bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthese von 3‐(2,4,5‐Trihydroxyphenyl)‐DL‐alanin
Authors: Langemann A. , Scheer M.
Published: December 2004

Condensation of 2.4.5‐trimethoxybenzaldehyde with hydantoin followed by catalytic hydrogenation gave 5‐(2.4.5‐trimethoxybenzyl)‐hydantoin, which was converted to 3‐amino‐3.4‐dihydro‐6.7‐dihydroxycoumarin by treatment with hydrobromic acid. Hydrolysis of the lactone led to 3‐(2.4.5‐trihydroxyphenyl)‐DL‐alanine.
Synthese von Haschisch‐Inhaltsstoffen. 4. Mitteilung
Authors: Petrzilka T. , Haefliger W. , Sikemeier C.
Published: December 2004

(−)‐Cannabidiol has been synthesized from (+)‐cis‐ and (+)‐trans‐p‐menthadien‐(2, 8)‐ol‐(1) and olivetol, using N, N‐dimethylformamide dineopentyl acetal or weak acids, such as oxalic, picric, or maleic acid, as catalysts.

Since the chirality of (+)‐trans‐p‐menthadien‐(2, 8)‐ol‐(1) is known, the above synthesis constitutes an unambiguous prove for the absolute configuration of (−)‐cannabidiol and the two isomeric (−)‐6a, 10a‐trans‐tetrahydrocannabinols.

If stronger acids, such as p‐toluenesulfonic, trifluoroacetic, or hydrochloric acid, are used as mediators for the reaction, (−)‐Δ8‐6a, 10a‐trans‐tetrahydrocannabinol is obtained as the main product.

Transformation of the thermodynamically more stable Δ8‐tetrahydrocannabinol into the less stable Δ9‐isomer was achieved in a practically quantitative yield by addition of hydrochloric acid and elimination of the elements of hydrochloric acid by means of potassium t‐amylate. If resorcinols I were used instead of olivetol in the condensation reaction with strong acids, the corresponding homologues of Δ8‐tetrahydrocannabinol were obtained in varying yields.
Über 9β,10α‐Steroide. 4. Mitteilung [1]. Strukturaufklärung von mikrobiologischen Umsetzungsprodukten
Authors: Els H. , Englert G. , Fürst A. , Reusser P. , Schocher A. J.
Published: December 2004

The structure and the stereochemistry of some 8‐ and 9‐hydroxy‐9β, 10° (retro)‐steroids of the androstane and pregnane series, obtained microbiologically, have been elucidated.
α‐Santonin: Photochemie in protischen Lösungsmitteln und Pyrolyse
Authors: Schaffner‐Sabba K.
Published: December 2004

In protic media of the type ROH and RCOOH irradiation of α‐santonin yields addition products of the isophotosantonic‐lactone type 3 apart from lumisantonin (2) and in some cases its photoproducts. The amount of 3 depends on the acidity of the solvent up to a limiting value, above which exoanhydro‐isophotosantonic‐lactone (5) is also formed.

Under pyrolytic conditions α‐santonin is in equilibrium with pyrosantonin (14), the structure of which is discussed.
Die Pyrolyse von (+)‐Verbenen
Authors: Thomas Alan F. , Willhalm B. , Ohloff G.
Published: December 2004

The pyrolysis of verbenene has been found to give rise to 39% of isobutenylcyclohexa‐1,3‐diene (3), 29% of o‐mentha‐1 (7),5,8‐triene (2) together with two double bond‐isomers (4 and 5) of the cyclohexadiene (3). The structures were proved by catalytic reduction to the saturated hydrocarbons, and isobutenylcyclohexa‐1,3‐diene was synthesized from 2,3‐dihydrobenzaldehyde.
Die absolute Konfiguration von Carquejol und verwandten o‐Menthan‐Derivaten
Authors: Snatzke G. , Thomas A. F. , Ohloff G.
Published: December 2004

The structure of carquejol is amended to that of cis‐3‐hydroxy‐o‐mentha‐1(7),4,8‐triene; the chirality has been confirmed as 2 R, 3 S by correlation with the (−)‐cis‐o‐menthane obtained from carquejol and that from (+)‐verbenene of known absolute configuration.

The two double bonds of the dihydrocarquejol system (15 and 16) constitute a helical system, that especially in the case of the acetate (16) fixes the isopropenyl group in such a way that a very high Δϵ value in the CD. curve is observed. The conformational significance of this phenomenon is discussed.
Fluoreszierende Stoffe aus Roten Waldameisen der Gattung Formica (INS. HYM). 6. Mitteilung [1]. Einige chemische Eigenschaften des Formicapterins
Authors: Viscontini M. , Konishi M.
Published: December 2004

Formicapterin wurde aus Formica rufa und F. polyctena isoliert. Die Ergebnisse der physikalisch‐chemischen Messungen und der Abbaureaktionen, die am verfügbaren Material ausgeführt wurden, erlauben noch keine endgültige Aussage über die Struktur des Formicapterins, das vermutlich ein polyhydroxyliertes Lumazin ist.
Struktur der Blei(IV)‐carboxylate und ihre Zersetzung über elektronenspinresonanz‐spektroskopisch nachweisbare Radikalzwischenstufen
Authors: Heusler K. , Loeliger H.
Published: December 2004

The position of the asymmetric COO‐ vibration of lead4+ carboxylates (at 6.50 to 6.58 μ) clearly indicates the absence of covalent bonding between oxygen and lead. These salts show strong UV. absorption in the region of 220 to 270 nm which is assigned to a charge transfer from oxygen to lead. UV.‐irradiation of lead4+ carboxylates at −196°C in a solid benzene matrix leads to decarboxylation and production of alkyl radicals which were identified by ESR. spectrometry. These radicals react in the solid matrix by hydrogen abstraction from the α‐position of a neighbouring carboxylate. In solution however rapid oxidation to carbonium ions occurs.
Das Problem der Mononitrierung von Durol
Authors: Hanna S. B. , Hunziker E. , Saito T. , Zollinger H.
Published: December 2004

In contrast to many previous investigations, reaction conditions were found under which the nitration of durene (nitrating ratio of 1:1) gives predominantly, and in high yield, mononitrodurene rather than the usually formed dinitrodurene (plus unreacted durene). The method consists in nitrating by nitronium phosphorohexafluoride in nitromethane as solvent in presence of two equivalents of water.

With mixed acid (HNO3 + H2SO4) in nitromethane and in acetonitrile durene forms also monoand no dinitrodurene; but under most conditions by‐products are formed. Some of the by‐products were identified.

Some preliminary mechanistic results are reported: An addition complex of unknown structure is formed rapidly; 3, 6‐dideuterodurene + D2O do not show a hydrogen isotope effect; the preferential formation of dinitrodurene under conventional conditions is due to the fact that the reaction occurs at encounter‐controlled rate.
Strahlungschemie von Kohlenwasserstoffen. 15. Mitteilung. Energieübertragung im System Benzol–3‐Phenylcyclohexadien‐(1,4)
Authors: Zimmerli Bernhard , Gäumann Tino
Published: December 2004

3‐Phenylcyclohexa‐1,4‐diene, which is a reaction product in the benzene radiolysis, is decomposed when its solutions in benzene are irradiated by γ‐rays. The main products are biphenyl (20%) and dihydrobenzene (10%). They show that hydrogen from phenylcyclohexadiene is transferred to benzene. The high G‐value for the disappearance is explained by energy‐transfer from a high‐lying state of benzene, formed with g(B*) ≥ 2, to the diene. From the concentration dependence in the range 0.015–0.25 Mol/1 can be concluded that τ · ktA is 21 1/Mole for phenylcyclohexadiene and 4 1/mole for cyclohexene, where τ is the lifetime of the excited state of benzene involved in the reaction and ktA is the rate constant for energy‐transfer from this excited state to the acceptor. This rate constant is in the same order of magnitude for biphenyl, naphthalene and cyclohexa‐1,4‐diene as accepted for phenylcyclohexadiene. The nature of the energy transfer from benzene to phenylcyclohexadiene is discussed. The possibilities of charge transfer or the lowest singlet‐ or tripletstate as excited states are ruled out.
Groupes de départ inhabituels lors de cyclisations dans la série des quinoxalines, II [1]
Authors: Dahn H. , Nussbaum Jeannine
Published: December 2004

Quinoxaline‐3‐ketones substituted by different groups in position 2 (I) are easily cyclized by hydroxylamine and phenylhydrazine to form isoxazolo[4, 5‐b] quinoxalines (II) and pyrazolo [3, 4‐b] quinoxalines (III) respectively. The reactions proceed via the oximes resp. phenylhydrazones. Groups displaced are not only the customary leaving groups of aromatic SN2 reactions (halogens, OH), but likewise H, COOH, CONH2, CO‐Ar, and, less easily, benzyl groups; methyl and phenyl groups were not displaced. The displacement of hydride ion in the presence of excess of hydroxylamine resp. phenylhydrazine is explained in terms of an extension of the theory of osazone formation.
Über die Chiralität der enantiomeren cis‐Tetrahydro‐actinidiolide
Authors: Ribi M. , Eugster C. H.
Published: December 2004

Ausgehend von (+) R‐α‐Cyclogeraniumsäure wurde die (+) R‐α‐Homocyclogeraniumsäure und daraus durch Jodlactonisierung und Hydrogenolyse (1R: 2 S)‐2, 6, 6‐Trimethyl‐2‐hydroxy‐cyclohexanessigsäure‐lacton ((+)‐cis‐Tetrahydro‐actinidiolid) hergestellt.
Etudes sur les composés organométalliques V [1]. Action de la pyridine sur les organomagnésiens
Authors: Dubsky George Jon , Jacot‐Guillarmod André
Published: December 2004

By the action of pyridine on various Grignard reagents at room temperature, new diorganomagnesium complexes R2Mg · 2pyridine (R=Ph, n‐Bu, t‐Bu and Et) were prepared and analyzed. Anomalous results were obtained with methyl‐ or benzylmagnesium reagents.
Calotropis‐Glykoside, vermutliche Teilstruktur.. Glykoside und Aglykone, 321. Mitteilung
Authors: Brüschweiler F. , Stöckel K. , Reichstein T.
Published: December 2004

Reduction of uscharidin (19) with NaBH4 gave a crystalline product C29H42O9 which we formulate as β‐tetrahydro‐uscharidin (12), it was characterised as a crystalline tri‐O‐acetyl‐derivative 14. The same compound 12 was obtained from calactin (18) and calotropin (18A), thus confirming earlier results of HESSE et al. about the close interrelationship of the three compounds. New formulae are suggested for the 7 Calotropis glycosides: calactin (18), calotropin (18A), uscharidin (19), calotoxin (20), procerosid (21), uscharin (31), and voruscharin (32). These formulae are consistent with the chemical reactions and spectra of the mentioned compounds. They are constructed in analogy to the formula of gomphoside (11) advanced by WATSON et al. with only an additional oxo group at C‐19.
Zur Thermodynamik der Metallcarbonate 3. Mitteilung [1]. Löslichkeitskonstanten und Freie Bildungsenthalpien von ZnCO3 und Zn5(OH)6(CO3)2 bei 25°
Authors: Schindler P. , Reinert M. , Gamsjäger H.
Published: December 2004

The solubilities of ZnCO3 and Zn5(OH)6(CO3)2 have been investigated at 25°C in solutions of the constant ionic strength 0,2 M consisting primarily of sodium perchlorate. From experimental data the following values for equilibrium constants and GIBBS free energies of formation are deduced:

A predominance area diagram for the ternary system Zn2+–H2O–CO2(g) including ZnO, ZnCO3, Zn5(OH)6(CO3)2, and Zn2+ is given.
Eine präparative Synthese von Streptozotocin
Authors: Hardegger E. , Meier A. , Stoos A.
Published: December 2004

Durch Umsetzung von D‐Glucosamin mit dem bisher unbekannten N‐Nitroso‐methylcarbamylazid (VII) wurde das Beta‐Zytotoxin Streptozotocin (VIII) synthetisch präparativ zugänglich gemacht.
Über die Stabilitätsbereiche der Bleisalze des 2,4,6‐Trinitroresorcins in wässeriger Lösung
Authors: Durtschi A. , Rauber W. , Aebi F.
Published: December 2004

Das 2,4,6‐Trinitroresorcin (  H2Tric) bildet ausser den bereits bekannten Bleisalzen PbTric · H2O und Pb2(OH)2 Tric noch die Verbindungen Pb5(OH)6Tric2 und Pb13O7(OH)8Tric2. Diese Niederschläge wurden aus Pb(ClO4)2‐Lösungen durch Zugabe von NaOH und Trinitroresorcin erzeugt. Die überstehenden Lösungen waren 0,2 M an NaClO4. Nach zehnmonatiger Versuchsdauer wurde in ihnen – log[Pb]total, – log[Tric]total und – log[H+] bestimmt. Daraus wurden für die Löslichkeitskonstanten

folgende Werte bestimmt:

Bodenkörper
−log*L
Bodenkörper
−log*L

PbTric · H2O
5,35 ± 0,06
Pb5(OH6)Tric2
−1,26 ± 0,15

Pb2(OH)2Tric
−0,40 ± 0,25
Pb13O7(OH)8Tric2
−7,96 ± 0,19

Pb5(OH)6Tric2
−2,36
PbO · Pb(OH)2
−12,33 ± 0,09

Die Werte der linken Spalte sind nur im Bereich – log[H+] ⩽ 8,5, die der rechten nur im Bereich – log[H+] ≥ 11,0 gültig.

Aus diesen Daten wurde das Prädominanzdiagramm mit den Achsen – log[H+], – log[Pb]total und – log[Tric]total gezeichnet. Das Diagramm wird bei höheren pH‐Werten durch das PbO · Pb(OH)2 abgeschlossen.
Zur Herstellung von Reinstantimon durch Gasphasenreaktion
Authors: Gäumann A.
Published: December 2004

The influence of evaporation temperature, reaction temperature, gas flow, and the ratio H2/SbCl3 on the gas phase reaction

Economic production of ultrapure antimony is possible with this gas phase reaction.
Synthese des «Thyrotropin‐releasing» Hormons (TRH) (Schaf) und verwandter Peptide
Authors: Gillessen D. , Lergier W. , Studer R. O. , Felix A. M.
Published: December 2004

The syntheses of seven tripeptide isomers containing L‐histidine, L‐proline and L‐glutamic acid residues, the same as found in the natural thyrotropin‐releasing hormone (TRH), are reported. In addition L‐pyroglutamyl‐L‐histidyl‐L‐proline and its amide as well as Nα‐acetyl‐L‐glutamyl‐L‐histidyl‐L‐proline are described. Whereas eight peptides are inactive and L‐pyroglutamyl‐L‐histidyl‐L‐proline shows a slight TRH activity, L‐pyroglutamyl‐L‐histidyl‐L‐proline‐amide has the full biological activity of the isolated thyrotropin‐releasing hormone and, at the present state of knowledge, seems to be identical with it.
Reaktionen von α‐Chlorcarbonsäurechloriden mit Trialkylaminen
Authors: Giger R. , Allain R. , Rey M. , Dreiding A. S.
Published: December 2004

The condensation of α,α‐dichloropropionyl chloride (IVa) and of trichloroacetyl chloride (IVb) with α‐chloropropionyl chloride (Ia) in the presence of triethylamine led to two acid chloride enol‐esters, both as mixtures of cis‐ and trans‐isomers, namely 1, 2‐dichloropropenyl α,α‐dichloropropionate (Va) and 1, 2‐dichloropropenyl trichloroacetate (Vb).

A mixture of triethylamine and trichloroacetyl chloride produced an oxidation‐reduction reaction to give 48% 1, 2, 2, 2‐tetrachloroethyltrichloroacetate (VIII) and 69% 1‐diethylamino‐4, 4, 4‐trichloro‐1‐butene‐3‐one (IX). Basic hydrolysis of IX led to 43% of glutaconic acid (XIII). Tripropylamine reacted in the same way with trichloroacetyl chloride to yield 1‐dipropylamino‐2‐methyl‐4, 4, 4‐trichloro‐but‐1‐ene‐3‐one (XIX) which was readily hydrolyzed in acid solution to α‐trichloroacetyl‐propionaldehyde (XX).
Isolierunǵ von (‐)‐allo‐Muscarin aus Amanita muscaria. 33. Mitteilung über Inhaltsstoffe von Fliegenpilzen
Authors: Schleusener E. , Eugster C. H.
Published: December 2004

Aus Fliegenpilzen (Amanita muscaria) wurde (–)‐allo‐Muscarin isoliert.
Russula‐Farbstoffe: Erkennung der roten Hauptkomponenten als dimere Pteridinǵlykoside; Trennung von Pterinen durch isoelektrische Fokussierung in einem pH‐Saccharose‐Gradienten. Vorläufige Mitteilung
Authors: Euǵaster C. H. , Frauenfelder E. F. , Koch H.
Published: December 2004

The genus Russula is rich in colourless, yellow and red pteridine derivatives. The main dyestuffs of the pileus of the red species (R. emetica, badia, sardonia, obscura, paludosa) are recognized as glycosides of dimeric pteridine derivatives. The main component is a D‐riboside. It has been named Russupteridin‐sIII. The chromophore is very similar to that of rhodopterine (pterorhodine; I).

Rhodopterine has been cleaved by aqueous ammonia to give xanthopterine and 7‐methyl‐xanthopterine, respectively.

The new technique of isoelectric focusing using a pH and sucrose gradient [7] [8] effectively separated pterines and Russula‐dyestuffs. Preparative separation was achieved by means of a sephadex G25 chromatographic column using pyridine‐water as a eluant.
Photochemische Darstellung von Hexaalkylborazol‐und Aromaten‐chromtricarbonylen
Authors: Deckelmann K. , Werner H.
Published: December 2004

The half‐sandwich type complexes LCr(CO)3 (L=(C2H5)3B3N3(CH3)3, (CH3)3B3N3(C2H5)3, C6H6, sym‐C6H3(CH3)3) have been prepared by photochemical reaction of Cr(CO)6 with the appropriate ligand L at highly reduced pressure. This new method is of particular advantage for the synthesis of the hexaalkylborazole complexes.
Utilisation d'ylides du phosphore non stabilisés en chimie des sucres. IV. Nouveaux exemples de sucres méthylthiovinyliques terminaux. Communication préliminaire
Authors: Tronchet J. M. J. , Le‐Hong N. , Perret F.
Published: December 2004

The previously described one‐carbon chain extension of aldehydo‐sugars with methylthiomethylene‐triphenylphosphorane has been successfully applied to an anhydro‐aldehydo‐sugar and two w‐aldehydo‐sugars. Some spectroscopic properties of the so obtained methylthiovinylic sugars are given.
Über Pterinchemie. 28. Mitteilung. Hydroxylierung von Phenylalanin zu Tyrosin mittels Tetrahydropterin unter physiologischen Bedingungen
Authors: Viscontini M. , Mattern G.
Published: December 2004

Es werden die Versuche und Ergebnisse beschrieben, die zur Entwicklung der Theorie eines Radikalmechanismus für die Hydroxylierung des Phenylalanins mittels Tetrahydropterin unter physiologischen Bedingungen beigetragen haben.
Untersuchungen über das Verhalten organischer Mischphasen 9. Mitteilung Vergleich der binären Systeme Tetrahydrofuran mit Wasser, Methanol und Cyclohexan, Diäthyläther mit Wasser, Methanol und Cyclohexan und Tetrahydrofuran‐Diäthyläther
Authors: Arm H.
Published: December 2004

Activities and mixing functions of the following binary systems at 25° C are discussed: 1. mixtures of tetrahydrofuran with water, methanol, and cyclohexane; 2. mixtures of diethyl ether with water, methanol, and cyclohexane, and 3. mixtures of tetrahydrofuran with diethyl ether. Comparison with similar systems shows that in systems containing methanol, the strongest interactions are formation and breaking of hydrogen bonds between alcohol molecules; interactions between methanol and ether molecules play a minor rǒle. Systems containing water exhibit two main kinds of interaction: formation and breaking of hydrogen bonds between water molecules, and formation of hydrogen bonds between water and ether molecules. Deviations from ideality are larger for diethyl ether than for tetrahydrofuran in water and methanol, and smaller in cyclohexane.
Synthese von terpenartigen bicyclischen Systemen über die Cycloaddition von Dimethylketen an Methylcyclopentadien
Authors: Huber Ulrich A. , Dreiding André S.
Published: December 2004

The structure of the cyclo‐addition products of ketenes (2) and methylcyclopentadiene could not be predicted, since this ketenophile exists as a rapidly equilibrating 45:54:1 mixture of the 1‐ (4), 2‐ (5) and 5‐methyl (6) isomers. We studied this reaction using dimethylketene (2a) with a view to monoterpenoid synthesis. Only two (A and B) of the many possible cyclo‐adducts were formed in good yield. Using three methods to generate dimethylketene, the ratios of A:B were 90:6, 77:16 and 55:31 respectively.

The structures of A and B were proved without making use of the known ketene cyclo‐addition rules: Of the many possibilities, all but 7, 8, 9 and 10 were excluded by the CO and CCCH3 IR.‐bands and NMR. signals. Structure 7 (filifolone) was rejected by the difference of its NMR. spectrum from those of both A and B, leaving only 8, 9 and 10.

For A, structures 9 and 10 were eliminated by two chemical approaches: (1) Peracetic acid oxidation of a mixture rich in A resulted in a combination of Baeyer‐Villiger reaction, epoxidation, and epoxide‐ketone rearrangement affording a C10‐keto‐lactone 14, which was cleaved by alkali to acetone and a C7‐keto‐acid 18. (2) Another peracetic acid treatment produced a keto‐epoxide 11, which was converted to a diol 22 and then to a diketo‐aldehyde 23 with an NMR. doublet for the aldehyde proton.

Of the two structures (9 and 10) left for B, the latter was excluded by the NMR. spectrum of keto‐epoxide 15 isolated from the peracid treatment of a mixture rich in B: A decoupling experiment with 15 showed that the ‐CH2‐ was placed next to the α‐carbon of the carbonyl function.

Thus the major cyclo‐adduct of dimethylketene and methylcyclopentadiene is 8, and the minor product is 9. This result demonstrates further ketene cyclo‐addition specificities on top of the ones expressed by the three known rules. The different ratios of 8 : 9 are considered to be due to varyingly effective competition between the preliminary interconversion of the methylcyclopentadienes and their cyclo‐addition of dimethylkctene.

A number of other oxidation and reduction products of 8 are described. One of them proved that C7 had migrated in the Baeyer‐Villiger reaction.

A partial separation of the enantiomers of the major cycloadduct 8 was achieved. By the use of 0.5 equivalent of three chiral primary amines (31, 32, and 33) to form a Schiff base, the excess ketone 8 was in each case distilled off in a chirally enriched form with positive optical rotation. The derived 2.3‐dihydroketone 36 was shown to have a positive Cotton effect and, by an application of the octant rule, to have the (1R,5S) chirality orientation.
Contribution à la connaissance des o‐menthols et des o‐menthones (carquéjanols et carquéjanones). 2e communication
Authors: Ferretti‐Alloise Maria‐Giulia , Jacot‐Guillarmod André , Naves Yves‐René
Published: December 2004

(+)‐Carquejanone and (‐)‐isocarquejanone have been described by their IR. spectra and configurationally studied by optical rotatory dispersion and circular dichroism (Cotton effect). The application of the octant rule confirms the configurations previously assigned by Thomas.
The Pyrolysis of Fur‐2‐ylmethyl Vinyl Ethers
Authors: Thomas Alan F.
Published: December 2004

The pyrolysis of fur‐2‐ylmethyl vinyl ether and its next highest homologue, the propenyl ether, is described. Products from two reaction mechanisms are observed namely a 3‐substituted 2‐methylfuran from an electrocyclic mechanism, and 1,2‐di‐(fur‐2‐yl)‐ethane and furylpropanal from a biradical mechanism.
Die nucleofuge Aktivität von Substituenten am Brückenkopf von Bicyclo[2.2.2]octan und Chinuclidin Das kOTs/kBr‐Verhältnis als mechanistisches Kriterium. Fragmentierungsreaktionen, 24. Mitteilung
Authors: Grob C. A. , Kostka K. , Kuhnen F.
Published: December 2004

The rate ratios kOTs/kBr of the bridgehead tosylate and bromide of bicyclo [2.2.2]‐octane and quinuclidine, respectively, have been determined in 80 vol.‐% ethanol. The high ratio for the bicyclo [2.2.2] octane derivatives (3,3 · 103 at 25°) indicates a highly ionic transition state. Since nucleophilic assistance to ionisation by solvent is precluded in this system a ratio of 103 or greater is typical for the «limiting» SN1 mechanism. Lower kOTs/kBr ratios therefore reflect increasing nucleophilic participation in the transition state of substitution and elimination reactions.

The high kOTs/kBr ratio for 4‐substituted quinuclidines, namely 1,6 · 103 at 25°, indicates the absence of anchimeric nitrogen participation in the transition state of this synchronous fragmentation. The rates of the 4‐haloquinuclidines follow the normal order of nucleofugal activity for halides in solvolysis reactions.
Etude théorique et possibilités d'application de la méthode de «variations continues» [1] aux complexes très dissociés
Authors: Marcantonatos M. , Buffle R. , Monnier D.
Published: December 2004

A theoretical study of the possibilities of applicability to very unstable complexes of the «continuous variation» principle shows that the general equation of a theoretical Job's curve can be reduced, for limiting values of x and 1 − x (x being the ligand's mole fraction), to expressions permitting the determination of the number «m» of the central groupes, the number «n» of the ligands, and the stability constants of highly dissociated complexes. Theoretical and practical limitations are discussed.
C‐Glycosides II. Synthèse d'un analogue de la pyrazomycine. Communication préliminaire
Authors: Tronchet J. M. J. , Perret Mlle F.
Published: December 2004

A synthesis of 3‐β‐D‐erythro‐furanosyl‐1‐p‐nitrophenyl‐pyrazole is described.
Der geschwindigkeitsbestimmende Schritt bei der Decarboxy‐lierung von 2,4‐Dihydroxybenzoesäure in mässig konzentrierter wässeriger Salzsäure
Authors: Willi A. V. , Cho M. H. , Won C. M.
Published: December 2004

The decarboxylation kinetics of 2,4‐dihydroxybenzoic acid have been studied in 0.1–8 N aqueous HCl at 50°. At low HCl concentrations, the observed first order rate constant, k, increases with increasing acidity of the solution. In solutions with 3.5–6 N HCl, k remains constant.

The D2O solvent isotope effect decreases from kH2O/kD2O = 2.0 in 1N HCl to 1.3 in 5 N HCl, and it remains unchanged at 1.3 if the HCl concentration is increased further to 8 N.

It is concluded that an increase of the acidity of the solution causes a change of the rate determining step from slow proton transfer to rate limiting CC bond cleavage.
Totalsynthese des Antibioticums Anisomycin
Authors: Felner I. , Schenker K.
Published: December 2004

The synthesis of the antibiotic anisomycin (1) is described. In the key step 3, 4‐dimethoxy‐thiopyrrolidone (16), prepared from diethyl L‐( + )‐tartarate (4) was converted to the thioiminoester 18, which upon treatment with trimethylphosphite yielded the benzylidene derivative 19. Cleavage of the ester group of 19 and hydrogenation of the decarboxylation product gave the two isomers 21 and 22. 22 was converted into desacetylanisomycin (3) and anisomycin (1).
Über Pterinchemie. 31. Mitteilung [1]. Hydroxylierung von Tryptophan mittels Tetrahydropterin unter physiologischen Bedingungen
Authors: Viscontini M. , Mattern G.
Published: December 2004

Die experimentelle Arbeit der 21., vorläufigen Mitteilung [3] wird beschrieben. Dort wurde gezeigt, dass Tryptophan an der Luft in wässeriger Lösung mittels Tetrahydropterin und Eisen (II) als Sauerstoffaktivator unter physiologischen Bedingungen hydroxyliert wird, wobei 5‐Hydroxytryptophan, Melanine, Kynurenin, 3‐Hydroxykynurenin, Xanthommatin u. a. isoliert werden können.
Synthèse de quelques dérivés de l'amino‐3‐didésoxy‐3, 5‐D‐lyxose Communication préliminaire
Authors: Tronchet J. M. J. , Graf R.
Published: December 2004

LAH reduction of 3, 5‐dideoxy‐1, 2‐O‐isopropylidene‐β‐D‐threo‐pentofuranose‐3‐ulose oxime leads with a high stereoselectivity to 3‐amino‐3, 5‐dideoxy‐1, 2‐O‐isopropylidene‐β‐D‐lyxofuranose. Some derivatives of the latter compound are described.
Synthèse d'analogues partiellement saturés de l'amitriptyline à partir d'ortho‐tolunitriles. 2e Communication sur les antidépresseurs et les neuroleptiques tricycliques [1]
Authors: Dostert P. , Kyburz E.
Published: December 2004

Substituted o‐tolunitriles are alkylated with 1‐bromomethyl‐cyclohexene. Saponification yields substituted o‐[2‐(1‐cyclohexen‐1‐yl)‐ethyl]‐benzoic acids, which are cyclised to 1,2,3,4,10,11‐hexahydro‐5H‐dibenzo[a,d]cyclohepten‐5‐ones. Reaction of the latter with (3‐dimethylamino‐propyl)‐magnesium chloride yields, after dehydration, hexahydro derivatives of the known antidepressant amitriptyline. The position of the double bonds remains uncertain.
Über die Synthese von O‐Glycyl‐N‐(2, 3, 4‐trihydroxybenzyl)‐hydroxylamin‐dihydrobromid
Authors: Hegedüs B. , Krassó A. F.
Published: December 2004

The synthesis of O‐glycyl‐N‐(2, 3, 4‐trihydroxybenzyl)‐hydroxylamine dihydrobromide (3) starting from carbobenzoxy‐glycine and tritylhydroxylamine is described. In contrast to the corresponding isosteric hydrazine derivative 1, 3 is no decarboxylase inhibitor.
β‐Eliminativer Abbau bei 4‐0‐substituierten Hexopyranosiduronat‐Derivaten
Authors: Kiss J. , Burkhardt F.
Published: December 2004

Two types of endocyclic enol‐acetal forming β‐elimination were investigated on synthetic model compounds. In both types the 4‐O‐methanesulfonyl residue was chosen as leaving group. The a,e‐β‐elimination was proved on 2,3‐benzyl ether protected D‐glucopyranosiduronate derivatives I, and the a, a‐β‐elimination on the analogous substituted D‐galactopyranosiduronates XVII. Using a small excess of KOH in methanol at 25°, a quick elimination of a molecule of methanesulfonic acid was observed, and as reaction product the 4,5‐unsaturated 4‐deoxyhexopyranosiduronate derivative II was obtained. Only an unimportant stereoselectivity was found between the a,e‐ and a,a‐mesylate β‐eliminations.

The 4,5‐unsaturated 4‐deoxyhexopyranosiduronates show a strong UV. maximum at 238 nm, and Cotton effects in the ORD. spectra. This stable ring system with an endocyclic enol‐acetal linkage is present in a half‐chair (H) conformation.

The structure of the unsaturated deoxyhexopyranosiduronate obtained was established by structure‐ and stereo‐correlation with a 2‐deoxy‐L‐xylose derivative, showing that a ring contraction during the β‐elimination does not occur.
L'isomérie géométrique d'amidines mono‐substituées de l'acide benzothiazole‐carboxylique‐2. Isomères anti à carboxyle normal, isoméres syn à carboxyle énolisé
Authors: Baudet Pierre , Rao Dinesh
Published: December 2004

The condensation of methyl benzothiazole‐2‐iminicarboxylate with α‐amino‐acetic esters gives rise to amidines possessing only one (I) of the two possible tautomeric structures. magnified image Both syn and anti isomers have been characterized of the single tautomer. This is the first demonstration of geometrical isomerism around the imine group in amidines.

The carboxylic esters and the free acids of the syn fro exist exclusively as the enol, whereas the anti derivatives prefer the carboxyl structure. The existence of these isomers has been confirmed by their IR., UV., and NMR. spectra as well as by the inversion of their configuration and the formation of cyclic derivatives.
Aminodiacylhydrazin‐Umlaǵerungǵ. 5. Mitteilung. Über die Hydrazoessigsäure
Authors: Gisin B. , Brenner M.
Published: December 2004

Hydrazoacetic acid (7) and a variety of derivatives by alteration of the hydrazo or the carboxyl groups were synthesized. 7 forms complexes with metalions. Under certain conditions N‐acety‐N′‐glycyl‐hydrazoacetic acid (17) undergoes rearrangement into N‐(N‐acetyl‐glycyl)‐hydrazoacetic acid (18).
Sur l'acylation des méthylfluorènes IV. [1] Benzoylation du méthyl‐4‐fluorène
Authors: Chardonnens Louis , Dousse Roland , Horwath Ernö
Published: December 2004

Benzoylation of 4‐methylfluorene according to Friedel‐Crafts in carbon disulfide with aluminium chloride yielded two benzoyl derivatives: 5‐methyl‐2‐benzoyl‐fluorene (II) (major product), and 4‐methyl‐2‐benzoyl‐fluorene (III). By oxidation II and III gave the corresponding 9‐oxo‐derivatives, the structure of the last compounds being proved by an independent way.
Die photochemische Anlagerung von Nitrosaminen an Inden
Authors: Wyss E. G. , Schindler O.
Published: December 2004

The 1‐oximino‐2‐amino‐indane derivatives IV‐a and IV‐b are formed by the photoaddition reaction of N‐nitrosomorpholine and N‐nitrosopiperidine with indene. Reduction with LiAlH4 led to the corresponding amines V‐a and V‐b supposed to have trans‐configuration. Substitution of secondary bases to the chlorine atom in the bis‐nitrosochloride II produced compounds of type III which are isomers of IV. The constitution of II was confirmed by conversion to 2‐amino‐indane (VI).
Contribution à l'étude du système quaternaire K+NH4+CrOSOH2O: II. L'isotherme de 25°C
Authors: Flatt R. , Brunisholz G. , Merbach A.
Published: December 2004

The study at 25°C of the system K+NHCrOSOH2O has shown experimentally the existence of a new type of quaternary system of solubility with two cations and two anions. The solubility diagramm is caracterized by the presence of two adjacent ternary limiting systems with a miscibility gap, three univariant lines (one of them being evanescent), one invariant point, three binary and one ternary miscibility gaps.
Über die spektrale Sensibilisierung von Zinkoxid: I. Sorptionsverhalten von o,o′‐Dihydroxyazofarbstoffen
Authors: Brändli R. , Rys P. , Zollinger H. , Oswald H. R. , Schweizer F.
Published: December 2004

o,o′‐Dihydroxyazo compounds are spectral sensitizers for the photosemiconductor properties of zinc oxide. It is shown that 1‐(2‐hydroxyphenylazo‐)‐2‐naphthol (II) forms a 1:1 Zn complex on the surface of ZnO particles if adsorbed from toluene solution. With most samples of ZnO a Langmuir type adsorption isotherm is obtained. The concentration of the dye at saturation relative to the BET surface of the ZnO particles correponds to a slightly oblique edge‐on arrangement of the dye molecules on the surfaces.

In the case of ZnO pretreated with propionic acid and having taken up dye in excess of a monolayer, it can be shown by electron microscopy that tail‐like complexes (zinc: dye ratio = 1:1) are formed, and that these complexes contain zinc which was originally on the particle surfaces.
Die Cardenolide von Anodendron paniculatum (ROXB.) A. DC. Glykoside und Aglykone, 326. Mitteilung.
Authors: Polonia J. , Jäger Herb. , v. Euw J. , Reichstein T.
Published: December 2004

The wood of Anodendron paniculatum contains a large number of cardenolides; 14 of such compounds could be spottet in PC. and TLC. with Kedde reagent. Five of these (A, E 1, E 2, F, and G) could be isolated in crystalline form and two other ones (B 1 and B 2) as an amorphous mixture. A crystalline aromatic ketone (compound α) was obtained as by‐product. The isolated cardenolides, named as anodendrosides A‐G, were found to be glycosides containing unusual sugars. According to UV. and IR. spectra the genin portion in anodendroside E 1 (probably also in F and B 2) contains a cardenolide structure with saturated ring D and normal butenolide side‐chain, while the anodendrosides A, E 2 and G (probably also B 1) contain an additional double bond at C‐16. The four compounds for which IR. spectra could be taken (A, E 1, E 2, and G) possess a keto group.
Eine Abfangmethode zum Nachweis kurzlebiger Carbenium‐Ionen in stark sauren Reaktionsmedien
Authors: Bosshard H. , Baumann M. E. , Schetty G.
Published: December 2004

In a new approach, unstable carbenium ions produced in strong protic media could be trapped by thioethers yielding sulfonium compounds. The method has successfully been applied to the rearrangement reactions of sec‐butyl alcohol and pinacol, where carbenium ions could be trapped before their rearrangement.

In the case of the pinacol‐pinacon rearrangement the carbenium ion 13 has already been discussed but for the first time its existence is proved.

Since compound 16 has been found, a new mechanism for the pinacol‐pinacon rearrangement is postulated starting with diprotonated pinacol.
Photoisomerisierung von o‐Di‐isobutenylbenzol
Authors: Ulrich L. , Hansen H.‐J. , Schmid H.
Published: December 2004

o‐Di‐isobutenyl‐benzene (4) on irradiation in hexane with a low‐pressure mercury lamp gives 4 photoproducts in an overall yield of 24%. Three of these products were identified as 4, 4, 6, 6‐tetramethyl‐benzobicyclo [3.1.0] hex‐2‐ene (5, main product, 14%), 1.1‐dimethyl‐2‐isopropenyl‐indane (6, 8%) and 1‐isopropenyl‐2, 2‐dimethyl‐indane (10, 2%). 6 is also formed by irradiation of 5 in hexane.
Transformation, par 1′anhydride acètique, d'aldèhydes à caractére èlectrophile prononcè; catalyse par des pyridines. 1. Acyloïnes et hydrates di‐o‐acètylès d'aldèhydes
Authors: Baudet P. , Otten Cl.
Published: December 2004

2‐Benzothiazole‐carbaldehyde is transformed into di‐O‐acetyl‐enol‐(benzothiazolecarboxyl‐2)‐oin in the presence of acetic anhydride and of pyridine as catalyst. Without pyridine or with 2,6‐lutidine no reaction occurs. A mechanism of this reaction is proposed. No reaction was observed in the case of benzaldehyde.

Choral reacts with acetic anhydride in the presence of pyridine as well as of 2,6‐lutidine as catalyst to give 1,1‐diacetoxy‐2,2,2‐trichloro‐ethane. A mechanism is proposed, in which in an intermediate state the acetate ion (and not pyridine, for steric reasons) attacks the carbon of the carbonyl function of the conjugate acid with the acetylium cation to yield 1,1‐diacetoxy‐2,2,2‐trichloro‐ethane.

These two reactions occur only with aldehydes whose carbonyl is very electrophilic, and seem to be a possible way to point out the presence of an acylium cation in pyridine medium.
Über die Stereochemie der Hydrogenolyse von N‐Benzyl‐Bindungen I. Die Hydrogenolyse von Derivaten der 2‐Amino‐2‐phenyl‐propionsäure.
Authors: Dahn H. , Garbarino J. A. , O'Murchu C.
Published: December 2004

The stereochemistry of the hydrogenolysis of benzyl‐N bonds was studied using S(+)‐2‐dimethylamino‐2‐phenyl‐propionic acid (I) and its derivatives, and R(−)‐2‐anilino‐2‐phenyl‐propionic acid (II). The configuration of I was confirmed, that of II established by ORD. measurements, after transformation of the phenyl into cyclohexyl groups. On a palladium catalyst the hydrogenolysis of I, its methyl and ethyl esters and its amide proceeded with 72 to 99% inversion of configuration, that of II with at least 66% inversion. The ester of the quaternary ammonium derivative of I gave as much inversion as retention (= racemisation).
Thermodynamique des mélanges liquides binaires. Chaleurs de mélange des cycloalcanes
Authors: d'Almeida M. Dias , Fernandez‐Garcia J. G. , Boissonnas Ch. G.
Published: December 2004

Heats of mixing were measured between 10° and 80°C for all binary systems formed with cycloalcanes CnH2n, n = 5, 6, 7, 8.
Applications of “Artificial Intelligence” for Chemical Inference, VI. Approach to a General Method of Interpreting Low Resolution Mass Spectra with a Computer
Authors: Buchs Armand , Delfino Allan B. , Duffield A. M. , Djerassi Carl , Buchanan B. G. , Feigenbaum E. A. , Lederberg J.
Published: December 2004

Le programme connu sous le nom de «Heuristic DENDRAL» est maintenant capable d'interpréter d'une manière absolument automatique les spectres de masse à basse résolution de n'importe quel composé de formule élémentaire CnH2n+vX (X = 0, S ou N, v = valence de X). La possibilité de faire usage de spectres de RMN. pour faciliter l'interprétation a été retenue. Il n'est plus nécessaire de fournir au programme la formule élémentaire du composé dont on veut déterminer la structure. Les données théoriques concernant la spectrométrie de masse et la résonance magnétique nucléaire sont créées par le programme lui‐même. A aucun moment le chimiste n'a besoin de fournir d'autres données que le spectre de masse et, s'il le désire, le spectre de RMN. L'efficacité du programme a été mise à l'épreuve avec 210 spectres de masse. La structure correcte apparaît toujours dans la réponse. Les résultats reportés dans les tableaux 2, 3 et 4 montrent que le nombre d'isomères qui sont compatibles avec la réponse donnée par le programme représente une trés importante réduction du nombre total d'isomères qui sont a priori des candidats possibles.
Dünnschichtchromatographie anorganischer Ionen. 11. Mitteilung. Trennung verschiedener Oxydationsstufen von Vanadium
Authors: Seiler H.
Published: December 2004

The separation of VIII, VIV and VV by thin‐layer chromatography is described.
Stoffwechselprodukte von Mikroorganismen. 84. Mitteilung [1]. Synthese des 5‐Chlor‐6‐methyl‐salicylsäure‐methyläthers, eines Abbauproduktes des Chlorothricins
Authors: Muntwyler R. , Widmer J. , Keller‐Schierlein W.
Published: December 2004

5‐Chloro‐6‐methyl‐salicylic acid methyl ether was synthesized starting from 2‐nitro‐5‐hydroxy‐toluene. It was identical with a degradation product of the antibiotic chlorothricin.
Die Alkaloide aus Hedranthera barteri (Hook. f.) Pichon. 139. Mitteilung über Alkaloide
Authors: Agwada V. , Patel M. B. , Hesse M. , Schmid H.
Published: December 2004

From the root bark of the apocynacea Hedranthera barteri (Hook. f.) Pichon were isolated the known indole alkaloids vobtusine (1), voacamine (2), callichiline (3), voacangine (4) and conoflorine (5), as well as the unknown plant bases amataine, goziline and owerreine, and also beninine and 1, 2‐dehydrobeninine. The structures of the two last mentioned alkaloids were shown in an earlier publication to be 6 and 7, respectively. Amataine, goziline and owerreine are bis‐indole alkaloids, which on the basis of their chemical and spectroscopic (especially mass spectroscopic) properties have been assigned the structures 8, 9 and 10, respectively.
Die Struktur von Panepoxydon und verwandten Pilzmetaboliten
Authors: Kis Z. , Closse A. , Sigg H. P. , Hruban L. , Snatzke G.
Published: December 2004

The structure of panepoxydone (1) and some related products, produced by two species of Panus (basidiomycetes), are proposed on the basis of chemical transformations and physical measurements.

The absolute configurations of the main products are deduced by the interpretation of CD. studies and compared with those of the structurally related compounds epoxydone (10), terreic acid (11) and terremutin (12).
Über die 1,2‐Verschiebung von Carbonestergruppen bei der Benzilsäureumlagerung von α,β‐Dioxobuttersäure‐estern. 25. Mitteilung über Reduktone und Tricarbonylverbindungen [1]
Authors: Dahn H. , Gowal Heike , Schlunke H.‐P.
Published: December 2004

In the benzilic acid type rearrangement of t‐butyl α,β‐dioxobutyrate (VII) the intact t‐butoxycarbonyl group is shifted to the β‐carbonyl carbon atom.
O‐Protonation of α‐Diazoketones in Super‐strong Acids
Authors: Wentrup C. , Dahn H.
Published: December 2004

Primary diazoketones, RCOCHN2, are O‐protonated in HFSbF5SO2 or FSO3HSbF5SO2 at −60°, as observed by NMR. The OH‐proton resonates at 9.3–9.6 δ and is coupled with HC 1 (J = 1–2.5 Hz). Secondary diazoketones, RCOC(N2)R, when protonated, give an OH‐singlet at 8.85 δ. The assignments are corroborated by use of deuterated diazoketones, RCOCDN2, or deuterated acid, FSO3D. Primary diazoketones react with FSO3H at −60° to −15°, giving products assigned the fluorosulfate structure, RCOCH2OSO2F; they do not exchange HC 1 with solvent before or during decomposition. Intermediate C‐protonated diazonium ions and α‐oxo‐carbonium ions (vinyl carbonium ions) have not been identified. 3‐Diazo‐4‐methyl‐2‐pentanone (VIII) reacts with FSO3H at −15°, eliminating N2 and giving protonated mesityl oxide by a strictly intramolecular hydride shift.
Eine Synthese O,O‐di‐ und N‐mono‐acylierter L‐Cyclodopaderivate
Authors: Wölcke U. , Kaiser A. , Koch W. , Scheer M.
Published: December 2004

Am Beispiel der Synthese von O,O‐Diacetyl‐L‐cyclodopa‐methylester (12) wird eine allgemein anwendbare Methode zur selektiven Acylierung der phenolischen Hydroxylgruppen oder des Indolin‐Stickstoffs am Cyclodopa (8) beschrieben. Die Verwendung von L‐DOPA (5) als Ausgangsmaterial für die Cyclisierung erlaubt die Darstellung grösserer Mengen solcher Derivate.
Modelle für Kopplungsmechanismus und Träger‐induzierten Alkaliionentransport in Mitochondrienmembranen
Authors: Wipf H.‐K. , Simon W.
Published: December 2004

Energetic coupling of oxidative phosphorylation in mitochondria is discussed in the light of recent findings concerning mediation of alkali cation transport by antibiotics: Decoupling by cation‐specific antibiotics of the valinomycin group, as well as by classical decoupling agents (e.g. 2,4‐dinitrophenol), can easily be interpreted on the basis of their known molecular properties if Mitchell's chemi‐osmotic theory is accepted. «Ion pump» mechanisms, as proposed by several authors, require additional assumptions that do not seem justified.
Die Kristallstruktur von 2,4‐Diamino‐5‐(3,4,5‐trimethoxybenzyl)‐pyrimidin‐1‐oxid‐dihydrat. (Ein Metabolit von Trimethoprim)
Authors: Oberhänsli W. E.
Published: December 2004

The crystal structure of the title compound has been determined by threedimensional X‐ray diffraction methods. The crystals belong to the space group P1 with cell constants

a = 7.851 Å
b = 10.703 Å
c = 10.399 Å

α = 100.06°
β = 97.38°
γ = 75.77°

The structure has been refined to an R‐value of 4.0%.

The geometry of the molecule and the hydrogen bonding in the crystal are discussed.
Synthèse d'analogues partiellement saturés des neuroleptiques tricycliques clothiapine et octoclothépine. 3me Communication sur les antidépresseurs et les neuroleptiques tricycliques [1]
Authors: Dostert P. , Kyburz E.
Published: December 2004

In order to check if the pharmacological activity is retained when the non‐substituted aromatic ring of the neuroleptics clothiapine (I) and octoclothepine (II) is saturated, we have prepared the trans‐hexahydro‐clothiapine XXIV and one of the two possible diastereoisomers each of cis and trans hexahydro‐octoclothepine XL and XLI.
Terpen‐Verbindungen als Arzneimittel, IX. Die vier stereoisomeren Geranylester der Farnesylessigsäure
Authors: Pala G. , Mantegani A. , Bruzzese T. , Sekules G.
Published: December 2004

The preparation and characterization of the four stereoisomeric trans‐geranyl farnesylacetates I–IV are described. Their structure and configuration were identified by mode of formation, elemental analyses, IR. spectra, and particularly by PMR. spectra.
Stabilité des carboxylates de terres rares, II. Bis‐hydroxyméthyl‐2,2‐propionates
Authors: Roulet R. , Vu Duc T.
Published: December 2004

The stability constants of 2, 2‐bis‐hydroxymethyl‐propionates of rare earths have been determined at ionic strength 0,100 (NaClO4) at 25.0°C by a potentiometric method. The ligand forms 1 : 1 and 1 : 2 complexes with all the rare earths and weak 1 : 3 complexes with light rare earths only. In these last complexes, it binds in a unidentate way. The dissociation constant of the acid has also been measured.
Azidiniumsalze. 7. Mitteilung [1]. Synthese von 1‐Äthyl‐2‐azido‐6‐X‐chinolinium‐fluoroboraten
Authors: Balli H. , Schelz D.
Published: December 2004

6‐X‐Quinolines (X = CH3, C6H5, CO2C2H5, Cl, Br) are successively transformed into 1‐methyl‐6‐X‐carbostyrils, 2‐chloro‐6‐X‐quinolines and 1‐ethyl‐2‐chloro‐6‐X‐quinolinium‐tetrafluoroborates; the latter are transformed into the title compounds by reaction with sodium azide in methanol. 2‐Chloro‐6‐acetamido‐quinoline is alkylated at two positions: at the nitrogen atom of the heterocyclic ring and obviously at the oxygen atom of the 6‐substituent; with sodium azide in methanol the product of alkylation yields 1‐ethyl‐2‐azido‐6‐amino‐quinolinium‐tetrafluoroborate. 1‐Ethyl‐2‐azido‐6‐nitro‐quinolinium‐tetrafluoroborate is obtained by treating 1‐ethyl‐2‐hydrazino‐6‐nitro‐quinolinium‐chloride with sodium tetrafluoroborate and sodium nitrite in diluted hydrochloric acid.
Azidiniumsalze. 8. Mitteilung [1]. Darstellung und Eigenschaften substituierter Chinolintriaza‐trimethincyanine
Authors: Schelz D. , Balli H.
Published: December 2004

The synthesis of triaza‐trimethin‐cyanine‐tetrafluoroborates from 1‐ethyl‐2‐azido‐6‐X‐quinolinium‐tetrafluoroborates and sodium azide is described. The visible spectra and the properties of the dyes are discussed.
Reduction of 6‐Trichloromethyl‐2‐pyrones with Metal Hydrides and with Zinc
Authors: Dunkelblum E. , Rey M. , Dreiding André S.
Published: December 2004

Die vor kurzem beschriebenen 6‐Trichlormethyl‐2‐pyrone wurden mit Zink und mit komplexen Metallhydriden reduziert. 6‐Trichlormethylpyron (15) und drei an C4 verschieden alkylierte Derivate (5, 16 und 17) ergaben mit Zink in Eisessig die entsprechenden 6‐Methyl‐2‐pyrone 18, 1, 19 und 20. Im Falle des 6‐Trichlormethyl‐4‐(4′‐methyl‐pent‐3′‐en‐yl)‐2‐pyrans (17) bildete sich auch 3,8,8‐Trimethyl‐5,6,7,8‐tetrahydro‐isocumarin (21).

Die komplexen Metallhydrid‐Reduktionen wurden am Beispiel des 6‐Trichlormethyl‐4‐methyl‐2‐pyron (5) untersucht. Mit Natriumborhydrid in Äthanol entstanden 6‐Dichlormethyl‐4‐methyl‐2‐pyron (6, 14%) und 6,6,6‐Trichlor‐3‐methyl‐hex‐3‐en‐1, 5‐diol (7, 37%). Mit Lithiumaluminiumhydrid in Tetrahydrofuran erhielt man 6‐Chlor‐ (10, 47%) und 6,6‐Dichlor‐3‐methyl‐hexa‐3,5‐dien‐1‐ol (9, 19%). Für diese Hydridreduktionen wird ein Mechanismus vorgeschlagen, welcher mit den Produkten der Lithiumaluminiumdeuterid‐Reduktion nicht in Widerspruch steht.