bluuebunny/crossref_metadata_2025_split huggingface dataset:
Isolement et identification de composés phénoliques et monoterpéniques de la mousse de chêne (Evernia prunastri (L.) Ach.)
Authors: Gavin José , Tabacchi Raffaele 
Published: December 2004

AbstractThe composition of different oakmoss extracts was investigated by combined gas chromatography/mass spectrometry. A series of 38 compounds – especially phenol derivatives and monoterpenes – was identified, 22 of which have not yet been reported as constituents of oakmoss.
Synthetische Juvenilhormone 3. Mitteilung. p‐Substituierte 4‐Phenyl‐buten(1)‐carbonsäurederivate
Authors: Franke Albrecht , Mattern Günter , Traber Walter 
Published: December 2004

AbstractThe syntheses of p‐substituted 2‐methyl‐4‐phenylbuten(1)‐carboxylic acid derivatives are described, using Blanc's chloromethylation reaction, the Friedel‐Crafts alkylation of unsaturated ketones or the Meerwein arylation; the formed intermediates react in subsequent steps to the title compounds.
Conformation of Some Anomeric O‐Benzylated D‐gluco‐, L‐Ido‐, and Hex‐4‐enopyranoside derivatives
Authors: Kiss Joseph , Arnold Wolf 
Published: December 2004

AbstractBy use of 1H‐NMR. spectroscopy it is shown that in the anomeric tri‐O‐benzyl derivatives of D‐gluco‐ and L‐idopyranosides the C(5) (aliphatic) substituent has a strong tendency to assume an equatorial position. The conformer (4C1 or 1C4) with C(6) in equatorial position is favoured, even if other bulky substituents are forced to occupy an axial position; the same effect is observed in some anomeric O‐benzylated 6‐deoxy‐L‐idopyranoside derivatives.If, however, the tetragonal configuration of the saturated C(5) is changed into a trigonal (sp2) configuration, e.g. in the anomers of 1,2,3‐tri‐O‐benzylated L‐threo‐hex‐4‐enopyranosiduronates, the C(5)–C(6) bond no longer determines the equilibrium of (distorted) pyranoid conformations; the anomeric (‘Eduard‐Lemieux’) effect then becomes important in the stabilization of the corresponding half‐chair (1H2 or 2H1) conformations.
Notiz zur Synthese von 1‐Aryl‐ und 1‐Alkyl‐2, 3‐dimethyl‐chinoxaliniumperchloraten
Authors: Schelz Dieter , Priester Martin 
Published: December 2004

AbstractSome 1‐substituted 2, 3‐dimethyl‐quinoxalinium‐perchlorates were synthesized by reaction of butane‐2, 3‐dion with N‐monosubstituted 1,2‐diamino‐benzenes in strongly acidic solution. 2, 3‐dimethyl‐4‐cyclohexyl‐pyrido[2,3‐b]pyraziniumperchlorate was obtained from an analogous reaction.
Synthèse de sucres aminés ramifiés III. Synthèse et réactions de 1′α‐amino‐nitrile dérivé du di‐O‐isopropylidène‐1,2:5,6‐α‐D‐ribo‐hexofurannosul‐3‐ose
Authors: Bourgeois Jean‐Marc 
Published: December 2004

AbstractThe addition of cyanohydric acid to 1,2:5,6‐di‐O‐isopropylidene‐α‐D‐ribo‐hexofurannos‐3‐ulose can be sterically controlled. Under kinetic conditions, the allo cyanohydrine epimer is formed, under thermodynamic conditions, the gluco epimer is formed. The configuration of these two products is proved by their chemical reactions. Hydration followed by hydrolysis of the nitrile group of the allo epimer (O‐acetyl derivative) gives the 3‐C‐carboxy‐1,2‐O‐isopropyloidene compound.This product forms the corresponding γ or δ‐lactone with hydroxyl (5) or (6). On the other hand, after hydrolysis of 5,6‐isopropylidene, the 3‐O‐acetyl derivative of the gluco epimer gives an acetyl migration from position 3 to position 5 and finally to position 6. By reaction of the allo epimer with NH3 and CN−, an aminonitrile is formed. The allo configuration is deduced from the above mentioned reaction and from IR. and NMR. data. Several acetylated and trifluoracetylated derivatives of these products are described. The oxidation of the nitrile group to the amide group is possible with both epimeric cyanohydrines and the amino‐nitrile.
Biosynthese der Verrucarine und Roridine. Teil 3. Der Einbau von (3R)‐[5‐14C]‐, [2‐14C]‐ und an C(2) stereospezifisch tritiiertem Mevalonat in Verrucarol Verrucarine und Roridine, 29. Mitteilung
Authors: Müller Beat , Achini Roland , Tamm Christoph 
Published: December 2004

AbstractSeparate experiments, involving incorporation of either (3R)‐[5‐14C]‐mevalonate or each enantiomer of [2‐3H]‐mevalonate into verrucartin A and roridin A, indicate that hydroxylation at C(4) of the tricothecane skeleton, to yield verrucarol (4), proceeds with an overall retention of configuration; they confirm that C(8) and not C(10) is derived specifically from C(2) or mevalonate.
Biosynthesis of the Verrucarins and Roridins. Part 4. The mode of incorporation of (3R)‐[(5R)‐5‐3H]‐mevalonate into verrucarol. Evidence for the identity of the C(11)‐hydrogen atom of the trichothecane skeleton with the (5R)‐hydrogen atom of (3R)‐mevalonic acid
Authors: Müller Beat , Tamm Christoph 
Published: December 2004

AbstractIncorporation of (3R)‐[(5R)‐5‐3H]‐mevalonate into verrucarin followed by hydrolyses to verrucarol (2) and transformation of the latter to the spirolactol 5 and the spirolactone 6 successively, demonstrate the identity of the C(11)‐hydrogen of the trichothecane skeleton with the 5‐‘pro‐R’ hydrogen atom of (3R)‐mevalonate.
Hydrazide as a Carboxyl Protecting Group deprotection by acidolysis
Authors: Schnyder Jörg , Rottenberg Max 
Published: December 2004

AbstractElimination of the hydrazide group was studied with the model compounds N‐benzoyl‐glycine hydrazide and N‐benzoyl‐L‐phenylalanine hydrazide, using phosphorus oxychloride, hydrogen bromide or hydrogen chloride in acetic acid, or 60% perchloric acid. It was found that treatment of N‐benzoyl‐L‐phenylalanine hydrazide with perchloric acid gave N‐benzoyl‐L‐phenylalanine in 100% yield and without racemisation.
The Preparation of trans‐N‐Acyl, N‐alkyl‐1‐amino‐1,3‐butadienes. Preliminary communication
Authors: Oppolzer Wolfgang , Fröstl Wolfgang 
Published: December 2004

AbstractIn der vorliegenden Mitteilung wird erstmals ein Zugang zu trans‐N‐Acyl,N‐alkyl‐1‐amino‐1,3‐butadienen 4, sowie zu trans‐N‐Acyl, N‐aryl‐1‐amino‐1,3‐butadienen 4 beschrieben. Deprotonierung von N‐substituierten 1‐Imino‐2‐butenen 2 führt vermutlich zu den nicht isolierten delokalisierten Anionen 3, die anschliessend regioselektiv am Stickstoffatom acyliert werden.
A stereoselective approach to cis‐ and trans‐1,2,3,4,4,4a,5,6,8a‐octahydroquinolines by intramolecular Diels‐alder reactions preliminary communication
Authors: Oppolzer Wolfgang , Fröstl Wolfgang 
Published: December 2004

AbstractN‐Acyl‐N‐(4‐penten‐1‐yl)‐1‐amino‐1, 3‐butadiene (1) isomerisieren sich bei 190–215° über eine intramolekulare Diels‐Alder‐Reaktion stereoselektiv zu cis‐ verknüpften Octahydro‐chinolinen 2. Unter den gleichen Bedingungen erhält man aus dem N(Pent‐4‐enoyl)‐N‐propyl‐1‐amino−1, 3‐butadien (4) überwiegend das trans‐verknüpfte Octahydrochinolin‐2‐on 5 neben dem cis‐Isomeren 6. Diese Selektivität wird auf eine bevorzugte koplanare Anordnung von Amid‐ und Dien‐System im Übergangszustand zurückgeführt.
The Total Synthesis of (±)‐Pumiliotoxin‐C preliminary communication
Authors: Oppolzer Wolfgang , Fröstl Wolfgang , Weber Hans Peter 
Published: December 2004

AbstractDie erste Totalsynthese des racemischen Alkaloids Pumiliotoxin‐C (9) ausgehend von trans‐1‐Brom‐3‐penten (1) wird beschrieben. Die Schlüsselstufe 6 → 7 verläuft über eine intramolekulare Diels‐Alder‐Reaktion unter weitgehender sterischer Kontrolle von vier Chiralitätszentren. Die Struktur des synthetischen Produkte 9 wurde durch eine Röntgenstrukturanalyse des kristallinen Hydrogenmaleinates bestätigt.
Réctivité de dérivés des acides acétoacétique et γ‐chloroacétoacétique envers l'ion cyanure Réarrangement conduisant à de nouvelles iminopyrrolinones
Authors: Adam Jean‐Marie 
Published: December 2004

AbstractLors d'essais de substitution de l'atome de chlore du chloro‐4‐acétoacétate d'éthyle 5 et du chloro‐4‐acétoacétanilide 6 par l'ion cyanure, il a été montré que dans les conditions expérimentals décrites la substitution n'intervient en aucun cas. 5 conduit par dimérisation à la bis(éthoxycarbonyl)‐2,5‐cyclohexanedione‐1,4, 7, et 6 conduit intermédiairement à la cyanhydrine 8 qui se réarrange en Oxo‐2‐hydroxymethyl‐4‐mino‐5‐Δ3‐N‐phénylpyrroline 13 puis en Oxo‐2‐hydroxy‐méthyl‐4‐phénylimino‐5‐Δ3‐pyrroline 10. Ce réarrangement n'a pas été n' constaté dans le cas de l'acétoacétanilide 14 qui conduit, dans les mêmes conditions, intermédiairement à la cyanhydrine 15 puis à ses dérivés d'hydrolyse. Les structures chimiques ont été établies par les méthodes physiques habituelles, en particulier par 13C‐RMN., et confirmées, dans le cas des composés 13 et 10 par analyse aux rayons X.
Welkstoffe und Antibiotika. 43. Mitteilung. [1]. Fusarinonsäure und die enantiomeren Fusarinolsäuren
Authors: Büyük Füurol , Hardegger Emil 
Published: December 2004

AbstractAus 2‐Carboxy‐5‐methylpyridin (1a) wurde über das 5‐Brommethyl‐2‐methoxycarbonylpyridin (2) mit Acetessigester der Ketodicarbonsäureester 3 und daraus die Fusarinonsäure (8) hergestellt. Ein anderer Weg führte von 1a über 5‐Dibrommethyl‐2‐methoxycarbonylpyridin (5) zum 5‐Formyl‐2‐methoxycarbonylpyridin (6), welches ebenfalls zur Gewinnung der Fusarinonsäure geeignet ist. Die schon früher aus natürlicher Dehydrofusarinsäure und nun auch aus Fusarinonsäure (8) hergestellte rac. Fusarinolsäure (10a) wurde mit (+)‐und (–)‐1‐Phenyläthylamin erstmals in die optisch reinen Enantiomeren 11 & 12 zerlegt, deren absolute Konfiguration gesichert ist.
The Optical Activity of the Amide Chromophore, I. MO‐Theoretical calculation of the long‐wavelength optical activity of γ‐lactams and of related isoelectronic molecules
Authors: Geiger Rudolf E. , Wagnière Georges H. 
Published: December 2004

AbstractThe rotational strength of the longest‐wavelength electronic transition in some simple γ‐lactams and some related isoelectronic molecules is calculated using the CNDO‐CI method. Qualitative agreement with experimental values is obtained. In all investigated systems the long‐wavelength transition corresponds to the nπ* transition. A quadrant rule seems to hold for this transition.
Stereoselectivity in Reactions of Metal Complexes IV. Asymmetric Synthesis of (2R, 7S, 10R)‐ and (2R, 7R, 10R)‐2, 10‐diamino‐5, 5, 7‐trimethyl‐4, 8‐diazaundecanenickel (II) by Stereoselective Hydrogenation of (2R, 10R)‐2, 10‐diamino‐5, 5, 7‐trimethyl‐4, 8‐diaza‐7‐undecenenickel(II)
Authors: Güntert Bruno , Claude Saturnin , Bernauer Klaus 
Published: December 2004

AbstractThe catalytic hydrogenation of (2R, 10R)‐2, 10‐diamino‐5, 5, 7‐trimethyl‐4, 8‐diaza‐7‐undecenenickel(II) yields two products when the reaction is performed in the presence of ethylenediamine, but only one, when ethylenediamine is absent. The stereochemistry of the reaction is discussed and a proposal for the absolute configuration of the two diastereomeric complexes and the free ligands is given on the base of CD.‐ and NMR.‐spectra.
Alkaloide im menschlichen Gewebe 5. Mitteilung [1]. Basenkatalysierte Epimerisierung von Derivaten aus Kondensationsprodukten von L‐ und D‐Dopa mit Acetaldehyd
Authors: Bruderer Hans , Brossi Arnold , Focella Antonino , Teitel Sidney 
Published: December 2004

AbstractBase catalysed equilibration studies of optically active 2‐acetyl‐tetrahydro‐6,7‐dimethoxy‐1‐methyl‐isoquinoline carboxylic esters have been carried out, showing in all cases that the equilibrium mixtures mainly contain the trans‐isomer.
Reaktionen von Tetracyanoäthylen mit Polyenen
Authors: Pfoertner Karl‐Heinz 
Published: December 2004

AbstractReactions of tetracyanoethylene with polyenes have been studied. With vitamin A derivatives 7,10‐ and 11,14‐cycloadducts were formed. Starting with the unsaturated dihydroxy compound 13 tetracyanoethylene first catalyzed the ring closure to give the dihydrofuran 14 which then was dehydrogenated to the corresponding furan 15.
Die Phloroglucide von drei Dryopteris‐Arten von den Azoren sowie zwei Arten von Madeira und den Kanarischen Inseln zum Vergleich
Authors: Widén Carl‐Johan , Lounasmaa Mauri , Vida Gabor , Reichstein Tadeus 
Published: December 2004

AbstractThe phloroglucinols of Dryopteris aemula from the Azores and from Brittany (France), D. azorica and D. crispifolia, a new tetraploid species endemic to the Azores [8], have been investigated. The following two species recently analysed with insufficient amounts of material have been reinvestigated using improved methods: D. maderensis and ‘D. dilatata’ from Tenerife, a new species endemic to the Canary islands and described by Gibby et al. [8] as D. guanchica Gibby & Jermy. We have now found that both these species also contain much albaspidin, particularly the homologue BA. Former results for these and other species differing in some details were corrected (see Table 1) after careful re‐examination of the old chromatograms.D. aemula from all origins contains relatively large amounts of two new compounds: aemulin (1) and trisaemulin (20), the structures of which were proved by degradation, NMR.‐ and mass‐spectroscopy. Trisaemulin was present as a mixture of two homologues BBB and BAB. The latter is the first three‐ring phloroglucinol found in nature which carries an acetyl group in the middle ring. So far only butyryl‐groups were found in this position.D. azorica is diploid like D. maderensis and D. intermedia and all 3 taxa contain practically the same range of phloroglucinols. These facts are in agreement with conclusions based on morphology and cytology, which suggest that these three taxa are essentially conspecific.D. crispifolia contains the same phloroglucinols as D. dilatata s. str.; ths is a further example showing at occasionally different species produce te same compounds.‘D. dilatata’ from Tenerife differs from D. dilatata s. str. chemically not only by the absence of para‐aspidin, but also by the presence of the albaspidins‐2 and ‐3. In the same way it differs of course from D. crispifolia. This is a welcome confirmation of the morphological results [8], showing that D. crispifolia is really different from ‘D. dilatata’ from Tenerife, although it is difficult to differentiate pressed fronds of these two species.Chemical results (see Table 1) are best compatible with the assumption that D. dilatata s. str. may have had its origin from a hybrid of D. assimilis x D. maderensis (= D. azorica = D. intermedia) with subsequent doubling of its chromosomes. They also would be compatible with the possibility that D. crispifolia has arisen from D. aemula and D. azorica in a similar way, provided the latter had suppressed formation of margaspidin and aemulin present in D. aemula but absent in D. azorica and D. crispifolia. No simple rationalisation is yet possible to explain the chemical results for ‘D. dilatata’ from Tenerife with the phloroglucinols present in its putative ancestors.
Rationelle Synthese von α‐L‐Homoprolin und einiger Derivate. Herstellung von 7‐α‐L‐Homoprolin‐bradykinin
Authors: Baláspiri L. , Penke B. , Papp Gy. , Dombi Gy. , Kov´cs K. 
Published: December 2004

AbstractOptically pure α‐L‐homoproline can be prepared with good yield from N‐bnezyloxycarbonyl‐L‐proline through its diazoketone‐derivative. Preparation of derivatives of α‐L‐homoproline used in peptide chemistry, and of 7‐α‐L‐homoproline‐bradykinin, as well as biological investigation of the latter are described.
Synthese und Isolierung von Heptafulven und Sesquifulvalen
Authors: Schenk Walter Karl , Kyburz Rolf , Neuenschwander Markus 
Published: December 2004

AbstractThe synthesis and isolation of heptafulvene (1) and sesquifulvalene (2) is reported: Acetoxy‐tropylium‐fluoroborate (10) may be prepared by addition of tropone to acetyl‐fluoroborate at low temperatures. The tropylium salt reacts easily with methyllithium and sodium cyclopentadienide to give the acetoxy‐methyl‐cycloheptatrienes 11 and the acetoxy‐cyclopentadienyl‐cycloheptatrienes 12 respectively. Gas‐phase pyrolysis of 11 and 12 affords in remarkably good yields heptafulvene (1) and sesquifulvalene (2), which are isolated in cristalline form at low temperatures. Spectroscopic as well as chemical evidence of the title compounds is presented.
Gasphasenkomplexe zwischen Kobaltchlorid und Aluminiumchlorid
Authors: Dell'Anna A. , Emmenegger F. P. 
Published: December 2004

AbstractCoCl2 forms two gaseous complexes in the presence of gaseous Aluminiumchlorid:
equation image
The equilibria were investigated by dynamic vapour pressure measurements (transpiration and chemical transport), by optical spectroscopy and by quenching the equilibrium gasphase followed by analysis of the condensates. The chromophor in the gaseous complexes appears to be tetrahedral CoCl4.
Dérivés C‐glycosyliques XXIII. Radicaux libres stables dérivés de sucre Communication préliminaire
Authors: Tronchet Jean M. J. , Mihaly Eva , Geoffroy Michel 
Published: December 2004

AbstractTreated with 2,3‐dimethyl‐2,3‐bis‐(hydroxylamino)‐butane, aldehydo‐dialdofuranoses (1) gave a mixture of two compounds: a 1,3‐dihydroxyimidazolidine (2) and a 1‐hydroxyimidazoline (3). Oxidation (PbO2) of compounds 3 gave stable free radicals having the structure of 2‐C‐Glycosyl‐4,4,5,5‐tetramethylimidazolines 1‐oxyl (4), whereas 2‐C‐Glycosyl‐4,4,5,5‐tetramethylimidazolines 3‐oxide 1‐oxyl (5) were formed by oxidation of 2. The ESR. spectra of compounds 4 and 5 establish the structure of the imidazoline part of these radicals and provide informations on the sugar moiety.
Neuartige Merocyanine vom Typ des «Bindons»
Authors: Schelz Dieter 
Published: December 2004

AbstractThe title compounds (new type of merocyanines) were obtained from the reaction of heterocyclic enamines with indan‐1,3‐dione, biindantrione, 2‐(3‐methoxy‐inden‐1‐yliden)‐indan‐1, 3‐dione, or 2‐(3‐chloro‐inden‐1‐yliden)‐indan‐1, 3‐dione respectively. The enamines were obtained from the corresponding quaternary salts and reacted in situ.
Thermodynamik der Metallkomplexbildung mit Polyoxadiazamacrocyclen
Authors: Anderegg Giorgio 
Published: December 2004

AbstractLigands of the type H3‐nN(CH2CH2OCH2CH2OCH2CH2)nNH3−n with n values from 1 to 3 have been investigated. The stability constants and the heat evolved by formation of the 1:1 complexes of Na+, K+, Rb+, Tl+, Ca2+, Sr2+, Ba2+, Cd2+, Ag+, Hg2+ and Pb2+ have been determined. The complex formation is discussed in terms of ΔH and ΔS taking into consideration the radii of the cations. In contrast with the normal trend, for the A cations, complex formation is exothermic and almost exclusively favoured by the reaction enthalpy.
Cheletrope Reaktion vinyloger Enollactone
Authors: Skorianetz Werner , Ohloff Günther 
Published: December 2004

AbstractGasphase thermolysis above 220° of 2(3H)‐oxepinones 2 and 2(3H)‐furanones 5 gives carbon monoxide and the corresponding unsaturated carbonyl compounds 3, 4 and 6. The preparative value of these cheletropic processes is demonstrated.
«Nα/Nβ‐Isomerie» bei äquatorial koordinierten 1:2‐Co(III)‐Komplexen aus 2‐Hydroxy‐6‐methylphenyl‐1,1′‐azonaphtolen‐(2′)
Authors: Steiner Eginhard , Schetty Guido 
Published: December 2004

AbstractAn o, o′‐Dihydroxyphenylazomethin und‐azofarbstoffen, welche im Phenylrest eine zur Azomethin‐ bzw. Azogruppe o‐ständige Methylgruppe besitzen, wurden die Unterschiede der CH3‐Protonensignale im 1H‐NMR.‐Spektrum beim Übergang der Liganden zu den 1:2‐Co(III)‐Komplexen untersucht. Die beobachteten Regelmässigkeiten unterstützen und ergänzen die in [1] gemachten Feststellungen.Ausserdem wird durch die Einführung der CH3‐Gruppe in die genannte Stellung bei «Phenylazo‐2‐naphthol‐Komplexen» eine «Nα/Nβ‐Isomerie» induziert, die bei Abwesenheit dieser CH3‐Gruppe nicht auftritt.Dieses Ergebnis ist ein Hinweis dafür, dass grundsätzlich jedem o, o′‐Dihydroxyazofarbstoff diese Isomeriefähigkeit inhärent ist.
Réactivité des silyl‐ et germylphosphines vis‐à‐vis de divers composés à insaturation CN: imines, α‐diimines, N‐acylimines et cétènimines
Authors: Couret Claude , Couret Françoise , Satgé Jacques , Escudié Jean 
Published: December 2004

AbstractSilylphosphines R3SiPR′2 add on the CN group of aldimines yielding phosphinylated silylamines of the structure . Hydrolysis of these adducts leads to the corresponding substituted aminomethyl‐phosphines.In the reaction between α‐diimines and silylphosphines or silyldiphosphines R2Si(PR′2)2 the acyclic 1/1 and ½ addition compounds have been characterized. The adduct 1/1 obtained by the action of diethyl‐hydrodimethylsilyl‐phosphine on di‐tert‐butylimino‐ethane undergoes in the presence of Wilkinson's catalyst, (Ph3P)3RhCl, an intramolecular Si‐H/CN cyclisation leading to a phosphinylated siladiazolidine.Silylphosphines add to N‐acylimines in 1,4 position to form phosphinylated siloxyimines. The methanolysis of the latter derivatives is an novel method of preparation of phosphinylated amides.Silyl‐ and germylphosphines react on the CN groupement of cetimines. The hydrolysis of the adducts (N‐metallated enamines) leads to C‐phosphinylated imines.
Heteronuklear überbrückte tricyclische Systeme. Oxa‐brexane‐ und ‐brendane
Authors: Fritz Hans , Weis Claus D. , Winkler Tammo 
Published: December 2004

AbstractUnsaturated cyclic and bicyclic hydrocarbons react with chloral in presence of aluminium chloride to yield tricyclic oxabrexanes which undergo acid catalyzed rearrangements to oxabrendanes. 1,5‐cyclooctadiene gives the new oxa‐cyclo[c, d]octahydropentalen. Structural evaluations and stereochemical assignments are discussed on the basis of detailed 1H‐ and 13C‐NMR.‐spectra.
Beitrag zur Partialsynthese 18‐oxygenierter Cortexone I. Synthese von 18‐Hydroxy‐cortexon Über Steroide, 230. Mitteilung
Authors: Biollaz Michel , Kalvoda Jaroslav , Schmidlin Julius 
Published: December 2004

AbstractTwo improved procedures for the synthesis of 18‐hydroxycortexone and derivatives thereof are presented. One approach involved the development of an efficient method for preparing cyclic 20‐enol ethers as key intermediates for the oxygenation at position 21. In an alternative sequence, starting from a 21‐hydroxypregnene compound, 18‐functionalization has been achieved as the final step by hypoiodite reaction.
Beitrag zur Partialsynthese 18‐oxygenierter Cortexone II. Synthese von 18‐Oxo‐cortexon Über Steroide 231. Mitteilung
Authors: Biollaz Michel , Schmidlin Julius , Kalvoda Jaroslav 
Published: December 2004

Abstract18‐Oxocortexone, a potential metabolite of 11‐deoxy‐corticosterone and precursor of aldosterone has been synthesized, starting from 3β‐hydroxy‐5‐pregnene‐20‐one acetate via subsequent functionalization at positions 18 and 21.
Herstellung von DL‐N‐Benzyloxycarbonyl‐γ‐carboxy‐glutamin‐säure‐γ,γ′‐di‐t‐butyl‐α‐methyl‐ester, einem für die Peptidsynthese geeigneten Derivat der neuen Aminotricarbonsäure aus Prothrombin
Authors: Märki Walter , Schwyzer Robert 
Published: December 2004

AbstractThe first synthesis of a selectively, fully protected derivative of the new aminotricarboxylic acid found in prothrombin and other homologous blood‐clotting factors, γ‐carboxy‐glutamic acid (Gla), is described. The compound DL‐N‐benzyloxycarbonyl‐γ‐carboxy‐glutamic acid γ,γ′‐di‐t‐butyl‐γ‐methyl‐ester is potentially useful for peptide synthesis. The free amino‐acid (DL‐Gla) and DL‐pyro‐γ‐carboxy‐glutamic acid dimethyl‐ester were also prepared.
2,3,5,6‐Tetramethylidene‐Bicyclo[2.2.1]Heptane (Preliminary Communication)
Authors: Florey André , Vogel Pierre 
Published: December 2004

AbstractPreparation of the title compound 1 is described. An important transannular effect between the two unconjugated s‐cis‐butadiene chromophores is observed by comparison of the UV. spectra of the tetramethylidenenorbornane 1 and the dimethylidenenorbornane 3. The differences observed between the UV. spectra of 2,3,5,6‐tetramethylidene‐7‐oxanorbornane 2 and 1 are also discussed briefly.
Reactions with benzo[b]thiophene‐2,3‐diones I: Synthesis of 2,3‐dihydroxy‐2,3‐diaryl(aralkyl)benzo[b]thiophene derivatives
Authors: Sallam Mohamed Mohamed Mohamed , Elnagdi Mohamed Helmi , Abdel‐Hady Mohamed Husein 
Published: December 2004

AbstractBenzo[b]thiophene‐2,3‐diones (1) react with Grignard reagents to yield 2,3‐dihydroxy‐2,3‐diaryl(aralkyl)benzo[b]‐thiophenes (2). The latter compounds yield 3,3‐diaryl(aralkyl)‐benzo[b]thiophene‐2‐ones (3) by pinacolone rearrangement. Treatment of 3 by hot ethanolic sodium hydroxide solution yields the corresponding carboxylic acids by hydrolytic heteroring opening.