bluuebunny/crossref_metadata_2025_split huggingface dataset:
Arbeiten über Phosphorsäure‐ und Thiophosphorsäure ester mit einem heterocyclischen Substituenten. 2. Mitteilung. Eine verbesserte Methode zur Herstellung von 1, 3, 4‐Oxadiazol‐2(3H) onen und von Thio‐ und Dithiophosphorsäure‐O, O‐dialkyl‐S‐[(1, 3, 4‐oxadiazol‐2(3H)‐on‐3‐yl)‐methyl]‐estern
Authors: Rüfenacht K. 
Published: December 2004

AbstractSome 1,3,4‐oxadiazol‐2(2H)‐ones with aliphatic substituents in 5‐position are prepared in good yields and converted via the 3‐hydroxymethyl derivatives to the corresponding 3‐chloromethyl derivatives which are suitable starting materials for the preparation of insecticidal O,O‐dialkyl‐S‐[(5‐subst.‐1,3,4‐oxidiazol‐2(3H)‐one‐3‐yl)‐methyl]‐thiophosphates and dithiophosphates.
Stoffwechselprodukte von Mikroorganismen. 108. Mitteilung. Kristallstrukturanalyse des Chlorothricolid‐methylesters
Authors: Brufani M. , Cerrini S. , Fedeli W. , Mazza F. , Muntwyler R. 
Published: December 2004

AbstractThe X‐ray crystal structure analysis of the Caesium salt of Chlorothricolide methylester, derived from the aglycone of the antibiotic chlorothricin, is described.
3α‐ und 3β‐Amino‐3‐desoxy‐digitoxigenin. Partialsynthetische Versuche in der Reihe der Herzgifte, 5. Mitt.
Authors: Sawlewicz Ludwika , Weiss Ekkehard , Linde Horst H. A. , Meyer Kuno 
Published: December 2004

AbstractZusammenfassung. Es wird die Synthese der im Titel genannten 3‐Amino‐cardenolide beschrieben.
Über atropisomere Biphenyl‐Derivate mit einer Pseudoasymmetrieachse
Authors: Helmchen G. , Prelog V. 
Published: December 2004

AbstractDiastereomeric biphenyl derivatives VIIIa and b have been prepared as first examples of compounds with an axis of pseudoasymmetry. Compound VIIIa was prepared by an unambiguous synthesis from (+)‐V. The absolute configuration of the latter was determined by correlation with (+)‐(R)‐2‐amino‐2′,6‐dimethyl‐6′‐nitro‐biphenyl (XII) and hence the configuration of VIIIa (and therefore also of VIII b) was established.
Application de la réduction polarographique des sulfones aromatiques et des p‐toluènesulfonates d'alkyle à des problèmes de structure
Authors: Gerdil Raymond 
Published: December 2004

AbstractThe polarographic reduction potentials of a series of aromatic sulfones and homologous alkyl tosylates in anhydrous NN‐dimethylformamide have been measured. The relation between reduction potential and structure is discussed on the basis of HMO. calculations, under the assumption that compounds PhSO2X (X = NR1R2, OR, halogens) are sulfone derivatives A critical approach is made of the use of the Taft‐Hammett relation for correlating half‐wave potentials. The different reduction mechanisms at the electrode observed in aprotic and protic media for the above compounds are satisfactorily accounted for by simple MO. calculations.
Synthese von Haschisch‐Inhaltsstoffen. 5. Mitteilung
Authors: Petrzilka T. , Lusuardi W. G. 
Published: December 2004

AbstractA (−)‐Δ8‐6a,10a‐trans‐tetrahydrocannabinol analogue, with a methyl‐(3‐dimethyl‐amino‐propyl)‐amino side‐chain instead of the n‐pentyl radical in the naturally occurring product, has been synthesized by condensing 5‐methylamino‐resorcinol tosylate with (+)‐trans‐p‐2,8‐menthadien‐1‐ol.
Isolierung und Aminosäuresequenz von Substanz P aus Pferdedarm
Authors: Studer Rolf Otto , Trzeciak Arnold , Lergier William 
Published: December 2004

AbstractThe isolation and amino acid sequence of substance P from horse intestine is reported. The sequence, H‐Arg‐Pro‐Lys‐Pro‐Gln‐Gln‐Phe‐Phe‐Gly‐Leu‐Met‐NH2 is identical with the sequence reported for substance P isolated from bovine hypothalami.
Die Cyclopropylcarbinyl‐Cyclobutyl‐Homoallyl‐Umlagerung. I. Teil. Synthese von Tricyclo[3.2.1.02,7]octan‐3‐ol, endo‐ und exo‐Tricyclo[3.2.1.03,6]octan‐4‐ol und exo‐Bicyclo[3.2.1]‐oct‐2‐en‐7‐ol
Authors: Geisel Manfred , Grob Cyril A. , Santi Werner , Tschudi Werner 
Published: December 2004

AbstractTricyclo[3.2.1.02,7]octan‐3‐ol (1) and its 4‐isomer 7 were obtained by hydroboration of tricyclo[3.2.1.02,7]oct‐3‐ene (5). The former alcohol 1 is quantitatively converted to the isomeric alcohol exo‐bicyclo[3.2.1]oct‐2‐en‐7‐ol (3) by treatment with aqueous acid.Photolysis of 1‐diazo‐3‐(cyclopent‐3‐enyl)‐propan‐2‐one (12c) gave a high yield of tricyclo[3.2.1.03,6]octan‐4‐one (10a). Reduction of the latter ketone produced a mixture of endo‐ and exo‐tricyclo[3.2.1.03,6]octan‐4‐ol 2 and 9, respectively. Oxidation of these secondary alcohols with silver carbonate in benzene furnished a mixture of the ketone 10a and the lactone 14 of 6‐hydroxy‐bicyclo[2.1.1]heptane‐2‐carboxylic acid. The latter is thought to be formed by oxydation of the hydrate of the strained ketone 10a.
Etude des mécanismes de réarrangement dans la fragmentation des benzoyloxy‐cyclopentànes par impact électronique
Authors: Singy Gérard A. , Buchs Armand 
Published: December 2004

AbstractThe fragmentation modes of 3‐benzoyloxy‐cyclopentene and of 4‐benzoyloxy‐cyclopentene have been studied on deuterium‐labelled analogues. A mathematical model is proposed for the study of the rearrangement reactions which occur during the expulsion of H2O and of \documentclass{article}\pagestyle{empty}\begin{document}$ {\rm CO}_2 {\rm H}^. $\end{document} from the molecular ion of 3‐benzoyloxy‐cyclopentene.
Elektronenspinresonanz freier Radikale bei photochemischen Reaktionen von Ketonen in Lösung
Authors: Paul H. , Fischer H. 
Published: December 2004

AbstractTransient alkyl and acyl radicals are detected and identified by electron spin resonance during UV.‐Irradiation of dialkyl and alkyl aryl ketones in liquid solutions. They are formed by the primary processes of α‐cleavage, intermolecular photoreduction or α‐chloro elimination. For several ketones a temperature dependent competition between α‐cleavage and photo‐reduction is observed indicating a higher energy of activation for the cleavage than for the reduction process. The results are discussed with respect to the photochemical behaviour of the ketones.Electron spin resonance parameters are reported for a variety of radicals. In particular 13C coupling constants support a sigma type structure of acyl radicals and require a nearly planar radical center of t‐butyl and isopropyl radicals.
Addition of Xanthenyl and Thioxanthenyl Halides to Asymmetric Diarylethylenes and Their 2‐Halogeno‐Derivatives
Authors: Tadros Wadie , Sakla Alfy Badie , Awad Sami Bassili , Abdul‐Malik Nadia Fouad 
Published: December 2004

AbstractXanthenyl and thioxanthenyl halides added readily to asymmetric diarylethylenes and their 2‐halogeno‐derivatives to give after dehydrohalogenation 1,1‐diaryl‐2‐[xanthen(orthioxanthen)‐9‐yl]‐ethylenes and 1,1‐diaryl‐2‐halogeno‐2‐[xanthen(or thioxanthen)‐9‐yl]‐ethylenes. The thioxanthenylethylenes were also obtained by another way.Reactions of these ethylenes with bromine, chlorine or sulfuryl chloride were influenced by the halogen and the nature of the p‐substituent.Dehydrohalogenation of the 2‐halogenoxanthenyl(or thioxanthenyl) ethylenes gave the corresponding 1,1‐diaryl‐2‐[xanthen(or thioxanthen)‐9‐ylidene]‐ethylenes.
Conformational Study by ESR. of Some Alkyl Substituted 6a‐Thiathiophthene Radical Anions
Authors: Gerson Fabian , Heinzer Josef , Stavaux Madeleine 
Published: December 2004

AbstractESR. data are reported for the radical anions (II⊖ to VI⊖) of five alkyl substituted 6a‐thiathiophthenes. Rates and activation parameters for the inversion of the 3,4‐trimethylene chain in IV⊖, V⊖ and VI⊖ have been obtained by means of an iterative least squares computer program ESRCEX. Preferential conformations of the alkyl substituents are discussed in terms of the 〈cos2θ〉 dependence of the β‐proton coupling constants and with the aid of molecular models. Experimental evidence strongly suggests that the partial rotation of the ethyl and isopropyl groups in V⊖ and VI⊖ is correlated with the inversion of the 3,4‐trimethylene chain.
Eine neue Synthese des 3‐[3,4‐Dihydroxy‐phenyl]‐L‐alanins (L‐DOPA) aus L‐Tyrosin
Authors: Bretschneider Hermann , Hohenlohe‐Oehringen Kraft , Kaiser Ado , Wölcke Uwe 
Published: December 2004

AbstractL‐Tyrosin wird mit Acetylchlorid in Gegenwart von Aluminiumchlorid in 3‐Acetyl‐L‐tyrosin übergeführt, das mit Wasserstoffperoxid in alkalischem Milieu zu L‐DOPA oxydiert wird.
Aromatische [1,5s]‐sigmatropische H‐Verschiebungen in Arylallenen
Authors: Heimgartner Heinz , Zsindely Janos , Hansen Hans‐Jürgen , Schmid Hans 
Published: December 2004

Abstract1‐Mesityl allene (1), 1‐mesityl‐3‐methyl allene (2) and 1‐mesityl‐3,3‐dimethyl allene (3) rearrange thermally at 150–190° in decane via [1,5s]sigmatropic H‐shifts to yield the o‐quinodimethanes 4, which cyclise to give the 1,2‐dihydronaphthalenes 5 and 6 and/or undergo [1,7 a]sigmatropic H‐shifts to give 1‐mesityl‐(Z)‐buta‐1, 3‐dienes (Z)‐7 and (Z)‐8, respectively (Schemes 1,3,4 and 5) in almost quantitative yields. The activation parameters of these isomerisations are given in Table 1. 1‐Mesityl‐1‐methyl allene (9) isomerises at 190° to give 4,5,7‐trimethyl‐1,2‐dihydronaphthalene (17) in 50% yield (Scheme 6).2′‐Isopropylphenyl allene (10) in decane rearranges at 170° to 1‐(Z)‐propenyl‐2‐isopropenyl‐benzene ((Z)‐19, Scheme 7). Deuterium labelling experiments show that the rate determining step is an aromatic [1,5s]sigmatropic hydrogen shift from an sp3‐ to an sp‐hybridised carbon atom. The primary kinetic isotopic effect (kH/kD) is 3.45, while the secondary βisotopic effect is 1.20 (Scheme 7 and Table 2).
α‐Chlor‐nitrone IV: Zur Stereochemie der λ‐Lacton‐Synthese und eine Methode zum Aufbau von α‐Methyliden‐λ‐lactonen aus Olefinen. Über synthetische Methoden, 8. (vorläufige) Mitteilung
Authors: Petrzilka Martin , Felix Dorothee , Eschenmoser Albert 
Published: December 2004

AbstractThe Ag+‐induced reaction between N‐cyclohexyl‐α‐chloro‐propionaldonitrone and the two diastereomeric 2‐butenes in liquid SO2 is a stereospecific cis‐addition. The use of N‐cyclo‐hexyl‐α,β‐dichloro‐propionaldonitrone in this type of reaction provides a preparative route from olefines to α‐methylidene‐butyrolactones.
[4+2]‐Cycloadditionen von 1,2‐Dicyanocyclobuten und seine thermische Ringöffnung zum 2,3‐Dicyanobutadien‐1,3
Authors: Belluš Daniel , Bredow Klaus Von , Sauter Hanspeter , Weis Claus D. 
Published: December 2004

AbstractFacile synthetic routes to 1,2‐dicyanocyclobutene (3), cyclobutene‐1,2‐dicarboxylic acid (56) and derivatives thereof are presented, starting from 1,2‐dicyanocyclobutane (1), a commercially available acrylonitrile cyclodimer.The favored mode of [4+2]‐cycloadditions of 3 to cyclic dienes with sp3carbon atoms is the endo‐addition (above 90% relative yields of adducts with endo‐cyclobutane ring). Exo‐cycloaddition, however, is preferred by dienes having no sp3‐carbon atom (e.g. furane). Cyclisation reactions involving cis‐vicinal substituents in [4+ 2]‐cycloadducts afford (m.n. 2)‐azapropellanes 18, 74 and 77. 1H‐ and 13C‐NMR. spectra of the stereoisomeric adducts are discussed in detail. The structures of the furane adducts 14 and 15 were determined by 1H‐NMR. using the shift reagent Eu(dpm)3.Reactive butadienes 32, 53‐55 are obtained in high yield and purity by gasphase thermolysis (380–420°) of the correspondingly substituted cyclobutenes. 2,3‐Dicyanobutadiene‐l, 3 (32) gives good yields of [4 + 2]‐cycloadducts with strained cycloolefines, moderate yields with vinylethers and non‐activated olefins, and no adducts at all with electrophilic dienophiles (8.g. maleic anhydride, fumaronitrile). Thus, reactions of 32 are typical Diels‐Alder reactions with ‘inverse electron demand’.Some of these primary [4+2]‐cycloadducts (38, 39 and 45) were dehydrogenated to new aromatic ortho‐dinitriles 46‐48.
Synthesis of 2,5‐Diphenylbenzocyclopropene and 7,7‐Dideuteriobenzocyclopropene
Authors: Müller Paul 
Published: December 2004

AbstractDie Reduktion von 7,7‐Dichloro‐2,5‐diphenylbenzocyclopropen1 (1) mit Aluminiumhydrid liefert in 50% Ausbeute 2,5‐Diphenylbenzocyclopropen (2). Aluminiumdeuterid wandelt 7,7‐Difluorobenzocyclopropen (3) in 7,7‐Dideuteriobenzocyclopropen um.
Synthèses dans la série des bis‐indéno‐fluorènes, IX. Le dihydro‐13,15‐7H‐bis‐indéno[2.1‐b; 2′.1′‐h]fluorène et son dérivé méthylé en position 6
Authors: Chardonnens Louis , Barras Jean‐Luc 
Published: December 2004

AbstractBy condensation according Ullmann of 2‐iodo‐9‐oxo‐fluorene with 3‐bromo‐2‐cyano‐9‐oxo‐fluorene, followed by cyclisation and reduction, the new linear 13,15‐dihydro‐7H‐diindeno[2.1‐b; 2′.1′‐h]fluorene (III) is synthesized in 3 steps. The 6‐methyl‐derivative of II is also obtained in a similar way.
Beckmann Fragmentation and Rearrangement. Part VII. Fragmentation and cyclization of α‐methylthio‐ketoximes. Fragmentation reactions no. 27
Authors: Grob Cyril A. , Ide Junya 
Published: December 2004

Abstractα‐Methylthio‐propiophenone anti‐oxime p‐toluenesulfonate (tosylate) (12b) fragments quantitatively in 80% ethanol yielding benzonitrile and a methylidenesulfonium ion 15. The syn‐isomer, however, undergoes a Beckmann rearrangement. The fragmentation of α‐methylthio‐isobutyropher one anti‐oxime tosylate (13b) is accompanied by cyclization to the 1, 2‐thiazetin‐1‐ium ion 27, which is hydrolyzed via the sulfimine 29 to the keto sulfide 20 and the keto sulfoxide 30. A comparison of the rates of the α‐alkylthio anti‐ketoxime tosylates 12b and 13b and of the homomorphous oxime tosylates 16b and 17b shows that fragmentation and cyclization are strongly assisted by the sulfur atom. Whereas both the anti‐ and syn‐isomers of α‐amino ketoxime derivatives fragment quantitatively, only the anti‐isomers of α‐alkylthio ketoxime derivatives undergo facile fragmentation.
A Chemical Study of Burley Tobacco Flavour (Nicotiana tabacumL.) V. Identification and Synthesis of the Novel Terpenoid Alkaloids 1, 3, 6, 6‐Tetramethyl‐5, 6, 7, 8‐tetrahydro‐isoquinolin‐8‐one and 3, 6, 6‐Trimethyl‐5,6‐dihydro‐7H‐2‐pyrindin‐7‐one
Authors: Demole Edouard , Demole Cécile 
Published: December 2004

AbstractGLC. allowed the isolation of 1, 3, 6, 6‐tetramethyl‐5, 6, 7, 8‐tetrahydro‐isoquinolin‐8‐one (A) and 3,6,6‐trimethyl‐5,6‐dihydro‐7H‐2‐pyrindin‐7‐one (D) from Burley tobacco condensate (about 0.1% each). The structures and syntheses of these novel terpenoid alkaloids are described, and a possible way for their formation in tobacco is suggested.
Säurekatalysierte Umlagerung von 4‐Allyl‐cyclohex‐2‐en‐1‐olen; Beispiele für ladungskontrollierte [3s, 4s]‐Umlagerungen von cyclischen Allylkationen
Authors: Vittorelli Piero , Peter‐Katalinić Jasna , Mukherjee‐Müller Gabriele , Hansen Hans‐Jürgen , Schmid Hans 
Published: December 2004

AbstractThe acid‐catalysed rearrangement of the cyclohex‐2‐en‐1‐ols 15, d3‐15, 16, 17 and 19, the cyclohexa‐2,5‐dien‐1‐ols 20 and 21, and also the allyl alcohols 22 and 23 (Scheme 3), using 98‐percent sulfuric acid/acetic anhydride 1:99 at room temperature, was investigated. From the rearrangement of 4‐allyl‐4‐phenyl‐cyclohex‐2‐en‐1‐ol (15), with reaction times greater than 2 hours a single product is obtained, 4‐allyl‐biphenyl (50) in 33% yield (Scheme 9). With reaction times below 2 hours the acetate 53 from 15 was isolated, and this could be converted into 50. The reaction of 2′,3′,3′‐d3‐15 in Ac2O/H2SO4 lead to 1′,1′,2′‐d3‐50 (Scheme 11). The rearrangement of 4‐allyl‐4‐methyl‐cyclohex‐2‐en‐1‐ol (16) (Scheme 14) yielded 39% of the corresponding acetate 60 and 30% of 4‐allyl‐toluene (6), which also resulted by a rearrangement of 60 under the reaction conditions. These rearrangements are all [3s,4s]‐sigmatropic reactions, which proceed via the cyclohexenyl cation a (Scheme 12, R = C6H5, CH3). In Ac2O/H2SO4 the allyl‐cyclohexadienes primarely formed subsequently undergo dehydrogenation to yield the benzene derivatives 6, 50 and d3‐50.From the rearrangement of 4,4‐diphenyl‐cyclohex‐2‐en‐1‐ol (19) at 0° a reaction mixture is obtained which consists of the acetate 55, 2,3‐diphenyl‐cyclohexa‐1,4‐diene (57) and o‐terphenyl (56) (Scheme 10). Both 55 and 57 are converted under the reaction conditions to o‐terphenyl (56). No 4‐(1′‐methylallyl)‐biphenyl is obtained from the rearrangement of 4‐crotyl‐4‐phenyl‐cyclohex‐2‐en‐1‐ol (17). In this case, apart from the corresponding acetate 64, a single product 5‐(1′‐acetoxyethyl)‐1‐phenyl‐bicyclo[2.2.2]oct‐2‐ene (65) (Scheme 16) was obtained; under the reaction conditions the acetate 64 rearranges to 65.The rearrangement of 4‐allyl‐4‐phenyl‐cyclohexa‐2,5‐dien‐1‐ol (20) gives, as expected, not only 4‐allyl‐biphenyl (50) but also 2‐ and 3‐allyl‐biphenyl (51 and 52) and biphenyl (Scheme 13). 4‐Benzyl‐4‐methyl‐cyclohexa‐2,5‐dien‐1‐ol (syn‐ and anti‐21) gave in Ac2O/H2SO4 at 10° as rearrangement products 93% of 2‐benzyltoluene (97) and 7% of 4‐benzyl‐toluene (98) (Scheme 21). Hence [1,4]‐rearrangements in cyclohexadienyl cations, seems to occur only to a limited extent.The alicyclic alcohols 22 and 23 (Scheme 18) gave, in Ac2O/H2SO4, as main product the corresponding acetates 73 and 75, as well as small amounts of olefins 74 and 76 formed by dehydration i.e. [3,4]‐rearrangements occur in these systems. Also no [3,4]‐rearrangements were observed in solvents reactions of either 4,4‐dimethyl‐hepta‐1, 6‐dien‐3‐yl tosulate (79; see Scheme 19) or its corresponding alcohol 24.
Photoaffinitätsmarkierung von Chymotrypsin. Synthese der photolysierbaren Liganden
Authors: Escher Emanuel , Schwyzer Robert 
Published: December 2004

AbstractThe syntheses of m‐azido‐L‐phenylalanine, p‐azido‐o‐nitro‐L‐phenylalanine, Z · Ala‐Ala‐Xxx · OH, and Z · Ala‐Ala(β‐3H)‐Xxx · OH, with Xxx – Phe, Phe(p‐NO2), Phe(p‐N3), Phe(m‐N3), and Phe(p‐N3, o‐NO2) are described. The tripeptides with substituted phenylalanine residues are reversible inhibitors of chymotrypsin in the dark, and irreversible ones in the light. Photoaffinity labelling of chymotrypsin has been reported by the authors in FEBS Letters 46, 347 (1974).
Carotinoidsynthesen über Sulfone; Synthese von Apocarotinoiden und Torularhodinester
Authors: Fischli Albert , Mayer Hans 
Published: December 2004

AbstractThe alkylation of conjugated arylsulfonyl ylids, prepared from the corresponding allylic sulfones (2 or 8), and allylic halides bearing terminal carbonylgroups (3 or 4) leads to polyene sulfones which readily undergo spontaneous elimination of the corresponding aryl sulfinates. By this method two apocarotenoids (5 and 6) and torularhodin ethyl ester (9) have been prepared.
Hormon‐Rezeptor‐Wechselwirkungen. Synthese von α‐Melanotropin und von informationstragenden Teilsequenzen unter Verwendung alkalilabiler Schutzgruppen
Authors: Eberle Alex , Fauchère Jean‐Luc , Tesser Godefridus Ignatius , Schwyzer Robert 
Published: December 2004

Hormone‐Receptor Interactions. Synthesses of α‐Melanotropin and of Informational Sequences thereof with the Aid of Alcali‐Labile Protecting Groups.The aim of this investigation was to prepare α‐melanotropin and partial sequences thereof for biological investigations in as pure a state as possible. Classical synthesis in solution was chosen as the general approach, because it allows for extensive purification and identification of all intermediates, thus warranting the chemical identity of the products (in contrast to the solidphase methods). The scheme of protection was as follows: for the Nα‐amino groups mostly t‐butoxycarbonyl (BOC‐), sometimes benzyloxycarbonyl (Z‐), for the Nϵ‐amino group of lysine‐(11) 2‐(methylsulfonyl)‐ethoxycarbonyl (MSOC‐), and for the carboxylic acid group of C‐terminal glycine‐(10) 2‐(4‐tolyl‐sulfonyl)‐ethoxy (‐OTSE). This provides for facile and mild selective deprotection of either the α‐amino groups by acidolysis or of the ϵ‐amino group (α‐carboxyl group) by β‐elimination in alcali. A slight molar excess of 0.12N HCl in HCOOH proved to be the method of choice for removing BOC‐; MSOC‐ is stable in acid (even for 30 min in liquid HF) and easily removed in a few minutes by 0.05‐‐0.1N Ba(OH)2; ‐OTSE is removed similarly. Condensation of amino‐acid and peptide derivatives (formation of the peptide link) was performed using active esters (‐ONP; ‐OSU), dicyclohexyl‐carbodiimide (DCCI) with or without 1‐hydroxy‐benzotriazole (HOBT), or carboxylic acid azides wherever histidine was the carboxylic component.More than 50 compounds are described. Those characterized by arabic numerals served to prove that α‐MSH contains two message sequences that are able to trigger melanocyte response: one in the central region ‐His‐Phe‐Arg‐Trp‐, the other in the C‐terminal portion ‐Gly‐Lys‐Pro‐Val · NH2 of the molecule [3].
Etude par spectrométrie de masse de la fragmentation des cyclopentane‐triols‐1,2,3, des cyclopentane‐tétrols et des cyclopentane‐pentols
Authors: Singy Gérard A. , Buchs Armand 
Published: December 2004

AbstractThe mass spectra of the three cyclopentane‐1,2,3‐triols, six cyclopentane‐tetrols and four cyclopentane‐pentols stereoisomers have been studied. Complex processes, especially regarding the H2O eliminations, were detected by extensive deuterium labelling.
Piperaceae alkaloids: Part IV. Structure and Synthesis of Cyclostachine A, Cyclostachine B and Cyclopiperstachine
Authors: Joshi Balawant S. , Viswanathan Narayanan , Gawad Dilip H. , Balakrishnan Venkatachalam , von Philipsborn Wolfgang 
Published: December 2004

AbstractThree new alkaloids designated as cyclostachine A (2), cyclostachine B (7) and cyclopiperstachine (10) have been isolated from Piper trichostachyon C. DC. Their structures have been derived on the basis of spectral and degradative studies and confirmed by synthesis. The 1H‐ and 13C‐NMR. spectra of these compounds are discussed.
Ene‐sulfides as Reaction Partners of Organometallic Compounds
Authors: Muthukrishnan Ramamurthi , Schlosser Manfred 
Published: December 2004

AbstractA comparison of the reactivity of ene‐sulfides and en‐ethers towards organometallic reagents reveals some remarkable differences. With the thio compounds metallation at the olefinic site next to the hetero atom dominates clearly over the alternative deprotonation of an allylic position. Only with propenyl phenyl sulfide both exchange modes were observed simultaneously, whereas with all higher homologues of it as well as vinyl phenyl sulfide the metal was exclusively attached to the olefinic α‐carbon atom.
Action du monoxyde d'azote sur le trichloréthylène et sur le tétrachloréthylène
Authors: Tuaillon Jacques , Perrot Roger 
Published: December 2004

The Action of Nitrogen Monoxide on Trichloro‐and Tetrachlor‐Ethylene.Under the sun light and at room temperature nitric oxide reacts with trichlorethylene and tetrachlorethylene giving monomer nitroso nitrated compounds. These compounds can also be obtained through reaction of dinitrogen trioxide with trichlorethylene and tetrachlorethylene.The nitrating and oxidizing properties of nitric oxide can be considered through these reactions:– Trichlorethylene leads to: pentachlorethane,1,1,1,2‐tetrachlor‐2‐nitroethane, dichloracetic acid and 1,1,3,3‐4‐pentachloro‐4‐nitro‐1‐butene: CO2 and CO are also observed.–Tetrachlorocthylene gives : hexachlorethane, tetrachloro‐2pentaclorethyl‐1,2‐oxazetidine; carbon tetrachlorid and trichloracetylchlorid arc obtainetl in very little yiclcl. These results prove that oxidizing cleavage may occur.Kitric oxitl reacts giving nitrogen as main gazcous product, prouved by gas liquid chrornatography.
p‐Hydroxybenzylierung von Carbanionen mit Chinonmethid‐liefernden Verbindungen
Authors: Schmidt Andreas , Brunetti Heimo 
Published: December 2004

p‐Hydroxybenzylation of Carbanions with Quinonemethide Precursors.3,5‐Dialkylated 4‐hydroxy‐benzyl derivatives 4, 5 and 6 are useful starting materials for the p‐hydroxybenzlation of carbanions derived from activated methylene compounds 7. The reaction presumably proceeds through intermediate formation of quinonemethides 2. The scope of the reaction is discussed.