bluuebunny/crossref_metadata_2025_split huggingface dataset:
Einsatz von Hochleistungs‐Trennkapillaren in der GC.‐EIMS./GC.‐CIMS.‐Analyse: Eine Möglichkeit zur massenspektrometrischen Doppelbindungscharakterisierung in komplexen Monoalkengemischen
Authors: Blum Wolfgang , Richter Wilhelm J. 
Published: December 2004

AbstractIn an attempt to determine position and substitution of double bonds in complex mixtures of straight‐chain and branched monoalkenes without actually isolating the constituents, GC.‐MS. analysis is performed after in‐batch preparation of derivatives of a judiciously chosen type. Cyclic phenylboronates (4,5‐substituted 2‐phenyl‐1,3,2‐dioxaborols) are prepared from 1,2‐diols which are, in turn, obtained from the original alkenes by treatment with osmium tetroxide. Chemical ionization mass spectrometry (CIMS.) is used in addition to conventional electron impact techniques (EIMS.) in sequential GC./CIMS.‐ and GC./EIMS.runs, yielding complementary structural information for the single components of the mixture. In order to cope with the potential severity of the separation problem, high‐efficiency glass capillary columns were employed throughout. The performance of the system used is demonstrated by a complete double bond analysis of a 35‐component mixture of monoalkenes in the C5 to C9 range.
Etude par résonance paramagnétique électronique du radical (ΦNH)2P• piégé dans un monocristal de diphenylamino‐phosphineoxyde irradié aux rayons X
Authors: Ginet Lucien , Geoffroy Michel 
Published: December 2004

AbstractThe radical (ΦNH)2P· is trapped by annealing at 100°C an X‐irradiated single crystal of NN diphenyl phosphondiamide and has been studied by electron spin resonance. The isotropic and anisotropic 31P coupling constants are discussed. The principal values and direction cosines of the g tensor are also given.
A Short Stereoselective Total Synthesis of Racemic Patchouli Alcohol. Preliminary communication
Authors: Näf Ferdinand , Ohloff Günther 
Published: December 2004

AbstractA stereoselective four‐step synthesis of racemic patchouli alcohol starting from the known 2,6,6‐trimethyl‐2,4‐cyclohexadien‐1‐one [1] and 3‐methylpent‐4‐en‐1‐ol [2] is described.
Arbeiten über Phosphorsäure und Thiophosphorsäureester mit einem heterocyclischen Substituenten 9. Mitteilung 1. Aza‐Analogie I: Aza‐Analoge von Phthalimid‐, Benztriazol‐ und 1,2,3‐Benztriazin‐4(3H)‐on‐Derivaten
Authors: Rüfenacht Kurt 
Published: December 2004

AbstractAza‐analogues of the known pesticidal dithiophosphates 2, 4 and 5 have been prepared by replacing the phthalimide, benzotriazole and 1,2,3‐benzotriazin‐4(3H)‐one moieties resp. in 2 by those of quinolinic acid imide (6), cinchomeronic acid imide (7) and pyrazine‐2,3‐dicarboxylic acid imide (12), in 4 by 1H‐v‐triazolo[4,5‐b]pyridine (15) and in 5 by pyrido[2,3‐e]1,2,3‐triazin‐4(3H)‐one (21). Compared to the known compounds the new esters are less or at best equally pesticidal with an equal or even higher mammalian toxicity.
Preparation of Neutral Ionophores for Alkali and Alkaline Earth Metal Cations and their application in ion selective membrane electrodes
Authors: Ammann Daniel , Bissig René , Güggi Marc , Pretsch Ernö , Simon Wilhelm , Borowitz Irving J. , Weiss Louis 
Published: December 2004

AbstractThe preparation of a series of non‐cyclic, uncharged ligands able to selectively complex alkali and alkaline earth metal cations is described. These molecules are designed to be used as carriers for cations through membranes. Some of the compounds show high Ca2+ and Na+ selectivity, respectively, in liquid membrane electrodes.
Piperaceae Alkaloids: Part I. Structure of piperstachine; 13C‐ and 1H‐NMR. Studies
Authors: Joshi Balawant S. , Viswanathan Narayanan , Gawad Dilip H. , von Philipsborn Wolfgang 
Published: December 2004

AbstractFrom the stem of Piper trichostachyon C. DC. a new alkaloid designated piperstachine (VII) has been isolated. Its structure is derived on the basis of spectral data and synthesis of hexahydropiperstachine (X).
The He 584 Å Photoelectron Spectra of Analoga of Thiathiophthene
Authors: Gleiter Rolf , Gygax Ruedi , Reid David H. 
Published: December 2004

AbstractThe photoelectron spectra of the four oxygen and nitrogen analogs of thiathiophthene 1 to 4 are reported and discussed. The first two bands are assigned to ionization from the π‐ and n‐molecular orbitals on the basis of CNDO/2 calculations. The assignment of bands and to ionization from π‐molecular orbitals is suggested.
Selektive Funktionalisierung von Wortmannin mit Hilfe einer Furanring‐Maskierung
Authors: Haefliger Walter , Kis Zoltan , Hauser Daniel 
Published: December 2004

AbstractWortmannin (1) and its 11‐desacetoxy derivative 2 are highly susceptible to nucleophiles, which limits the possibilities of transformation. Masking the furan ring by a new method allowed selective transformations with various reagents.
Total Synthesis of Indole and Dihydroindole Alkaloids. VI. The total synthesis of some monomeric vinca alkaloids: dl‐Vincadine, dl‐vincaminoreine, dl‐vincaminorine, dl‐vincadifformine, dl‐minovine and dl‐vincaminoridine
Authors: Kutney James P. , Chan Ka Kong , Failli Amedeo , Fromson John M. , Gletsos Constantine , Leutwiler Albert , Nelson Vern R. , de Souza Joao Pedro 
Published: December 2004

AbstractA synthetic approach to a variety of monomeric Vinca alkaloids is described. The sequence involves, among its crucial phases, the generation of appropriate nine‐membered ring intermediates which are then elaborated via a transannular cyclization approach to the desired natural products.
Total Synthesis of Indole and Dihydroindole Alkaloids. VII. The total synthesis of isovelbanamine, velbanamine, cleavamine, 18β‐carbomethoxycleavamine and catharanthine
Authors: Kutney James P. , Bylsma Feike 
Published: December 2004

AbstractA synthesis of a variety of nine‐membered ring intermediates in the cleavaminevelbanamine series is described. The formation of the penultimate intermediate involves a fragmentation reaction in which the cleavamine system is generated from an appropriate rigid pentacyclic Iboga alkaloid derivative. Thus dihydrocatharanthinol tosylate (VIII) on reaction with triethylamine in refluxing benzene undergoes fragmentation to the 5, 18‐seco‐diene X. This latter substance is then elaborated in various ways to the desired compounds.
Darstellung und Charakterisierung von (±)‐Coralydin und (±)‐O‐Methylcorytenchirin und ihrer optischen Antipoden (Vorläufige Mitteilung)
Authors: Bruderer Hans , Metzger Jean , Brossi Arnold 
Published: December 2004

AbstractThe synthesis and characterization of (±)‐coralydine and (±)‐O‐methylcorytenchirine and their optical isomers are described.
Steroide und Sexualhormone 256. Mitteilung 1. Quassinoide Bitterstoffe I 1‐Oxo‐2‐methoxy‐4α‐methyl‐17β‐hydroxy‐Δ2‐5α‐androsten als Modell für den Ring A des Quassins
Authors: Jörg Koch Hans , Pfenninger Hans , Graf Walter 
Published: December 2004

AbstractStarting from 3‐oxo‐17β‐hydroxy‐Δ1‐5α‐androstene (2b) the preparation of 1‐oxo‐2‐methoxy‐4α‐methyl‐17β‐hydroxy‐Δ2‐5α‐androstene (9), a compound with the ring A structure of quassine (1) is described. The key problem of the reaction sequence is shown to be the monomethylation at C(4).
Dérivés C‐glycosyliques XXVI. Nouvelles voies d'accès à des C‐nucléosides isoxazoliques et thiophéniques Communication préliminaire
Authors: Tronchet Jean M. J. , Martin Olivier , Zumwald Jean‐Bernard , Le‐Hong Nghiep , Perret Françoise 
Published: December 2004

Abstract3‐O‐benzyl (and 3‐O‐methyl)‐1,2‐O‐isopropylidene‐α‐D‐xylo‐dialdo‐1,4‐furanoses treated with bromocyanomethylidene‐ or bromoacylmethylidene‐triphenylphosphoranes gave in good yields the corresponding olefinic sugars. These compounds, which bear three adjacent electrophilic carbon atoms (C(5), C(6), C(7)) constitute useful synthetic intermediates in carbohydrate chemistry. They represent, for example, good starting materials for the preparation of 3‐glycosylisoxazoles, 5‐glycosylisoxazoles and 2‐glycosylthiophenes.
Die stereospezifische Reduktion von (1R)‐3‐endo‐Aminocampher zu (1R)‐3‐endo‐Aminoborneol
Authors: Pauling Horst 
Published: December 2004

AbstractThe highly stereospecific reduction of (1R)‐3‐endo‐aminobornan‐2‐one (2) to [1R]‐3‐endo‐amino‐2‐endom‐bornanol (1) is described. This reaction is achieved by using alkylaluminumdichlorides, a new group of reducing agents for the reduction of the ketone 2 to the secondary alcohol 1Diesc Reduktion ist Gegenstand van Patcntanmeldungen, z. B. [l].
Totalsynthese von Betalainen
Authors: Hermann Kurt , Dreiding André S. 
Published: December 2004

AbstractA total synthesis of betalaine pigments (6) is described. The key intermediate is betalamic acid in the form of its dimethyl ester semicarbazone (9), which was transformed with L‐proline (16) into indicaxanthine dimenthl ester (5), with L‐cyclodopa methul ester (17) into betanidine trimethyl ester (3) and by hydrolysis of the latter into betanidine (2).
Triasteranetrione from Triasteranedione
Authors: Chapleo Christopher B. , McDonald Ian A. , Dreiding André S. 
Published: December 2004

AbstractReaktion von Triasterandion (1) mit N‐Bromsuccinimid ergab 44% 9‐Brom‐triasterandion (5), neben wenig 9,9‐Dibrom‐triasterandion (6). Substitution des Bromatoms in 5 durch eine Acetoxygruppe ergab 74% 9‐Acetoxy‐triasterandion (10). Umesterung mit Natriumäthylat und Oxydation des rohen Hydroxy‐diketons 9 führte zu Triasterantrion (2). Versuche, Triasteranon (11) mit N‐Bromsuccinimid in 3,5‐Dibrom‐triasteranon (7) umzuwandeln, waren ohne Erfolg.
Synthèse de spiro‐pyrazolines par cycloaddition du diazométhane sur des sucres insaturés ramifiés. Influence de l'isomérie géométrique sur l'orientation de la réaction Communication préliminaire
Authors: Tronchet Jean M. J. , Gentile Bernard , Tronchet Jeannine 
Published: December 2004

AbstractThe orientation of the cycloaddition of diazomethane on unsaturated branchedchain sugars has been studied. For 3‐C‐cyanomethylidene‐3‐deoxy‐1,2‐O‐isopropylidene‐α‐D‐glycero‐tetrofuranose the orientation was ‘normal’ and did not depend on the configuration at the double bond. The same situation prevailed with derivatives of 3‐deoxy‐1,2:5,6‐di‐O‐isopropylidene‐3‐C‐methylidene‐α‐D‐xylo‐hexofuranose. For the 3‐C‐acylmethylidene‐ and the 3‐C‐cyanomethylidene‐3‐deoxy‐1,2:5,6‐di‐O‐isopropylidene‐α‐D‐ribo‐hexofuranoses, the trans‐(H–C(3′)–C(2))‐isomer gave the ‘normal’ cycloadduct whereas the cis‐isomer gave predominantly the αabnormal spiro‐pyrazoline. This observation represents the first instance where the regioselectivity of a cycloaddition reaction is affected by the geometrical isomerism of the dipolarophile. The most probable explanation of the phenomenon is the conformational perturbation about the C(4)‐‐C(5) bond of the unsaturated sugars induced by a change in the configuration at C(3). The consequence of that ‘conformational transmission’ of a difference in configuration at C(3) is that the steric crowding on the cis‐ than in the trans‐isomer. Several novel examples of a new series of C‐glycosylidenic derivatives, the spiro‐pyrazolines, are described.
Synthese und HOFMANN‐Abbau des 1‐(Diphenyl‐hydroxymethyl)‐2,2‐dimethyl‐6,7‐dimethoxy‐1,2,3,4‐tetrahydroisochinolinium‐Ions
Authors: Wiegrebe Wolfgang , Rohrbach‐Munz Barbara , Awe Walter , Kirk Olaf 
Published: December 2004

AbstractThe synthesis of the N‐quaternary aminoalcohol 6 is described. Analogous to the aminoalcohols 1 and 2, 6 on treatment with alkali undergoes fission of the substituent at C(1) as a carbonyl compound, with formation of a N, N‐dimethyl‐1,2,3,4‐tetrahydroisoquinolinium ion, which is further degraded to the corresponding o‐vinyl‐benzylamine (Scheme1). – As a by‐product of a Bischler‐Napieralski ring closure, we observed chlorination of an aromatic ring (yielding 19).
Synthesis of Heparin Saccharides III. Synthesis of Derivatives of D‐Glucosamine as Starting Materials for Disaccharides
Authors: Wyss Pierre C. , Kiss Joseph 
Published: December 2004

AbstractDerivatives of benzyl 2‐[1‐(benzyloxy)formamido]‐2‐deoxy‐α‐D‐glucopyranoside with various protecting groups at C(3) (benzoyl, benzyl and N‐phenylcarbamoyl) and C(6) (benzoyl, benzylsulfonyl, N‐phenylcarbamoyl and tosyl) have been synthesized as starting materials for disaccharides. The C(4) and C(6) hydroxyl groups of the amino sugar were initially blocked by an acetal group. After introduction of the protecting group at C(3), the acetal group was removed by acid hydrolysis, and the C(6) hydroxyl group was selectively acylated or sulfonylated. The 3,6‐di‐O‐benzoate has also been prepared by dimolar benzoylation of the amino sugar, whereby the 4,6‐isomer was obtained as a by‐product.
Synthesis of Heparin Saccharides IV. Synthesis of disaccharides possessing the structure of a repeating unit of heparin
Authors: Wyss Pierre C. , Kiss Joseph , Arnold Wolf 
Published: December 2004

AbstractThe synthesis of disaccharides possessing the structure of a repeating unit of heparin is reported. 2‐Acetamido‐2‐deoxy‐4‐O‐(methyl α‐D‐glucopyranosyluronate)‐D‐glucopyranose (1) and 2‐[1‐(benzyloxy)formamido]‐2‐deoxy‐4‐O‐(methyl α‐D‐glucopyranosyluronate)‐D‐glucopyranose (2) have been prepared by two routes, (a) from D‐glucose and D‐glucosamine, and (b) from D‐glucuronolactone and D‐glucosamine.
A Transient Ion Pair (CCl · Cl−) in Irradiated Liquid CCl4: Evidence for a ‘delayed’ geminate ion neutralisation. (Preliminary communication)
Authors: Bühler Rolf E. , Hurni Bendicht 
Published: December 2004

AbstractDetailed cation scavenger studies in pulse‐irradiated pure, liquid CCl4 reveal that the 500 nm absorption has both, neutral and cationic characteristics, and that CCl4+ must be the precursor. It is shown that all experimental results are compatible with the following ion neutralisation mechanism: CCl + Cl− → (CCl · Cl−) → CCl4.The 500 nm band is assigned to the CCl3+‐cation (free or complexed). Its neutralisation therefore does not occur on ion recombination, but is delayed by the life time of the ion pair: τ½ (ion pair) = 33 ± 3 ns at −22°C with activation energy of 10.9 ± 2.1 kJ/mol. Possible reasons for the ion pair stability are briefly discussed.
Synthese der diastereomeren 4‐Amino‐ und 4‐Hydroxy‐3‐(p‐chlorphenyl)‐valeriansäuren. Kristallstruktur von cis‐4‐(p‐bromphenyl)‐5‐methyl‐2‐pyrrolidinon
Authors: Bruderer Hans , Arnold Wolf , Oberhänsli Willy E. 
Published: December 2004

Synthesis of 4‐amino‐ and 4‐hydroxy‐3‐(p‐chlorophenyl)‐valeric acids. X‐ray structure of cis‐4‐(p‐bromophenyl)‐5‐methyl‐2‐pyrrolidinoneThe syntheses of diastereomeric 4‐amino‐ and 4‐hydroxy‐3‐(p‐chlorophenyl)‐valeric acids and of their ring closure products (lactones and lactams), starting from 3‐(p‐chlorophenyl)‐4‐oxo‐valeric acid, are described. A single‐crystal X‐ray structure analysis of cis‐4‐(p‐bromophenyl)‐5‐methyl‐2‐pyrrolidinone is given. Some aspects of the biochemistry of threo‐3‐(p‐chlorophenyl)‐4‐amino‐valeric acid are presented.
11. Anil‐Synthese. 16. Mitteilung. Über die Herstellung von styryl‐derivaten des 2‐phenyl‐imidazo [1,2‐a]pyridins
Authors: Pauchard Jean‐Paul , Siegrist Adolf Emil 
Published: December 2004

Preparation of styryl derivatives of 2‐phenyl‐imidazo [1, 2‐a]pyridine2‐(p‐Tolyl)‐imidazo [1, 2‐a]pyridines and 7‐methyl‐2‐phenyl‐imidazo [1,2‐a]‐pyridines can be converted, in dimethylformamide, on reaction with anils of aromatic aldehydes in the presence of potassium hydroxide or potassium t‐butoxide, into the corresponding 2‐(stilben‐4‐yl)‐ and 2‐phenyl‐7‐styry1‐imidazo [1, 2‐a]‐pyridines (‘Anil‐Synthesis’). The 2‐(p‐tolyl)‐imidazo [1,2‐a]pyridines react far less readily than the 7‐methyl‐2‐phenyl‐imidazo[1,2‐a]pyridines.
Triplet‐Triplet Absorption Spectroscopy of Some Highly Dipolar Unsaturated Nitro Compounds
Authors: Cowley David J. 
Published: December 2004

AbstractThe triplet‐triplet absorption spectra of p‐N, N‐dimethylnitroaniline, 4‐nitro‐p‐terphenyl, 1‐amino‐4‐nitrofluorene, 5‐nitroacenaphthene, trans‐1‐(4‐methoxy‐phenyl)‐2‐nitroethylene (MeONS), and trans‐1‐(4‐dimethylaminophenyl)‐2‐nitroethylene (DANS) in EPA glass at 77 K are reported, together with molar extinction coefficients and PPP‐SCF‐MO‐CI calculations. The two nitrostyrenes, MeONS and DANS, have been examined in fluid media at room temperature using nanosecond laser photolysis, and their triplet lifetimes found to increase substantially with increase in solvent polarity and charge‐transfer character of the compound. This is interpreted in terms of the diradical/zwitterionic nature of the triplet state affecting the T1–S0 energy gap at the 90° twisted configuration of the olefinic linkage.The decrease in both the triplet yield and the fluorescence yield of DANS with increase in solvent polarity is explained by the intervention of an internal conversion process involving a rotation of the dimethylamino group in the lowest singlet excited state.
A New Synthesis of 2,3,1‐Diazaborines
Authors: Müller Beat W. 
Published: December 2004

AbstractA new method for the preparation of 2,3,1‐diazaborines is described. It is suggested that the observed formation of the C,B‐bond by electrophilic attack with a boron halide is facilitated and o‐directed by the sulfonyl hydrazone group of the educts.
Inhaltsstoffe des Osmanthus‐Absolues. 2. Mitteilung: 2,7‐Epoxy‐megastigma‐4,8(E)‐dien
Authors: Kaiser Roman , Lamparsky Dietmar 
Published: December 2004

Constituents of Osmanthus Absolute, 2nd communication: 2,7‐Epoxy‐megastigma‐4,8 (E)‐dieneThe characteristic fragmentation pattern in the mass spectrum of 2,7‐epoxy‐dihydro‐α‐ionone bearing a new oxabridged ionone skeleton has lead to the identification of a further trace component in Osmanthus absolute, the 2,7‐epoxy‐megastigma‐4,8(E)‐diene. The synthesis was performed in three steps starting from the above mentioned new ionone derivative now synthetically available by base treatment of 2‐hydroxy‐α‐ionone [1].
Inhaltsstoffe des Osmanthus‐Absolues. 3. Mitteilung: Derivate der theaspirane
Authors: Kaiser Roman , Kappeler Annemarie , Lamparsky Dietmar 
Published: December 2004

Constituents of Osmanthus‐Absolute, 3rd communication: Derivatives of TheaspiranesFour isomeric new 7‐oxo‐dihydrotheaspiranes were identified in Osmanthus absolute. Their configuration was proved by synthetic correlations with racemic as well as optically active theaspiranes A and B. These two compounds also occurring in the same natural substrate were first correlated with the (−)‐theaspirone A of known absolute configuration and the (+)‐theaspirone B, respectively, thus giving the background for all further stereochemical relationship work. In depth studies in the 1H‐ and 13C‐NMR.‐spectroscopy field including all possible and now synthetically available hydroxy derivatives of the new oxo compounds enabled us to unambiguously assign structures 1 to 4 to the natural products. Some further constituents bearing the same spirocyclic skeleton were also detected in Osmanthus absolute.
CH‐Acidität in α‐Stellung zum N‐Atom in N,N‐dialkylamiden mit sterisch geschützter Carbonylgruppe zur nucleophilen minoalkylierung
Authors: Schlecker Rainer , Seebach Dieter , Lubosch Winfried 
Published: December 2004

CH‐Acidity in α‐position to the N‐Atom of N, N‐Dialkylamides with Sterically Protected Carbonyl Groups Contribution to the Nucleophilic Amino AlkylationSterically protected amides 1 such as the 2,4,6‐triisopropyl‐benzoic acid derivatives 3, 8b and 10 undergo readily H/Li‐exchange with s‐butyllithium at the CH3N‐ or CH2N‐groups. The resulting organolithium compounds (cf. 9, 11) are alkylated and hydroxyalkylated with primary haloalkanes, aldehydes, and ketones under chain elongation in the amine position of the amides. The (E/Z)‐rotamers of the dialkylamides 7 and 8are separated by chromatography; the amides 4–6, 12, and 13 formally derived from β‐hydroxyamines are obtained in the (Z)‐form only. The configurational (E/Z)‐assignments follow from NMR. and IR. data. The erythro and threo configuration of the two diastereomeric amides 12a and 12b are tentatively concluded from Eu(fod)3‐1H‐NMR.‐shift experiments. The results strongly suggest that the H/Li‐exchange takes place regioselectively at the CHN group which is in cis‐position to the CO double bond (→14). The methyl 2,4,6‐tri(t‐butyl)benzoate (18) can also be deprotonated to the lithium acyloxymethanide 19 which is trapped by alkylation with 1‐iodooctane (→20). – The steric protection of the carbonyl groups in the products 4–8, 10, 12, 13, and 20 prevents their ready hydrolysis to amines and alcohols, respectively. Therefore, triphenylacetic acid derivatives 21 rather than 2,4,6‐triisopropylbenzoic acid derivatives for use in the electrophilic substitution of equation (1) are recommended. The trityl group in 21 may be considered a C‐leaving‐group (CC protective group, cf. 22, 23). The acetamide 25 reacts readily (→26) and then with electrophiles to give products 27a–c. As shown in the Table, the amides 27 are cleaved under a variety of conditions with formation of triphenylmethane. LiAlH4 produces a tertiary amine, CH3Li a secondary amine, and dissolving alkali metals/naphthalene under aprotic conditions mixtures of secondary amine and its formamide (hydrolysed by acid treatment). Thus the overall process (2) is feasible.
Das Zweiphasenystem Oxinschmelze/Wasser zwischen 75 und 100°
Authors: Magyar Balazs , Vonmont Heinz 
Published: December 2004

The two phase system oxyne melt/water between 75 and 100°The density, mutual solubility of oxine and water were determined. Using these data the volumes of the coexisting phases can be calculated from the originally weight‐in quantity of oxine and water in extraction experiments. The acidity constants of oxine between 65 and 95° were also determined and the temperature dependence of the pK‐values is discussed.
Triazènes et benzotriazines dérivés de sucres
Authors: Tronchet Jean M. J. , Rachidzadeh Faranak 
Published: December 2004

AbstractSugar triazenes and benzotriazinesSeveral triazenylsugars have been prepared, generally in good yields, by treating an amino sugar with a substituted benzenediazonium salt. The triazenylsugars bearing a hydrogen atom on the triazenyl group are acetylated on the nitrogen atom closest to the glycosyl moiety (N(1)), even when the proton exchanged sites between N(1) and N(3). When an acetyl or a methoxycarbonyl group was present in the ortho position of the benzene ring cyclization took place leading to a 3,4‐dihydro‐4‐methylidene‐1,2,3‐benzo[d]triazine or a 3,4‐dihydro‐1,2,3‐benzo[d]triazin‐4‐one respectively.
Stereospezifische Fragmentierungen in den Massenspektren von Cyclohexandiaminen und Bis(aminomethyl)cyclohexanen. 33. Mitteilung über massenspektrometrische Untersuchungen,,
Authors: Süess Hans , Hesse Manfred 
Published: December 2004

Stereospecific Fragmentations in the Mass Spectra of Cyclohexanediamines and Bis(aminomethyl)cyclohexanesThe mass spectral behaviour, especially loss of NH3, of the six isomeric cyclohexanediamines 1‐‐3 (cis and trans each, Scheme 1) as well as of the six isomeric bis(aminomethyl)cyclohexanes 4‐‐6 (cis and trans each, Scheme 6) has been investigated. The cis‐ and trans‐compounds of the 1,2‐isomers 1 and 4 show very similar spectra, because of the ease of ring cleavage at C(1)–‐C(2) and the similar geometrical relations in all ring conformations. The cis‐ and trans‐compounds of both the 1,3‐ and 1,4‐isomers 2, 3, 5 and 6 show striking differences in their mass spectra due to stereospecific elimination of NH3 from the molecular ion.
The Absolute Configuration of 1‐Methylindane
Authors: Hansen Hans‐Jürgen , Sliwka Hans‐Richard , Hug Werner 
Published: December 2004

AbstractIt is shown unequivocally by chemical correlations (cf. Schemes 1‐‐3) and Raman optical activity spectra (cf. Fig. 1 and 2) that the (R)‐configuration has to be attributed to (+)‐1‐methylindane ((+)‐1). This is in contradiction to an earlier assignment of the (R)‐configuration to (−)‐1[2] which was based on the (R)‐configuration of (+)‐indane‐1‐carboxylic acid (3) [11].