bluuebunny/crossref_metadata_2025 huggingface dataset:
Studien in der Lumiflavin‐Reihe VI. Alkylierungs‐ und Desalkylierungs‐Reaktionen an (Iso)alloxazinen; 1,3,10‐Trimethylflavosemichinone
Authors: Hemmerich P. , Prijs B. , Erlenmeyer H.
Published: December 2004

The complex alkylation reactions of leucoflavin derivatives are shown to give O‐substituted products of a new type rather than N‐substituted ones. Characteristic differences in the chemical behaviour of (iso)alloxazines and of their leuco‐compounds are outlined. Stabilization and decomposition of flavosemiquinones have been further studied. It is shown, that flavin catabolism (N‐10‐dealkylation) occurs in the semiquinonoid state at room temperature, and is neither confined to hydroxyalkylflavins, nor to specific catalysis by light. Based upon these and recent findings of other authors, a new mechanism of metal‐catalysed flavin catabolism is proposed. 1,3,10‐Trimethyl‐leucoflavin was prepared and found to give a stabilized monomeric semiquinone on oxidation.
Etude des composés d'addition des acides de LEWIS X. Spectres infrarouges des composés formés par les chlorures d'acide avec le tétrachlorure de titane
Authors: Cassimatis D. , Gagnaux P. , Susz B. P.
Published: December 2004

Les auteurs ont préparé les composés d′addition des chlorures de benzoyle, de mésitoyle et d'acétyle avec TiCl4 et étudié leurs spectres d'absorption infrarouge, qui prouvent des différences de structure entre ces corps. L′étude rétigraphique du chlorotitanate de mésitoylium a confirmé l'existence à l'état solide d'une espèce chimique définie.
Eine einfache Methode zur Herstellung von in Ring A ungesättigten 9, 11‐Dehydro‐16α‐methyl‐steroiden. Über Steroide, 162. Mitteilung
Authors: Wieland P. , Heusler K. , Wettstein A.
Published: December 2004

A study of the reactions involved in the preparation of 16α‐methyl‐17α‐hydroxy‐21‐acetoxy‐Δ1;4;9,11‐pregnatriene‐3, 20‐dione (V) from the corresponding 11α‐sulfonyloxy‐2,4‐dibromo‐allopregnane‐3,20‐diones led to a process in which all three substituents in 2‐, 4‐ and 11α‐positions are eliminated simultaneously. 2‐Halogen‐Δ4;9,11‐pregnadiene‐3,20‐diones were formed as by‐products which were reduced to the halogen‐free dienes.
Syntheseversuche in der Emetin‐Reihe. 7. Mitteilung. Abbau und Synthese substituierter 2‐Oxo‐hydrobenzo[a]chinolizine
Authors: Brossi A. , Chopard‐dit‐Jean L. H. , Würsch J. , Schnider O.
Published: December 2004

The course of the HOFMANN degradation in the 2‐oxo‐3‐alkyl‐9,10‐dimethoxy‐1,2,3,4,6,7‐hexahydro‐11bH‐benzo[a]quinolizine series has been elucidated and the constitution of the degradation products established. They represent 1,2,3,4‐tetrahydroisoquinoline derivatives obtained by ring opening between the nitrogen atom and the carbon atom 4. In addition, a new synthesis of substituted 2‐oxo‐9,10‐dimethoxy‐1,2,3,4,6,7‐hexahydro‐11bH‐benzo[a]quinolizines is described.
Die Synthese von Olivacin, Dihydro‐olivacin, Tetrahydro‐olivacin N‐Methyl‐tetrahydro‐olivacin, und die Konstitution von u‐Alkaloid D. Aspidosperma‐Alkaloide, 7. Mitteilung
Authors: Schmutz J. , Wittwer H.
Published: December 2004

Es wird die Synthese des 4,11‐Dimethyl‐10H‐pyrido(4,3‐b)carbazols (XXII) beschrieben, welches mit dem natürlichen Alkaloid Olivacin identisch ist. Im weiteren wurden das 1,2‐Dihydro‐(XVII),1,2,3,4‐Tetrahydro‐(XX) und N‐Methyl‐1,2,3,4‐tetrahydro‐olivacin (XIX) synthetisiert. Letzteres ist mit dem racemischen Alkaloid Guatambuin identisch. Für u‐Alkaloid D wird die Konstitution des 1,2‐Dihydroellipticin (XVIII) vorgeschlagen.
Über Pterinchemie. 3. Mitteilung. Reaktion von CN⊖ mit hydriertem 2‐Amino‐6‐hydroxy‐pteridin
Authors: Forrest H. S. , van Baalen C. , Viscontini M. , Piraux M.
Published: December 2004

The reaction of cyanide ion with reduced 2‐amino‐6‐hydroxy‐pteridine yields 2‐amino‐6‐hydroxy‐dihydro‐pteridine‐8‐carboxamide. Evidence is presented that the hydrogens are in the 7 and 10 positions. They can be readily removed by a number of mild oxidizing agents.
Chromatographie von Polyelektrolyten V. Aminoäthyl‐Cellulose und Guanidinoäthyl‐Cellulose
Authors: Semenza G.
Published: December 2004

Two new anion‐exchangers for protein chromatography have been prepared from cellulose: an aminoethyl‐ and a guanidoethyl‐cellulose. Their preparation, properties, and some examples of their application are reported. A cross‐linked cellulose has also been obtained.
Steroide und andere Inhaltsstoffe aus Stierhoden. Über Steroide, 171. Mitteilung
Authors: Neher R. , Wettstein A.
Published: December 2004

The neutral lipophilic ingredients of deep frozen testicular tissue of young bulls have been reinvestigated. Besides steroids known to occur in this type of tissue the following have been isolated for the first time: 17α‐hydroxyprogesterone, 3‐keto‐17α, 20α‐dihydroxy‐Δ4‐pregnene, 3‐keto‐17α, 20β‐dihydroxy‐Δ4‐pregnene, epi‐ testosterone, 6β‐hydroxytestosterone, 15α‐hydroxytestosterone, 16α‐hydroxytestosterone and 3β‐hydroxy‐17‐keto‐Δ5‐androstene (DHA). In addition the chromatographic identification of four other steroids has been accomplished for the first time: 7β‐hydroxycholesterol, progesterone, 3,11,17‐triketo‐Δ4‐androstene and 3β‐hydroxy‐17‐keto‐androstane.
Beobachtungen zur Synthese der 2‐Deoxy‐D‐ribose aus 1, 2; 5, 6‐Diisopropyliden‐3‐mesyl‐D‐glucose
Authors: Recondo E. , Rinderknecht H.
Published: December 2004

A simplified method for the preparation of 2‐deoxy‐D‐ribose from 1, 2; 5, 6‐diisopropylidene‐3‐mesyl‐D‐glucofuranose is described. Acid hydrolysis of the latter and alkaline degradation of 3‐mesyl‐D‐glucose are effected without isolation of intermediates, the whole operation requiring only 2½ hours. A specific «anion effect » on the velocity of this degradation and on the yield of 2‐deoxy‐D‐ribose anilide has been observed. The use of sodium carbonate gives particularly high yields of pure 2‐deoxy‐D‐ribose anilide. Improvements in the synthesis of 1, 2; 5, 6‐diisopropylidene‐D‐glucofuranose are described.
Anorganische Dünnschicht‐Chromatographie. 1. Mitteilung
Authors: Seiler H. M.
Published: December 2004

The thin layer (chromatoplate) method is applied to the separation and identification of mixtures of inorganic cations.
Welkstoffe und Antibiotica. 23. Mitteilung. Über die Isolierung von Culmomarasmin, einem peptidartigen Welkstoff aus dem Kulturfiltrat von Fusarium culmorum (W. G. SM.) SACC.
Authors: Kiss J. , Naef‐Roth St. , Hardegger E. , Boller A. , Lohse F. , Gäumann E. , Plattner Pl. A.
Published: December 2004

Aus dem Kulturfiltrat von Fusarium culmorum (W. G. SM.) SACC. wurde ein hoch wirksames Welketoxin, das Culmomarasminisoliert, das seinem chemischen Verhalten nach zu den Polypeptiden gehört.
Synthèse de nouvelles N‐alcoxy‐malonylurées hydroxylées et de leurs carbamates
Authors: Gold‐Aubert Ph. , Gysin E.
Published: December 2004

Some new carbamates and N‐substituted barbituric acids with carbamated side chain have been prepared. Several of these substances show interesting pharmacological properties.
Synthèse de la Ileu8‐oxytocine et de la Val8‐oxytocine, deux analogues de l'oxytocine modifiés dans la chaîne latérale
Authors: Jaquenoud P.‐A. , Boissonnas R. A.
Published: December 2004

N‐CBO‐L‐prolyl‐L‐isoleucyl‐glycine ethyl ester and N‐CBO‐L‐prolyl‐L‐valylglycine ethyl ester are synthesized by recurrent methods. Amidification of the ester group, splitting of the CBO group and condensation with N‐CBO‐L‐glutaminyl‐ L‐asparaginyl‐S‐benzyl‐L‐cysteinyl‐azide affords the two respective hexapeptides, which after splitting of the CBO group are condensed with N‐tosyl‐S‐benzyl‐L‐cysteinyl‐ L‐tyrosyl‐L‐isoleucyl‐azide. Cleavage of the protecting groups of the resulting two nonapeptides with sodium in liquid ammonia, oxydation with air in dilute aqueous solution and purification by counter‐current distribution, affords the desired cyclic nonapeptide amides : Ileu8‐oxytocin and Val8‐oxytocin. When tested on the cat uterus in situ the former is a stronger oxytocic than oxytocin itself.
Synthese von Peptid‐Zwischenprodukten für den Aufbau eines corticotrop wirksamen Nonadecapeptids. II. Derivate des L‐Seryl‐L‐tyrosyl‐L‐serins
Authors: Iselin B. , Schwyzer R.
Published: December 2004

The synthesis of t‐butyloxycarbonyl derivatives of L‐seryl‐L‐tyrosyl‐L‐serine and L‐seryl‐L‐tyrosyl‐L‐seryl‐L‐methionine is described. The azide method involving the conversion of a hydrazide into the corresponding azide under acidic conditions was found to be applicable, under carefully selected conditions, to the synthesis of t‐butyloxycarbonyl peptide derivatives in spite of the sensitivity of the protecting group toward strongly acidic reagents.
Synthèse de dihydro‐6,7‐imidazo[1,2−a]triazines‐1,3,5 disubstituées
Authors: Hinkens R. , Promel R. , Martin R. H.
Published: December 2004

Four 2,4‐disubstituted 6,7‐dihydro‐imidazo[1,2−a]‐s‐triazines (IV, VII, X and XV) have been synthesized according to the following scheme: (a) monosubstitution of cyanuric chloride (I) with ethanolamine, (b) replacement of the remaining chlorine atomes by suitable groupe, and (c) cyclisation of the 2′‐hydroxy‐ethylamino side chain on one of the adjacent cyclic nitrogen atoms of the s‐triazine nucleus. This last step includes reaction of the 2‐[(2‐hydroxy‐ethyl)‐amino]‐s‐triazines with thionyle chloride or p‐toluenesulfonyl chloride and, with one exception (VIII→IX), heating the resulting 2‐[(2‐chloro‐ethyl)‐amino] derivatives or p‐toluenesulfonic esters in a solvent.
Über die Struktur von Plumericin, Isoplumericin, β‐Dihydroplumericin und der β‐Dihydroplumericinsäure
Authors: Albers‐Schönberg G. , Schmid H.
Published: December 2004

Aus Plumeria rubra var. alba (Apocynaceae) wurden neben dem bereits bekannten Fulvoplumierin das schon früher aus PI. multiflora isolierte Plumericin, sowie neu Isoplumericin, β‐Dihydroplumericin und β‐Dihydroplumericinsäure isoliert. Die vier Stoffe wurden charakterisiert und ihre Konstitution und Stereochemie aufgeklärt.
Synthese von Dab 1‐Dab 9‐Bradykinin
Authors: Vogler K. , Studer R. O. , Lergier W.
Published: December 2004

Dab1‐Dab9‐bradykinin (Dab‐Pro‐Pro‐Gly‐Phe‐Ser‐Pro‐Phe‐Dab) has been prepared by a new procedure which differs from known syntheses of bradykinin. Against carboxypeptidase and chymotrypsin this synthetic analogue of bradykinin behaves in a way similar to that of the natural hormone, but it does not exhibit any pharmacological activity on the isolated rat uterus.
Isolierung, Struktur und Synthese von Pterinen aus Ephestia kühniella ZELLER. Vorläufige Mitteilung
Authors: Viscontini M. , Stierlin H.
Published: December 2004

Aus Ephestia kühniella Zeller wurden drei weitere Pterine, Erythropterin, Lepidopterin und Ekapterin, isoliert. Die Struktur von Ekapterin konnte ermittelt werden. Eine Synthese von Erythropterin und Ekapterin wird beschrieben.
Die Anwendung der elektronischen Rechenmaschine zur Lösung einiger Probleme der Komplexchemie
Authors: Anderegg G.
Published: December 2004

The author develops a method permitting the calculation, using a digital computer, of the concentration of the different complex ions present in a solution containing known amounts of ligand and of metal ion at a given pH.
Synthetische Versuche in der Gruppe der cytotoxisch wirksamen Substanzen Darstellung von DL‐ und L‐3‐[Di‐(β‐chloräthyl)‐amino]‐4‐hydroxy‐phenylalanin
Authors: Dall'Asta L. , Ferrario P.
Published: December 2004

Es wird die Darstellung des DL‐und des L‐3‐[Di‐(β‐chloräthyl)‐amino]‐4‐hydroxy‐phenylalanins auf zwei Wegen beschrieben. Die Verseifungsgeschwindigkeit des Halogens der β‐Chloräthyl‐Funktion genannter Produkte wird mit jener des DL‐para‐und des DL‐meta‐[Di‐(β‐chloräthyl)‐amino]‐phenylalanins verglichen.
Durch Umlagerung induzierte Fragmentierung von 4‐Tosyloxymethyl‐chinuclidin und vergleichende Solvolyse von 1‐Tosyloxymethyl‐bicyclo[2,2,2]octan und Neopentyltosylat Fragmentierungsreaktionen, 3. Mitteilung
Authors: Grob C. A. , Hoegerle R. M. , Ohta M.
Published: December 2004

A fragmentation reaction can be induced by generating a γ‐amino‐carbonium ion through a Wagner‐Meerwein rearrangement of a δ‐amino‐p‐toluenesulfonic ester. Thus solvolysis of 4‐tosyloxymethyl‐quinuclidine (9a) in aqueous ethanol yields the 4‐methylene‐1‐aza‐cycloheptanes (20a) and (20b).
Assoziation bei Azoverbindungen I: Einfluss von Substituenten auf die Basizität von 4‐Dimethylamino‐azobenzol‐Derivaten
Authors: Zenhäusern A. , Zollinger Hch.
Published: December 2004

The relative acidity constants K′ of derivatives of 3‐methyl‐4‐dimethyl‐amino‐azobenzene substituted in the 3′‐or 4′‐position follow the Hammett relationship for substituted benzene derivatives (ϱ = + 0.46)

The relative acidity constants of substituted mono‐protonated 4‐dimethyl‐amino‐azobenzenes (DAB) follow the Hammett relationship with most substituents (ϱ = + 0.77). Significant deviations are observed with ‐M‐substituents in 4′‐position (NO2, COCH3, CN): the acidifying effect of these substituents is smaller than expected

Molar extinction coefficients and acidity constants are dependent on the concentration of these DAB derivatives. It can be demonstrated that these compounds are highly aggregated, even in very dilute solutions.
In‐vitro‐Einbau radioaktiver Aminosäuren in die Proteine von Drosophila‐Puppen
Authors: Jenny E. , Hicklin A. , Leuthardt F.
Published: December 2004

The authors describe the incorporation of radioactive aminoacids into microsomes from Drosophila melanogaster (pupae). Enzymatic incorporation can only be shown after inhibition of a very active tyrosinase, which is present in the microsomal fraction, by phenylthiourea.
Fluoreszierende Stoffe aus Ephestia kühniella ZELLER 3. Mitteilung. Isolierung und Strukturen von Erythropterin, Ekapterin und Lepidopterin
Authors: Viscontini M. , Stierlin H.
Published: December 2004

Der Nachweis und die Isolierung von Erythropterin, Lepidopterin und Ekapterin aus Ephestia kühniella Zeller, sowie die wichtigsten Eigenschaften dieser Substanzen werden beschrieben. Für Lepidopterin und Ekapterin werden wahrscheinliche Strukturformeln abgeleitet.
Welkstoffe und Antibiotika. 24. Mitteilung. Die Konstitution des Lycomarasmins
Authors: Hardegger E. , Liechti P. , Jackman L. M. , Boller A. , Plattner Pl. A.
Published: December 2004

Über Derivate und Abbauprodukte gelang die eindeutige Festlegung der funktionellen Gruppen in Lycomarasmin, Lycomarasminsäure und Anhydro‐lyco‐marasminsäure (Substanz J), sowie die Ermittlung der L‐Konfiguration im Asparaginsäure‐Teil dieser Verbindungen. Durch Kombination der neuen Erkenntnisse mit den Ergebnissen früherer Untersuchungen konnten für die erwähnten Verbindungen je 2 Strukturformeln abgeleitet werden. NMR.‐Spektren erlaubten die überzahligen Varianten auszuschliessen und jeder der 3 Verbindungen die richtige Konstitutionsformel, bis auf die absolute Konfiguration eines einzigen C‐Atoms, zuzuschreiben.
Zur Struktur des Sikkimotoxins I. Synthese von stereoisomeren 6,7‐Dimethoxy‐Analogen des Podophyllotoxins. 11. Mitteilung über mitosehemmende Naturstoffe
Authors: Schreier E.
Published: December 2004

The total synthesis of several stereoisomeric 6,7‐dimethoxy‐analogues of podo‐phyllotoxin, the main component of the resin of Podophyllum elvzodi and P. peltatunt is described. One of the synthetic lactones, for which the name of picrosikkimotoxin is proposed, corresponds in its configuration to picropodophyllin, the compound produced from podophyllotoxin by base‐catalysed epimerisation. The structure corresponding to the synthetic picrosikkimotoxin has been assigned by CHATTERJEE and coworkers to the so called isosikkimotoxin, the product of the base‐catalysed epimerisation of sikkimotoxin, a new lignan lacton isolated in 1950 by the Indian group from the rhizomes of Podoflhyllurn sikkinzensis R. CHATTERJEE et MUCKERJEE, and thought to be analogous to podophyllotoxin. The properties of the synthetic, optically active picrosikkimotoxin, the structure and absolute configuration of which have been established unequivocally by stereochemical correlation with picropodophyllin, and of its acetyl derivative do not agree in all respects with published data for isosikkimotoxin and acetylisosikkimotoxin. This fact gives rise to some doubt as to the correctness of the proposed structure or the purity of the compounds from natural source. A direct comparison of the synthetic and natural compounds has not been possible, due to the unavailability of authentic material.
Recherches dans la série des cyclitols XXXIII. Sur quelques cyclitols dérivés du cyclopentane
Authors: Sable H. Z. , Anderson Thelma , Tolbert Bernadine , Posternak Th.
Published: December 2004

Par hydroxylation de cyclopenténediols‐3,4 et 3,5 cis ou trans, on a prèparè 5 cyclopentanetbtrols. L'un d'eux a ètè obtenu aussi par oxydation permanganique du cyclopentadiéne, à côtè d'un èpoxycyclopentanediol qui reprèsente peut‐êre un intermèdiaire. Un cyclopentanetriol et un cyclopentanepentol ont ègalement ètè prèparès. Le mode d'hydrolyse des èpoxydes de la sèrie du cyclopentane a ètè discutè.
Fragmentierung von α‐Aminoketoximen. III. Teil Mono‐ und bicyclische Verbindungen. Fragmentierungs‐Reaktionen. 6 Mitteilung
Authors: Grob C. A. , Fischer H. P. , Link H. , Renk E.
Published: December 2004

The only observable reaction of the p‐toluene sulfonates of six mono‐ and bicyclic α‐aminoketoximes (2d–7d) is fragmentation to carbimonium salts (8–13). The fragmentation product of 1‐keto‐octahydropyrrocolineoxime‐tosylate (6d), viz. the carbimonium salt (12), undergoes spontaneous ring closure to 2‐oxo‐1‐azaquinolizidine (26). The intermediate (12) in this fragmentation‐recombination reaction can be intercepted by cyanide ion, yielding β(2‐cyano‐piperid‐l‐yl)‐propionnitrile (29 a).
Synthese einiger auxochromhaltiger α,α‐Diaryläthylene und Stilbene
Authors: Al‐Attar Yousef , Wizinger Robert
Published: December 2004

Anisol, Phenetol, Thioanisol, p‐Kresolmethylather, Veratrol, 2,5‐Dimethoxy‐toluol, Pyrogalloltrimethyläther, α‐Naphtolathyläther werden mit Chlor‐ bzw. Bromacetal zu α, β‐Diaryl‐β‐halogenäthanen kondensiert, aus denen durch Abspal‐tung von Halogenwasserstoff rnit alkoholischem KOH die analogen α, α‐Diaryl‐äthylene in meist guter Ausbeute erhalten werden. Die auxochromhaltigen α, α‐Diaryl‐β‐halogenäthane, in höher siedenden Lösungsmitteln bei Abwesenheit von Alkali erhitzt, spalten Halogenwasserstoff unter Umlagerung in Stilbene ab; die Ausbeuten sind vielfach praktisch quantitativ.
Hydroxamatkomplexe I. Die Stabilität der Eisen(III)‐Komplexe einfacher Hydroxamsäuren und des Ferrioxamins B
Authors: Schwarzenbach G. , Schwarzenbach K.
Published: December 2004

The equilibria between iron(III), acethydroxamic acid, benzhydroxaminc acid, desferri‐ferrioxamin B and their iron complexes have been elucidated by combining redox potentials, pH and photometric measurements. For the results see section f above.
Über die Verrucarine und Roridine. 3. (vorläufige) Mitteilung. Struktur von Verrucarol
Authors: Gutzwiller J. , Tamm Ch.
Published: December 2004

Structure I is assigned to Verrucarol (C15H22O4).
Über die Inhaltstoffe von Zizphus oenoplia MILL. 1. Mitteilung: Isolierung der Inhaltstoffe
Authors: Ménard E. L. , Müller J. M. , Thomas A. F. , Bhatnagar S. S. , Dastoor N. J.
Published: December 2004

Two new basic peptides, Zizyphin (C33H49O6N5) and Zizyphinin (C32H47O6N5), have been isolated from the root bark of Zizyphus oenoplia MILL.
Recherches sur la formation et la transformation des esters XLIII. Sur la préparation de quelques monoesters de l'acide cyclohexanephosphonique
Authors: Cherbuliez Emile , Gowhari M. , Rabinowitz J.
Published: December 2004

Poly‐cyclohexanephosphonic acid is obtained very easily by heating cyclohexanephosphonic acid, under reduced pressure, at 180–190°C, for 96 to 150 hours.
Recherches sur la formation et la transformation des esters XLV. Sur la phosphonylation des hydroxyacides, des hydroxynitriles et des hydroxyesters
Authors: Cherbuliez Emile , Čolak‐Antić Sl. , Hunkeler F. , Rabinowitz J.
Published: December 2004

Carboxy‐alkyl phenylphosphonic monoesters are obtained very easily by selective hydrolysis (in alcaline medium) of the corresponding carbamido‐ or cyano‐alkyl phenylphosphonic monoesters and sometimes of the corresponding carbethoxy‐alkyl phenylphosphonic monoesters and sometimes of the corresponding carbethoxy‐alkyl phenylphosphonic monoesters and sometimes of the corresponding carbethoxy‐alkyl phenylphosphonic monoesters. This general procedure cannot be carried out when the −CONH2, −CN or −COOR groups are fixed on the C next to the one bearing the phenylphosphonic monoester group; in this case, the monoester group is also very quickly clived in alcaline medium.
Recherches sur la synthèse des acides gras XIII. Influence de l'acétazolamide seul ou associé à l'insuline sur la synthèse in vivo des acides gras chez la souris
Authors: Rous S. , Favarger P.
Published: December 2004

Mice were given acetazolamid orally or intravenously. Some of them were also given simultaneously insulin intraperitoneally. The synthesis of radioactive fatty acids was measured after injection of acetate‐[1‐14C] or glucose‐U‐14C. Administration of acetazolamid inhibits significantly the synthesis of fatty acids and hyperglycemia can be observed. The synthesis of palmitic acid is preferentially inhibited. Insulin injection suppresses this inhibition. These results are discussed in connection with a more specifical action on the non mitochondrial condensation system.
Organische Phosphorverbindungen X. Alkylierung von Phosphorthiohalogen‐Verbindungen mit aluminiumorganischen Verbindungen. Ein neues Verfahren zur Darstellung von Halogenverbindungen von Thiophosphonsäuren, Thiophosphinsäuren und tertiären Phosphinsulfiden
Authors: Maier Ludwig
Published: December 2004

The reaction of PSCl3, RPSCI2, (EtO)2PSCI, [(CH3)2N]2PSCl and PSBr3 with CH3AICl2, EtAlCl2, EtAI(OEt)2, Et3A1, Ph3A1 and (i‐C4H9)3Al has been studied. The preparation of thiophosphonic dihalides, RPSX2 [R =CH3, C2H5, i‐C4H9; X =C1, Br], thiophosphinic halides, RR′PSX [RR′ = C2H5, i‐C4H9, Ph; X = C1, Br, and R′ = CH3, R′ = C2H5, X =Cl], as well as tertiary phosphine sulfides, R3PS [R = C2H5, i‐C4H9, Ph] is described. The preparation of [(CH3)2N]2P(S)Et is also reported.
Etude des composés d'addition des acides de Lewis XXI. Constantes de Hammett et vibration carbonyle d'acétophénones para‐substituées et de leurs composés d'addition avec ZnCl2 et TiCl4
Authors: Rossetti G. P. , Susz B. P.
Published: December 2004

The perturbed carbonyl frequencies of the solid adducts of p‐substituted aceto‐ phenonones with ZnC12 and TiC14 resonating with the 8a and 8b benzene frequencies have been corrected by means of the theory of perturbation of nearly‐degenerated levels.
Beiträge zur Chemie der Si–N‐Bindung, VII. N,N′‐alkylierte und ‐arylierte Cyclodisilazane
Authors: Fink Walter
Published: December 2004

Cyclodisilazane mit alkyl‐ oder aryl‐substituiertem Stickstoff können aus den N, N′‐Diorgano‐silandiaminen I sowohl über die zweifache Metallierung von I und anschliessender Reaktion rnit Diorganosiliciumdichlorid als auch direkt durch deren Pyrolyse hergestellt werden :
magnified image
Synthese und BECKMANN‐Umlagerung von 1‐Acetyl‐bicyclo [2.2.2] octan‐oxim. Bicyclo [2.2.2] octan‐Reihe, 8. Mitteilung
Authors: Fischer H. J. , Grob C. A.
Published: December 2004

The synthesis of 1 ‐acetyl‐bicyclo[2.2.2]octane oxime is described. The p‐toluene‐sulfonic ester of this compound affords l‐acetamido‐bicyclo[2.2.2]octane (7) upon BECKMANN rearrangement, and therefore possesses the anti‐R/OTs configuration 6.1 ‐Acetamido‐bicyclo[2.2.2]octane (7) is also obtained by the HOFMANN reaction of l‐carbamoyl‐bicyclo[2.2.2]octane (3).
Selektive Reduktions‐ und Oxydationsreaktionen an lysergsäure‐ Derivaten. 2.3‐Dihydro‐ und 12‐Hydroxy‐lysergsäureamide. 59. Mitteilung über Mutterkornalkaloide
Authors: Stadler P. A. , Frey A. J. , Troxler F. , Hofmann A.
Published: December 2004

A stereoselective reduction of d‐lysergic acid amides to the 2,3‐dihydro derivatives is described. These new dihydro‐compounds can be dehydrogenated and oxidised with potassium nitroso‐disulphonate to form the corresponding 12‐hydrosy‐d‐lysergic acid amides besides the corresponding d‐lysergic acid amides.
6‐Methyl‐Δ8,9‐ergolen‐8‐carbonsäure, ein neues Ergolinderivat aus Kulturen eines Stammes von Claviceps paspali STEVENSet HALL. 60. Mitteilung über Mutterkornalkaloide
Authors: Kobel H. , Schreier E. , Rutschmann J.
Published: December 2004

Aus Paspalurn‐Mutterkorn, das von zahlreichen, über die ganze Erde verteilten Fundorten beschafft worden war, konnten mehrere Hundert Stamme isoliert und unter geeigneten Standardbedingungen in Submerskultur gezüchtet werden. Auf Grund der Zusammensetzung des von den untersuchten Stammen produzierten Al‐ kaloidgemisches, liessen sich drei «chemische Rassen» H definieren. Zur ersten, weit‐ verbreiteten Rasse gehören 98°%yo aller untersuchten Stamme. Ihr sind auch die bereits bekannten Claviceps‐paspali‐stamme von CHAIN, TONOLO et al. [7] [8] und von GROGER et al. [9] zuzuordnen. Als Hauptalkaloide finden sich hier das Amid und das Methylcarbinolamid der Lysergsäure (IIa, b) und der Isolysergsäure (IIIa, b). Bei der zweiten, in Argentinien gefundenen, neuen Rasse bestehen 75 bis 80°% yo aller Alkaloide aus Ergobasin IIc und Ergobasinin IIIc. Die dritte, ebenfalls neue chemische Rasse, die bisher nur in Portugal gefunden wurde, bildet ein Gemisch fast ausschliesslich amphoterer Produkte, das neben Lysergsäure (I)zu über 70% aus der bisher unbekannten 6‐Methyl‐Δ8,9‐ergolen‐8‐carbonsäure (IV) besteht.
Metallindikatoren VII. Die Aciditätskonstanten und der Eisenkomplex des N,N′‐Äthylen‐bis‐(o‐hydroxyphenyl‐glycins (EHPG))
Authors: Anderegg G. , L'Eplattenier F.
Published: December 2004

The acidity constants of N, N′‐Ethylene‐bis‐(o‐hydroxyphenyl‐glycine) (= EHPG)have been determined. The stability constant of the 1:1 complex with trivalent iron has been determined from optical measurements of the equilibrium with trimethylene‐diamine‐tetraacetic acid. Among the studied ligands EHPG forms the stablest 1:1 complex with iron(II1). This red complex can be used in acid solution as indicator for the complexometric titration of iron.
Die Strukturen der mittleren Ringverbindungen VIII. Azacyclododecan‐hydrochlorid
Authors: Dunitz J. D. , Weber H. P.
Published: December 2004

Crystals of azacyclododecane hydrochloride (a = 13.77, b = 5.07, c = 9.67 Å, α = 109°26′, β = 90°22′, γ = 101°16′) and hydrobromide (a = 13.53, b = 5.19, c = 9.45 Å, α = 99°40′, β = 83°57′, γ = 98°28′) are isomorphous, space group P1, Z = 2. The conformation of the 12‐membered ring has been established from three‐dimensional X‐ray analysis. It corresponds closely to the idealized model with 422‐symmetry, containing 8 syn‐clinal and 4 anti‐periplanar partial conformations.
Komplexone XXXVI. Reakinsenthalpie und ‐entropie bei der Bildung der Metallkomplexe der höheren EDTA‐Homologen
Authors: Anderegg G.
Published: December 2004

Complexing agents of the type (−OOCCH2)N(CH2)nN(CH2COO−)2, with n values from 2 to 8, have been investigated. The stability constants and the heats evolved by formation of the 1:1‐complexes of Ca2+, Mg2+, Mn2+, Fe2+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+, Pb2+, Hg2+ and La3+ have been determined. From the behaviour in complex formation reaction these cations can be divided into two groups. In the first one, including the A‐cations Ca2+, Mg2+, Mn2+, Cd2+, Pb2+ and La3+, the stability constants and −ΔH by formation of the 1:1‐complexes decrease rapidly when n is increased from 2 to 4. The second one contains all other metal ions investigated except Hg2+, and the drop in stability is observed between n = 4 and n = 5, whereas −ΔH slightly increases. Comparing the enthalpy values by formation of the complexes with cations of the first group of iminodiacetate and of EDTA (Table S), a considerable −ΔH increment is observed. The entropy gain by complex formation is approximately the same if the number of methylene groups in the chain connecting the two nitrogens is increased from 2 to 4. Replacement of one or two of these CH2− groups by 0 or S decreases generally the free energy and the enthalpy of complex formation to a great extent if new 5‐membered chelate rings are formed.
Die synchrone Fragmentierung von γ‐Amino‐cycloalkylhalogeniden 1. Teil. Die Solvolyse von 1‐Amino‐3‐brom‐adamantanen. Fragmentierungs‐Reaktionen. 10. Mitteilung
Authors: Grob C. A. , Schwarz W.
Published: December 2004

The stereochemical requirements for the concerted one‐step fragmentation mechanism of γ‐aminohalides (R2NCCC‐Hal) are discussed. 1‐Amino‐3‐bromo‐adamantane (12a) and its N‐methyl‐ and N,N‐dimethyl derivatives 12b and 12c, respectively, react by the concerted mechanism involving five atomic centers in the transition state. This is inferred from the exclusive formation of fragmentation products and from the enhanced reaction rates in «80%» ethanol as compared with the solvolysis rates of the homomorphous 1‐alkyl‐3‐bromo‐adamantanes 13a–c. The minimum values of the frangomeric accelerations for 12a, b and c are 30, 222 and 520 respectively. The fragmentation rates of the three 1‐amino‐3‐bromo‐adamantanes 12a–c increase in the order NH2 < NHCH3 < N(CH3)2.
Recherches sur la formation et la transformation des esters LVI. Action de l'acide sulfurique sur les aminoalcools
Authors: Cherbuliez Emile , Chapalay C. , Čolak‐Antić Sl. , Marszalek J. , Vallet L. , Rabinowitz J.
Published: December 2004

By heating an equimolecular mixture of an amino alcohol and H2SO4 during an appropriated time (half an hour to some hours) at 180–200°C under reduced pressure, the corresponding aminoalkyl sulfuric monoester is obtained in very good yield.
Cycloenantiomerie und Cyclodiastereomerie 2. Mitteilung. Über cycloenantiomere cyclo‐Hexaalanyle und ein cycloenantiomeres cyclo‐Diglycyl‐tetraalanyl
Authors: Gerlach H. , Owtschinnikow J. A. , Prelog V.
Published: December 2004

The cyclo‐hexaalanyls I, II and cyclo‐diglycyl‐tetraalanyl XXX have been prepared and investigated as examples of cycloenantiomeric compounds.
CLAISEN'sche Umlagerungen bei Allyl‐ und Benzylalkoholen mit Hilfe von Acetalen des N, N‐Dimethylacetamids. Vorläufige Mitteilung
Authors: Wick A. E. , Felix Dorothee , Steen Katharina , Eschenmoser A.
Published: December 2004

The preparative utility of the reaction between N, N‐dimethylacetamide‐dimethylacetal and allylic or benzylic alcohols to form N, N‐dimethylamides of γ, δ‐unsaturated acids or arylacetic acids is exemplified.
Fixation spontanée de la biotine à une protéine dans le Sérum humain
Authors: Vallotton M. , Hess‐Sander U. , Leuthardt F.
Published: December 2004

Biotin has been found to be bound spontaneously and irreversibly by a protein fraction from human serum. The nature and characteristics of this fraction are studied with the help of dialyse‐equilibration and gel‐filtration on Sephadex G‐200.
Methyläther von Carotinoiden. Konfiguration des Azafrins
Authors: Müller H. , Karrer P.
Published: December 2004

Die Herstellung von Methyläthern des Xanthophylls, Zeaxanthins, Capsanthins und Azafrins wird beschrieben, und es wird zur Frage der Konfiguration des Azafrins Stellung genommen.
Die Strukturen zweier 1:2‐Chromkomplexe von o, o′‐Dihydroxydiaryl‐trans‐azo‐Farbstoffmolekeln
Authors: Grieb Rita , Niggli A.
Published: December 2004

The crystal structure determinations of two pyridinium salts of 1:2‐chromium complexes formed by o,o′‐dihydroxy‐trans‐azo molecules show that the structure of the anions corresponds to the DREW‐PFITZNER arrangement [2], as postulated by G. SCHETTY [1] for cases where the ligands form five‐ and six‐membered rings with the metal ion. The correct structure formulae are given (cf. formulae I and II); as the refinement of both structures is still going on, further details (such as bond lengths and bond angles) will be published in Z. Krist.
Alkaloid‐Studien LII. Die Alkaloide aus Vallesia dichotoma RUIZet PAV
Authors: Walser A. , Djerassi Carl
Published: December 2004

A total of 28 indole and dihydroindole alkaloids have so far been isolated from the bark or leaves of Vallesia dichotoma RUIZ et PAV. All but seven of these alkaloids have been characterized largely through the combined use of UV.‐, IR.‐ and NMR.‐spectroscopy as well as mass spectrometry. Their structures are listed together with other data in a table.
Zur Kenntnis der Hexaalkylbenzole. 5. Mitteilung. Über die Struktur der Dienaddukte des Hexaäthylidencyclohexans
Authors: Hopff H. , Kormany G.
Published: December 2004

The diadduct of hexaethylidenecyclohexane with maleic acid anhydride is shown to have a linear structure, giving anthracene and anthracene derivatives by dehydrogenation and decarboxylation.
Struktur und Synthese von Evolidin
Authors: Studer R. O. , Lergier W.
Published: December 2004

The structure proposed for Evolidine, a cyclic heptapeptide isolated from the leaves of Evodia xanthoxyloides, is confirmed by degradation of the natural product and by synthesis.
Étude de composés d'addition des acides de LEWIS. XXIV. Mise en évidence par absorption infrarouge de l'ion mésitoylium dans H2SO4 concentré et l'oléum
Authors: Oulevey G. , Susz B. P.
Published: December 2004

The existence of the mesitoyl ion in solutions of mesitoic acid in concentrated H2SO4 and in oleum has been confirmed by infrared absorption spectra which show the characteristic 2190 cm−1 band already found in some addition compounds of mesitoic acid and mesitoyl chloride with LEWIS acids.
Recherches sur la formation et la transformation des esters LVIII. Sur la réaction de l'isothiocyanate de phényle avec quelques diols
Authors: Cherbuliez Emile , Marszalek J. , Rabinowitz J.
Published: December 2004

By reacting phenylisothiocyanate with several diols (ranging from 1,3 to 1,10 diols) at temperatures between 65–140°C for 2 to 14 hours in the presence of pyridine, thiocarbamylated derivatives of the diols are produced.
Autoxydation N2‐substituierter Methylhydrazine; Beeinflussung der Cu‐ & Fe‐Katalyse durch Proteine, Desoxyribonucleinsäure (DNS) und EDTA
Authors: Aebi H. , Dewald Beatrice , Suter Hedi
Published: December 2004

1. Autoxidation of natulan and other methylhydrazine derivatives has been investigated by WARBURG'S direct manometric method. These compounds are relatively stable in a heavy‐metal‐free environment at pH 7.0, but are rapidly oxidised if a suitable catalyst is added.
Über den Mechanismus der Trypsin‐katalysierten Ester‐Hydrolyse: Modellversuche an Substraten
Authors: Gemperli Margrit , Hofmann Werner , Rottenberg Max
Published: December 2004

At both alkaline and neutral pH, tosyl‐L‐arginine ethyl ester hydrolyzes slower than benzoyl arginine ester, in disaccordance with the rules of inductive effects. Glycine and sarcosine esters however behave «normally», the tosyl derivatives reacting faster than the benzoyl. Tosyl‐L‐arginine esters are better substrates for trypsin than the corresponding benzoyl‐L‐arginine esters. It is concluded that the mechanism of trypsincatalyzed ester hydrolysis (deacylation) is fundamentally different from both neutral and alkaline hydrolysis.
Elektronenspinresonanz‐Untersuchungen von VO2+‐Komplexverbindungen in wässeriger Lösung II
Authors: Wüthrich K.
Published: December 2004

Complex formation between vanadyl(IV) ion and Tiron, and sulfosalicylic acid respectively, has been investigated by means of electron paramagnetic resonance (e.p.r.) and optical spectroscopy. The 1:1‐ and 1:2‐complexes are distinguishable by the position of the absorption maxima in the optical absorption spectrum as well as by the parameters of the e.p.r. spectrum. There is no evidence for the existence of stable hydroxo‐complexes. The influence of the ligands on the vanadium nuclear hyperfine splitting constant in the e.p.r. spectrum is discussed in terms of spin polarization.
Stereochemie von Betanidin und Isobetanidin. 8. Mitteilung. Zur Konstitution des Randenfarbstoffes Betanin
Authors: Wilcox M. E. , Wyler H. , Dreiding André S.
Published: December 2004

The base exchange of betanidin and isobetanidin with 5,6‐dihydroxy‐2,3‐dihydroindole‐2R‐carboxylic acid (named R‐Cyclodopa, III) led to the formation of enantio‐isobetanidin and enantio‐betanidin, respectively. The enantiomers exhibited rotatory dispersion curves which were the mirror images of those of betanidin and isobetanidin. Thus it is shown that, in agreement with our proposed structure for betanidin, there exists in the molecule another, and only one other, asymmetric centre in addition to that present at C2, and furthermore, that isobetanidin differs from betanidin only in its configuration at this second centre (C15).
Harze mit Einschlusshohlräumen von Cyclodextrin‐Struktur
Authors: Solms J. , Egli R. H.
Published: December 2004

A mixture of alpha‐, beta‐, and gamma‐cyclodextrins is cross‐linked with epichlorhydrin in alkali, giving a stable resin with glyceryl bridges between the cyclodextrin units. The resin forms specific inclusion complexes with many compounds. Isotherms of this process have been determined in aqueous solutions with benzaldehyde, aniline, p‐ and o‐nitrophenol, pyridine, butyric acid, iodine in potassium iodide, Congo red, methylorange, and methylene blue. For comparison isotherms have also been determined with the same substances for a commercial cross‐linked dextran without inclusion properties. The data illustrate a considerable ability of the cyclodextrin resin to form inclusion compounds.
Konstellation und Solvolysegeschwindigkeit der 1‐Decalyl‐p‐toluolsulfonate
Authors: Grob C. A. , Tam S. W.
Published: December 2004

The NMR.‐spectra of the four 1‐decalols and of their p‐toluenesulfonates have been determined. They are in agreement with accepted configurational assignments. Low‐temperature NMR.‐spectra of the cis‐1‐decalols indicate the predominance of conformation 7a in the case of the cis‐cis isomer m.p. 93° and a conformational equilibrium 8a⇄8b in the case of the cis‐trans isomer m.p. 55°.
Über die Chemie des Vitamins K. 2. Mitteilung. Totalsynthese und Stereochemie von trans‐ und cis‐(7′R, 11′R)‐Phyllochinon und verwandten Verbindungen
Authors: Jackman L. M. , Rüegg R. , Ryser G. , von Planta C. , Gloor U. , Mayer H. , Kofler M. , Isler O. , Schudel P.
Published: December 2004

The synthesis of trans‐ and cis‐(7′ R,11′ R)‐phylloquinone, trans‐ and cis‐menaquinone‐2, trans‐ and cis‐(7 R,11 R)‐phytol, and related compounds is described. Natural phylloquinone, isolated from alfalfa, is shown to possess the 2′,3′ ‐trans configuration.
Reaktionen mit Mikroorganismen. 14. Mitteilung [1] Reduktion von stereoisomeren Dekalonen‐(1) und einigen verwandten bicyclischen und tricyclischen Ketonen durch Curvularia falcata
Authors: Acklin W. , Prelog V. , Schenker F. , Serdarević B. , Walter P.
Published: December 2004

Racemic, stereoisomeric decal‐1‐ones and several related bicyclic and tricyclic ketones have been reduced microbiologically with high stereospecificity by Curvularia falcata (TEHON) BOEDIJN. The constitution, and the relative and absolute configuration, of the products have been determined.
Experimentelle Beiträge zum MILLS‐NIXON‐Effekt I: Magnetische Kernresonanzspektren von 5‐Hydroxyindan und 6‐Hydroxytetralin 17. Mitteilung zur Kenntnis der Azokupplungsreaktion [1]
Authors: Koch W. , Zollinger Hch.
Published: December 2004

5‐hydroxyindane and 6‐hydroxytetralin and their respective anions have been investigated by proton magnetic resonance spectroscopy. The results indicate that by forming the anion of 5‐hydroxyindane, the increase of electron density is the greatest at position 6, in agreement with its abnormal reactivity (Mills‐Nixon effect [2]).
Über eine neue allgemeine Synthese von 3,3‐disubstituierten 2,3,4,5‐Tetrahydro‐1H‐(benzo[b]1,4‐diazepin)‐2‐onen durch Ringerweiterung 3,3‐disubstituierter 1‐(o‐Aminophenyl)‐azetidin‐2‐one
Authors: Nicolaus Bruno J. R. , Bellasio Elvio , Pagani Giuseppe , Mariani Luigi , Testa Emilio
Published: December 2004

Es wird über eine intramolekulare Umamidierung berichtet, welche in guter Ausbeute von den viergliedrigen 3,3‐disubstituierten 1‐(o‐Aminophenyl)‐azetidin‐2‐onen (V) durch Ringerweiterung zu den siebengliedrigen 3,3‐disubstituierten 2,3,4,5‐Tetrahydro‐1H‐(benzo[b]1,4‐diazepin)‐2‐onen (VII) führt. Neben der Synthese wird über die chemischen und physikalisch‐chemischen Eigenschaften dieser neuen Verbindungen, über deren IR.‐ und NMR.‐Spektren sowie über einige ihrer Umsetzungen ausführlich berichtet. Der mutmassliche Mechanismus dieser Umlagerung wird diskutiert. Diese Synthese stellt zugleich den ersten allgemeinen Weg zur einfachen Darstellung der bis heute noch nicht beschriebenen 3,3‐disubstituierten 2,3,4,5‐Tetrahydro‐1H‐(benzo[b]1,4‐diazepin)‐2‐one (VII) dar.
Kobalt(III)‐Komplexe von N, N, N′, N′‐Tetrakis‐(β‐aminoäthyl)‐äthylendiamin (= «penten»)
Authors: Emmenegger F. P. , Schwarzenbach G.
Published: December 2004

Several salts containing the cation Co(penten)3+, in which the hexamin «penten» (formula: page 625) acts as a sexadentate ligand, have been synthesized and characterized. Its optical antipodes have been separated in some of the salts (Fig. 4), and the rate of racemization studied. In strongly alkaline solution one of the 5 chelate rings slowly opens and Co(penten)OH2+ is produced (Fig. 1), to which a first proton can be attached at the terminal NH2‐group (→ Co(Hpenten)OH3+), and a second which converts the hydroxo‐complex into the aquo‐complex (→ Co(Hpenten)OH4+). The equilibria between Co(penten)3+, Co(penten)OH2+, Co(Hpenten)OH3+ and Co‐(Hpenten)OH24+ have been elucidated, and the kinetics of the ring opening and ring closing reactions have been studied. Ring opening and ring closure take place with retention of configuration. It proved impossible to open two of the chelate rings of Co(penten)3+. Cristalline salts with cations of the general formula Co(penten)X3−λ or Co (Hpeten)X4−λ, with Xλ−  OH−, H2O, F−, Cl−, Br−, J−, SCN−, NO2,− and CO32−, have been obtained and characterized (Fig. 1, 2, 7 and Table 1).
Metallionen und H2O2. IV. Über Struktur und Aktivität der den H2O2‐Zerfall katalysierenden Cu2+‐Komplexe. II. Einfluss der Zahl der freien Koordinationsstellen
Authors: Sigel H. , Müller U.
Published: December 2004

The Cu2+ chelates of the bidentate ligands 2,2′‐bipyridine (I; [2]), N, N′‐diglycyl‐1,5‐diaminopentane (VI), ethylenediamine (II; [2]), glycine (V) and pyrophosphate (III; [2]) are found–parallel to the spectrochemical series–to be more active in catalysis of H2O2 decomposition than the chelates of the terdentate ligands–antiparallel to the spectrochemical series–iminodiacetic acid (IX), glycylglycine (VIII), 2, 2′‐diaminodiethylamine (VII) and 2, 2′, 2″‐terpyridine (IV; [2]), the activity decreasing in the given series. If all four coordination positions of Cu2+ are engaged (e.g. complex with N, N′‐di‐(2‐aminoethyl)‐ethylenediamine (X)) the complex is inactive. The catalytic activity of the Cu2+‐chelates is parallelled by the tendency to form ternary peroxo complexes.
Hydrolyse und Alkoholyse von Reaktivfarbstoffen: II. Hydrolyse von Monochlortriazin‐Farbstoffen. 2. Mitteilung über reaktionsmechanistische Untersuchungen an Reaktivfarbstoffen
Authors: Datyner A. , Rys P. , Zollinger Hch.
Published: December 2004

The kinetics of the hydrolysis of three monochlorotriazine reactive dyes have been determined in alkaline buffer solutions at 60°, 80° and 98° (ionic strength I = 0.0625).

The kinetic results as well as diffusion measurements in aqueous solution indicated that these dyes form aggregates at dye concentrations at 6 · 10−4, but practically not at 6·10−6 moles/l.

The reaction order with respect to hydroxyl ions has been determined. The influence of general base concentration was negligible.
Substitutions‐ und Eliminationsreaktionen an Aluminiumoxid: 1α‐ und 1β‐Benzoyloxy‐Δ2‐cholesten und 3β‐Chlor‐Δ1‐cholesten
Authors: Mühle H. , Orosz E. , Tamm Ch.
Published: December 2004

The formerly discribed [1] unknown substance CHT 208, which was obtained as side product when 3β‐benzoyloxy‐Δ1‐cholestene (3) was treated with ‘neutral’ activated alumina in an unpolar solvent, has been recognized as consisting of ca. 67% 3β‐hydroxy‐Δ1‐cholestene (6) and of ca. 33% 3β‐hydroxy‐Δ1‐cholestene (4) (molecular compound 2:1). Analogous treatment of 3β‐chloro‐Δ1‐cholestene (5) with alumina yielded the same mixture of the allylic alcohols 4 and 6 as substitution products and of Δ1,3‐cholestadiene (2) as elimination product in equal amounts.
Über spezifisch adsorbierende Silicagele V
Authors: Bartels H. , Prijs B. , Erlenmeyer H.
Published: December 2004

‘Printing’ experiments with optical stereoisomers indicate that footprints in specifically adsorbing silica gels consist mainly of a two‐dimensional arrangement of signs.
Chemische Aspekte der Penicillin‐Allergie: die direkte Bildung der Penicilloyl‐Determinanten aus Penicillin
Authors: Schneider C. H. , De Weck A. L.
Published: December 2004

The aminolysis of two penicillin‐like compounds which cannot form penicillenic acid has been studied:

6‐Aminopenicillanic acid (which is highly immunogenic) reacts directly with ε‐amino groups at pH 7,4 under CO2‐free conditions; the possible role of its polymerisation in this reaction remains to be studied.

6‐Dinitrophenylamino‐penicillanic acid reacts with εamino groups at pH 7,4 as fast as benzylpenicillin and other penicillins. Its immunogenicity in the rabbit is similar to that of benzylpenicillin.
Un substrat pour le dosage chimique de la rénine
Authors: Roth M. , Reinharz Anja
Published: December 2004

A fluorogenic renin substrate, N‐CBO‐L‐prolyl‐L‐phenylalanyl‐L‐histidyl‐L‐leucyl‐L‐leucyl‐L‐valyl‐L‐tyrosyl‐L‐seryl‐β‐naphthylamide, has been synthesized. Upon incubation at pH 5,6 with renin and an excess of the auxiliary enzyme aminopeptidase M, it gives rise to β‐naphthylamine at a rate related to the quantity of renin.
Die Kristallstruktur von 1,4‐trans‐Cyclohexan‐dicarbonsäure
Authors: Dunitz J. D. , Strickler P.
Published: December 2004

Crystals of 1,4‐trans‐cyclohexane‐dicarboxylic acid are monoclinic, a = 5.60 Å, b = 9.63 Å, c = 8.05 Å, γ = 107°14′, space group P21/b (first setting), with 2 centrosymmetric molecules in the unit cell. The structure has been solved by direct methods and refined by full‐matrix least‐squares analysis of three‐dimensional intensity data. The mean CCC‐angle in the cyclohexane ring is found 112.0°. The conformation of the carboxylic group in various acids is discussed.
Die sterischen Bedingungen der Fragmentierungsreaktion I. Teil. Stereoisomere 3‐Chlortropane. Fragmentierungsreaktionen, 14. Mitteilung
Authors: Bottini A. T. , Grob C. A. , Schumacher E. , Zergenyi J.
Published: December 2004

The steric requirements for the synchronous fragmentation of γ‐aminohalides as previously postulated have been confirmed by a study of the solvolysis of stereoisomeric 3β‐ and 3β‐chloro‐tropanes and ‐nortropanes. 3β‐chloro‐tropanes (7 a) and 3β‐chloro‐nortropane (7 b), which fulfil the stereoelectronic requirements, undergo quantitative fragmentation in 80 vol.% ethanol. They react 1.35 × 104 and 1.35 × 103 times, respectively, as fast as the ‘homomorphous’ exo‐3‐chloro‐bicyclo[3.2.1]octane (12 a). Fragmentation therefore takes place by the synchronous mechanism.
Eine vielstufige Verteilungsapparatur
Authors: Signer R. , Arm H.
Published: December 2004

A method of countercurrent distribution described ten years ago has been improved to get better resolution. Retaining the principle of fast establishment of liquid‐liquid equilibrium without emulgation, the rotating aggregate of separating chambers is not held horizontal, but inclined at an angle of 45°. The light mobile phase flows in every chamber as a thin layer over the heavy stationary phase. The separation of mixtures is analogous to that in a chromatographic column. The number of chambers can be easily increased to several hundred without complicating the handling of the apparatus. Another advantage consists in the complete absence of emulgations, even with systems or components that emulgate very easily. The apparatus can be operated under exclusion of oxygen.
Gas‐chromatographische und massenspektrometrische Untersuchung von Vitamin‐B6‐Trimethylsilderylderiveten
Authors: Richter W. , Vecchi M. , Vetter W. , Walther W.
Published: December 2004

Pyridoxine and pyridoxal are suitable for gas‐chromatographic analysis after conversion into their trimethylsilyl derivatives. Silylation proceeds rapidly and quantitatively, pyridoxal reacting in its hemiacetal form. The mass spectra of both derivatives are discussed.