004

Selective Reactions of Carbohydrates with Isocyanates6‐O‐Arylcarbamoyl‐D‐galactose dialkyl dithloacetals 2a–n are prepared by selective reactions of D‐galactose dialkyl dithioacetals with aryl isocyanates in pyridine. Some of them are acetylated to give the 2,3,4,5‐tetra‐O‐acetyl derivatives 3a, b, i–m. The structures of the compounds 2 and 3 are proved by further synthesis from 1,2;3,4‐di‐O‐isopropylidene‐D‐galactose or 2,3,4,5‐tetra‐O‐acetyl‐D‐galactose diethyl dithioacetal, respectively.
Reaktionen von Bis‐enaminen mit Aldehyden — Neue Synthesen für 1,3‐Oxazine und Pyridine
Authors: Adler B. , Burtzlaff Ch. , Duschek Ch. , Ohl J. , Schmidt H. , Zech W. 
Published: December 2004

Reactions of Bis‐enamines with Aldehydes ‐ New Synthesis of 1,3‐Oxazines and PyridinesIn the presence of phosphoric acid N‐alkyl‐dipropenylamines react with aliphatic aldehydes to form substituted 1,3‐oxazines. With benzaldehyde this reaction does not proceed, but azomethines are formed. N,N‐dipropenylaniline with aldehydes also gives azomethines, a dihydropyridine is formed as well. From tripropenylamine and aldehydes substituted pyridines are obtained.
Action of Grignard Reagents on Mixed Biimides
Authors: Awad W. I. , Kandile N. G. , Ismail M. F. 
Published: December 2004

Reaktion von Grignardverbindungen mit gemischten DiimidenN‐Phthalimidosukzinimid 1 und N‐Phthalimidomaleinsäureimid 2 entstehen aus N‐Aminophthalimid und Succzinsäure‐ bzw. Maleinsäureanhydrid. 1 reagiert mit Grignardverbindungen zu den 3, 3‐disubstituierten Phthaliden 3 und N‐Aminosucczinimid. 2 reagiert mit Grignardverbindungen ebenfalls zu den Phthaliden 3 und einem schwer zu reinigenden Verbindungsgemisch. N‐Phthalimidomaleinsäureimid 2 reagiert leicht mit Diazoalkanen und Stickstoffwasserstoffsäure.
Analyse von technischem Diphenylolpropan (Dian) durch Schnelle Flüssigchromatographie
Authors: Eppert G. , Stief C. , Schinke I. 
Published: December 2004

Analysis of Technical Diphenylolpropane (Bisphenol A) by High‐performance Liquid ChromatographyA method for the investigation of technical 2,2‐bis‐(4′‐hydroxyphenyl)‐propane (bisphenol A) by high‐performance liquid chromatography is described. Microspherical silicagel in unmodified (adsorption) and C16‐modified form (reversed phase) was used as support. It has been found that supports with small particle sizes (5 μm) achieve their optimum efficiency only when they possess an adequately narrow optimum particle size distribution.The investigations were carried out using a self‐made apparatus. Details concerning an UV‐cell being insensitive to gas bubbles as well as a differential refractometer, which can be disassembled, are presented.
Untersuchungen zur Sulfochlorierung von Paraffinen. IV. Über die Sulfochlorierung von Isobutan
Authors: Kopinke F. D. , Kröckel W. , Pritzkow W. , Mateew K. , Radeglia R. 
Published: December 2004

Studies on Sulphochlorination of Paraffins. IV. On the Sulphochlorination of IsobutaneIn the sulphochlorination of isobutane at −20 to −10°C a mixture of 20–25% tert.‐butyl and 75–80% of isobutyl sulphochlorides is formed. The mixture has been analyzed by 1H‐ and by 13C‐n.m.r.‐spectroscopy. It is possible to transform the mixture of sulphochlorides into mixtures of the corresponding sulphonates, sulphonic acid methyl esters or sulphonic acid demithylamides. During the work‐up of the sulphochlorination mixtures it is necessary to keep the temperature low, because tertiary butyl sulphochloride is desulphonated at a noticeable rate already at temperatures above 35°C.
Quantenchemische Untersuchung der Cycloaddition von Phenol an Phenylcyanat als Beispiel für das Studium von MO‐Korrelationsdiagrammen im Falle der Abwesenheit von Symmetrieelementen im Übergangskomplex
Authors: Ritschl Friedrich 
Published: December 2004

Quantum Chemical Investigation of the Cycloaddition of Phenol to Phenylcyanate as an Example for the Study of M.O. Correlation Diagrams of Systems without Symmetry Elements in the Transition State.There is experimental evidence, that the N‐monomethylaniline‐catalyzed addition of phenol to phenylcyanate proceeds via a six‐membered, cyclic transition state, in which N‐mono‐methylaniline is involved, whose presence as a catalyst is necessary. In the present work is investigated by quantumchemical considerations, whether an analogy can be found between this reaction and a symmetry‐allowed [2 + 4]cycloaddition of π‐systems. Using the CNDO/2‐method an energy curve has been calculated, having only a small activation barrier. The wavefunctions at some points of the reaction coordinate have been localized to bond orbitals, which are then taken into some linear combinations. These do not show any change of their nodal behaviour at points belonging to the starting resp. to the final state of the reaction. This shows, that the above mentioned analogy is valid. For the [2 + 2]cycloaddition in absence of the catalyst, on the contrary, the energy curve shows a very high activation energy, and the nodal behaviour of the combined localized orbitals is changed on passing from the starting to the final state.
Synthese und Reaktionen von 2‐[Bis‐(alkylthio)‐methyliden]‐indan‐1,3‐dionen
Authors: Augustin M. , Groth Ch. , Kristen H. , Peseke K. , Wiechmann Ch. 
Published: December 2004

Synthesis and Reactions of 2‐[Bis‐(alkylthio)‐methyliden]‐indan‐1,3‐dionesThe 2‐[bis‐(alkylthio)‐methyliden]‐indan‐1,3‐diones 3 and especially the methyl‐compound 3a react with nucleophiles by substitution of the CH3Sgroup. The reaction with amines are yields the S,N or N,N‐acetales 7 and 8, respectively. Diamines, amino hydroxy‐ or amino‐mercapto compounds as dinucleophiles give the cyclic compounds 9 or the condensed heterocycles 12 and 16, where the carbonyl group has been integrated in the cyclisation. Also carbanions react with 3a under substitution. The structures of the final products are determined with ir‐, 1H‐n.m.r.‐ and ms‐spectra.
Tetrathiafulvalene. VII [1]. Arylenverbrückte polymere Tetrathiafulvalene
Authors: van Hinh Le , Schukat G. , Fanghänel E. 
Published: December 2004

Tetrathiafulvalenes. VII. Arylene‐bridged Polymeric TetrathiafulvalenesSynthesis and properties of phenylene — and biphenylbridged polymeric tetrathiafulvalenes, which are substituted by two methyl‐groups in the 3‐ and 6‐position, are described. These polymers react with bromine, iodine or tetracyanoquinodimethane to form the radical cation salts, whose electrical conducticity are estimated by means of powder compactions. The differences in the conductivity of the TCNQ‐salts and radical cation halides are very small. The phenylene‐bridged polymer‐salts show a higher conductivity than the bi‐phenylylene‐bridged ones up to values of 10−3Ω−1 cm−1. Surprisingly the monomer salts have a lower conductivity than the polymer salts.
Quantenchemische Untersuchungen zur Farbe und Stereodynamik von acyclischen Azinen. IIZum Einfluß tordierter S0‐Molekülgeometrien auf das Spektralverhalten und den Photochromie‐Effekt des Benz‐ und Anthraldazins
Authors: Gustav K. , Vettermann S. , Rose I. 
Published: December 2004

Quantum Chemical Study on Colour and Stereodynamics of Acyclic Azines. II. Influence of Twisted S0 Molecular Geometries on the Spectral Behaviour and the Photochromic Effect of Benz‐ and AnthraldazineOn the basis of quantum chemical calculations the influence of twisted molecular geometries on the spectral behaviour of (1E,3E)‐ and (1E,3Z)‐isomers of benz‐ and anthraldazine has been investigated. It is possible to point out structural peculiarities in the S0 state and to explain the photochromic effect of the arylsubstituted acyclic azines.
Propellanes. I. 3,6,10,13‐Tetrathia(4,5,11,12‐trans‐dicyclohexano)‐(6,6,1)propellane
Authors: Jamrozik Janusz 
Published: December 2004

Propellane. I. 3,6,10,13‐Tetrathia(4,5,11,12‐trans‐dicyclohexano)‐(6,6,1)propellanDurch Reaktion des 1,1,2,2‐Tetrabrommethylcyclopropans mit trans‐1,2‐Dimercaptocyclohexan wurde die tricyclische Verbindung 1 mit Propellan‐Struktur erhalten. Die Struktur dieser Verbindung wurde mit Hilfe spektroskopischer Daten und der Fragmentierung der Massenspektren ermittelt. Für die beiden achtgliedrigen Ringe wird eine “twist‐crown” Konformation vorgeschlagen. Die Oxidation des (6,6,1)Propellans 1 führt zu dem entsprechenden Tetrasulfon, in dem der Cyclopropan‐Ring erhalten bleibt.
Katodische Reduktion von Keten‐S,S‐acetalen
Authors: Rüttinger H.‐H. , Rudorf W.‐D. , Matschiner H. 
Published: December 2004

Cathodic Reduction of Ketene S,S‐acetalsKetene S,S‐acetals are reduced in protic media by the cleavage of one S‐alkyl group. The resulting carbanion either may be protonated or reacts with the starting material to yield dimers. The effects of different substituents on the half‐wave potentials and the rate constants of amination have been investigated.
MO‐LCAO‐Berechnungen an Polymethinen. XI Lokale spektrale Anregungen in polynuclearen Cyaninfarbstoffen
Authors: Fabian J. , Zimmer A. 
Published: December 2004

MO‐LCAO Calculations on Polymethines. XI. Local Spectral Excitations in Polynuclear Cyanine DyesVarious branched‐conjugated cyanine dyes display long‐wavelength absorption bands similar in position to those of their straight‐chain substructures. According to the analysis of results of PPP‐type calculations this close similarity results from a partial localization of the electronic transitions, whereas the participating electronic states are highly delocalized. The long‐wavelength absorptions of symmetrically‐branched trinuclear cyanine dyes have an entire molecular chromophore origin resulting from twofold degenerate electronic transitions. Lowering of the symmetry brings about a splitting of the colour‐band.In contrast to the branched‐conjugated cyanine dyes various tetranuclear cyanine dyes can be considered as being composed of two subchromophores either directly linked or joined through a conjugative bridge. In accordance with PPP configuration analyses and LHM‐type calculations the splitting of the colour band is best understood by composite‐molecule approaches. In this context the applicability of the simple molecular exciton theory is discussed.
Zur Rolle von EDA‐Komplexen bei kationischen Polymerisationen. VI[1]. Wechselwirkung von Halogenidionen mit organischen aπ‐Elektronenacceptoren
Authors: Heublein GÜNther , Spange Stefan , Hallpap Peter 
Published: December 2004

The Role of Donor‐Acceptor Complexes in Cationic Polymerisations. The Interaction of Halide Ions with Organic aπ‐AcceptorsThe anions of salts of the type Kat+X− (Kat+  Li+, Na+, Et4N+; X−  Cl−, Br−, I−) form donor‐acceptor complexes with organic a π‐acceptors. The long‐wave charge‐transfer absorption show a bathochrome shift with higher periodic numbers of X− and increasing electron affinity of the acceptors Acc. Strong acceptors form radical ions very rapidly with X  I and slowly with X  Br. Cl.The interactions in the system Kat+X− → Acc are influenced by solvents in a very complex way. As acceptors they interact preferably with the halide ion X− and, hence, reduce its donicity for the competing acceptor Acc. As donors they change the dissociation of the ion pair Kat+X− by solvation of the cation Kat+ and influence in that indirect way also the donicity of X− for the acceptor Acc.
Isostere Adsorptionswärme des Ethans an Zeolithen vom Typ NaX und NaY
Authors: Stach H. , Throl U. , Schirmer W. 
Published: December 2004

Isosteric Heat of Adsorption of n‐Ethane on Zeolites NaX and NaYUsing a volumetric method isotherms of adsorption of ethane on zeolites NaX and NaY were measured. The Clausius‐Clapeyron equation was used to calculate the isosteric heat of adsorption of the paraffin on both molecular‐sieves. These enthalpies show a linear dependence of the amount of adsorbed molecules. The zeolite with the higher charge density shows a larger heat of adsorption. The difference in the heat of adsorption is explained by adsorption on different centers in the cavity of both zeolites.
Ionenpaareffekte bei der Photolyse und Thermolyse von Aryldiazonium‐tetrafluoroboraten
Authors: Becker H. G. O. , Israel G. 
Published: December 2004

Ion Pair‐Effects in the Photolysis and Thermolysis of Arenediazonium TetrafluoroboratesFluoroarenes produced by Schiemann‐reaction of p‐methyl‐ and p‐tert.‐butyl‐benzenediazonium tetrafluoroborates in solution are formed mainly from ArN2+/BF4−‐ion pairs. The ratio of product yields formed from the reaction of arene cations with the solvent to the yields of fluoroarenes increases with increasing KD/α; KD is the conductometrically determined dissociation constant, and α the dissociation degree of ion pairs. The photochemical and thermal dediazoniation gives the same product ratios, indicating, that both sorts of reactions proceed via the same intermediate — the arene cation.
Synthese eines Insulin‐A‐Kettenfragmentes A14–21 mit der Diphenylmethyl‐Schutzgruppe am Cystein
Authors: Kaufmann K.‐D. , Schönherr C. H. , Jeschke C. , Bauschke S. , Kietzer M. , Dölling R. 
Published: December 2004

Synthesis of an Insulin A‐Chain Fragment A14–21 with the Diphenylmethyl Protecting Group for CysteineThe synthesis of the C‐terminal octapeptide of the insulin A‐chain, N‐2‐[biphenylyl‐(4)]‐propyl‐(2)‐oxycarbonyl‐O‐tert.‐butyl‐L‐tyrosyl‐L‐glutaminyl‐L‐leucyl‐γ‐tert.‐butyl‐L‐glutamyl‐L‐asparaginyl‐O‐tert.‐butyl‐L‐tyrosyl‐S‐diphenylmethyl‐L‐cysteinyl‐L‐asparagine‐tert.‐butylester, by conventional fragment condensations is described.
Tieftemperaturuntersuchungen zur Photochromie von Triphenylformazan
Authors: Langbein H. 
Published: December 2004

Low‐Temperature Investigations of Photochromic Triphenylformazan.Absorption spectra and photochromic behaviour of triphenylformazan‐isomers at low temperature have been investigated. It is shown, that the scheme of Kuhn and Weitz [13] is somewhat unsatisfying: Photoisomerization of triphenylformazan occurs only about the NN‐double bond, isomerization about the CN‐double bond is a thermal reaction. The absorption spectra of the two intermediates between the stable red form and the metastable yellow form have been calculated by the method of Fischer.At low temperature the quantum yield of trans‐cis‐photoisomerization about the NN‐link of triphenylformazan becomes smaller. The cis‐trans‐isomerization is insensitive to changes in temperature.
Allgemeine Synthesen und rationelle Strukturparameter isomerer Derivate von [3,4]‐kondensierten Pyrazolen
Authors: Dorn Helmut , Ozegowski Rüdiger 
Published: December 2004

General Syntheses and Rational Parameters for Structural Assignment of Isomeric Derivatives of [3,4]‐fused Pyrazoles4 isomeric 1‐ or 2‐methyl‐, and 1‐ or 2‐benzyl‐pyrazolo[3,4‐b]pyridones, i.e. the 4‐oxo‐types17a, bor11a, band the 6‐oxo‐types16a, bor10a, b, are synthesized unambiguously. Cyclisation of 1‐substituted 3‐ or 5‐(1‐methyl‐2‐ethoxycarbonyl‐vinylamino)‐pyrazoles9a, bor.15a, b, which were synthesized from 1‐substituted 3‐ or 5‐amino‐pyrazoles and ethyl acetoacetate yields11a, bor17a, bin downtherm, but10a, bor16a, bin presence of acidic catalysts. The acidic cyclisation is preceded by a new rearrangement of9or15into 1‐ substituted 3‐27or 5‐amino‐4‐(1‐methyl‐2‐ethoxycarbonyl‐vinyl)‐pyrazoles30; mechanism and concurring reactions are explained. Because of their higher electron densities at C‐4 it is easier to cyclise derivatives of 5‐amino‐pyrazoles compared to 3‐amino‐pyrazoles. All isomeric 1‐ or 2‐substituted 4(6)‐chloro‐6(4)‐methyl‐pyrazolo‐[3,4‐b]pyridines are formed with POCl3from the corresponding oxo‐compounds.The position of a substituent at N‐1 or N‐2 of [3,4]‐fused pyrazoles can be assigned using the significant1H‐n.m.r.‐parameter Δ= δ— − δHMPT(conc. HC—3). If solvent influences are considered, δ(C  O) is a useful13C‐n.m.r.‐parameter to distinguish the 4‐oxo‐types (11a, b; 17a, b) from the 6‐oxo‐types (10a, b; 16a, b) of pyrazolo[3,4‐b]pyridones. Further own and lit. dates conc. structural assignment (n.m.r., i.r., u.v.) are discussed critically.
Substituenteneffekte in den 13C–NMR‐Spektren von diastereomeren Chalkon‐dihalogeniden. I. Untersuchungen an diastereomeren Chalkondibromiden und Chalkonbromchloridaddukten
Authors: Weber Fritz Gerd , Radeglia Reiner 
Published: December 2004

Substituent Effects in 13C‐N.M.R. Spectra of Diasteroemeric Chalcone Dihalogenides. I. Investigations of Diastereomeric Chalcone Dibromides and Bromochlorides AdductsFourier‐transform 13C‐n.m.r. spectra of two series of chalcone dihalogenides 1 und 2 including some pairs of diastereomeres are reported. All of the carbon resonances are assigned. Substituent effects on the chemical shifts of carbonyl‐, α‐ and β‐C‐atoms in dependence on the position of the substituent in ring A or B in both of systems are discussed. The dependence of chemical shifts on the erythro or threo configuration is studied.
Condensation of Aryl Benzyl Ketones with Dimethyl Diglycollate
Authors: El‐Newaihy M. F. , Salem M. R. , Enayat E. I. , Abdel‐Hamid H. A. , El‐Bassiouny F. A. 
Published: December 2004

Kondensation von Arylbenzylketonen mit DimethyldiglycollatPhenyl‐, p‐Tolyl‐ und p‐Chlorphenyl‐benzylketone kondensieren mit Dimethyldiglycollat in Gegenwart von Natriumhydrid in guten Ausbeuten zu den entsprechenden Z‐Halbestern 2a–e. Struktur und Konfiguration der Halbester wurde durch chemische und spektroskopische Befunde gestützt.
Theoretische Untersuchungen zum elektrophilen Angriff. VIII. Das protonierte Pyrrol
Authors: Illek B. , Grimmer M. , Heidrich D. 
Published: December 2004

Theoretical Studies to the Electrophilic Attack. VIII. The Protonated PyrroleThe potential surface of protonated pyrrole was analysed for minima and saddle points of first and higher order by special numerical methods. The calculations were carried out on the basis of semiempirical methods tested in the past on related cationic systems.The relative energies of face protonated pyrrole, the σ‐complexes and H‐bridged structures were compared with recent results on the benzene‐H+ system to interprete the H‐shifts in the cation and the intermediates in the proton exchange reaction. Theoretical suggestions for solvatation effects are considered in the discussion. One of the most striking results is the high barrier for the H‐shift from the N‐protonated form to the α‐position.
Spektroskopische und Dipolmoment‐Untersuchungen an Halogenfluorid‐Additionsprodukten der Chalkone
Authors: Weber Fritz Gerd , Giese Hartmut , Köppel Hubert 
Published: December 2004

Spectroscopical and Dipole Moment Investigations of Halogen Fluoride Addition Products of ChalconesChalcone halogen fluoride addition products 1–3 are investigated in the i.r. and 1H‐n.m.r. spectroscopy field as well as in the substituent dependence of spectral parameters and molecular dipole moment. The assign of configuration and conformation on basis of 1H‐n.m.r. spectroscopy and dipole moments are discussed.