bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chirale Alkoxytitan(IV)‐Komplexe für enantioselektive nucleophile Additionen an Aldehyde und als Lewis‐Säuren in Diels‐Alder‐Reaktionen
Authors: Seebach Dieter , Beck Albert K. , Imwinkelzied René , Roggo Silvio , Wonnacott Anne 
Published: December 2004

Chiral Alkoxytitanium(iv) Complexes for Enantioselective Nucleophilic Additions to Aldehydes and as Lewis Acids in Diels‐Alder ReactionsA Number of chiral 1,2‐1,3 and 1,4‐diols were prepared and used as alkoxy ligands on Ti for enantioselective nucleophilic transfer of methyl, butyl, cyclopropyl, allyl, alkinyl, and phenyl groups to aromatic aldehydes, as well as for the enantioselective[4+2]cycloaddition of acrylate to cyclopentadiene. The 1,2‐diols were pinane diol 7 and 1,2:5.6‐diacetonide‐protected mannitol 9 (Scheme 3) and tartrates. The 1,3‐diols were obtained from the yeast‐reduction products of 2‐oxocyclopentane‐ and 2‐oxocyclohexanecarboxylates and excess MeLi, BuLi, or PhLi (or the corresponding Grignard reagents; see4–6.) As 1,4‐diols, we used the products 2 and 3 from tartrate acetals and methyl or Pheny1 Grignard reagents, the bis(benzaldehyde) acetal 8 of d‐mannitol and o,o'‐binaphthol (22). These diols were attached to the Ti‐atom by azeotropic removal of i‐PrOH from a mixture with [TiCi(i‐PrO)3]. Addition of various organometallic reagents R‐metal (metal = Li, BR3, MgX, MnC1, CuLiR) was followed by combination with aldehydes at – 75., a warm up period, quenching with aqueous KF solution, and workup (for results see Tables 1–6 and Formulae 17–20). The enantiomeric excess of the secondary alcohols obtained varies greatly, certain combinations of chiral ligands, nucleophilic groups, and aldehyde substrates give rise to values as high as 90% ee; see e.g. Table 4. The Ti‐complexes of the general formula [Ti(R*O)2Ci2] or [Ti(R*O)2(i‐PrO)CI] induced the Diels‐Alder addition of methyl acrylate to cyclopentadience to take place at –30.. The best enantioselectivity (50% ee) was observed with the binaphthol derivative (Table 7). The structures of the complexes involved in these reactions are unknown. The substitution on C(2) of the dioxolanes 2 and 3 (derived from tartaric acid) has a pronounced effect on the selectivities of both reactions studied here (Tables 2, 3, and 7). This remote effect (1,6‐distance between the stereogenic acetal‐C‐atom and the Ti‐centers) must be caused by conformational changes in the vicinity of the reactive site, i.e. the TiC bond in the nucleophilic addition reactions and the Ti‐acrylate‐oxygen complexation in the Diels‐Alder reaction.
Bildung tricyclischer Thietan‐Derivate durch intramolekulare(2+2)‐Cycloaddition
Authors: Wipf Peter , Heimgartner Heinz 
Published: December 2004

Formation of Thietane Derivatives via Intramolecular (2+2) CycloadditionOn irradiation, the two 4‐vinyl‐1,3‐thiazole‐5(4H)‐thiones 1a, b, synthesized from thiobenzoic acid and the corresponding 3‐amino‐2H‐azirines 2a,b, undergo an intramolecular (2+2)‐cycloaddition reaction of the CS and CC bonds to give the tricyclic thietane derivatives 3a,b.
Photochemical Synthesis of 2‐Alkylidene‐1,3‐cyclocalkanediones. Preliminary Communication
Authors: Hobel Klaus , Margaretha Paul 
Published: December 2004

AbstractPhotolysis (λ = 254 nm) of 4‐(tert‐butyl)‐4,6,7,8‐tetrahydro‐7,7‐dimethy‐2H‐1‐benzopyran‐2,5(3H)‐dione (3a) in t‐BuOH affords 2‐(2,2‐dimethylpropylidene)‐5,5‐dimethyl‐1,3‐cyclohexanedione (1a) in 80% yield via homolysis of the lactone OCO bond and subsequent ketene elimination.
Oxidationsreaktionen methyl‐substituierter 2,1,3‐Benzothiadiazole und 2,1,3‐Benzoselenadiazole mit Selen‐dioxid
Authors: Neidlein Richard , Knecht Dagmar 
Published: December 2004

Oxidation Reactions of Methyl Substituted 2,1,3‐Benzothiadiazoles and 2,1,3‐Benzoselenadiazoles with Selenium DioxideThe synthesis 5–8 by oxidation of 4‐methyl‐(1),5‐methyl(2), 5,6‐dimethyl‐2,1,3‐benzoselenadiazole (3), and 5,6‐dimethyl‐2,1,3‐benzothiadiazole (4), respectively, with selenium dioxide as well as their spectroscopic properties are described.
Control of Diels‐Alder Addition, Stereo‐ and Regioselectivity by Remote Substituents and Tricarbonyl(diene)iron Moieties
Authors: Zwick Jean‐Christophe , Voge Pierre , Mange Vladimir , Chapuis Gervals 
Published: December 2004

AbstractA stereoselective synthesis of tricarbonyl‐[((1RS,2RS,4RS,5RS,6RS)‐C‐5,6,C‐η‐(5,6,7,8,‐tetramethylidenbicyclo[2.2.2]octan‐2‐ol)]iron (11),and of its tosylate 12 and benzoate 13 is reported. The bulk of the ‘endo’‐Fe(CO))3 moiety and of the ester groups in 13 renders its Diels‐Alder additions to methyl propynoate (15)), butynone (16), and 1‐cyanovinyl acetate highly ‘para’ regioselective. The cycloadditions of diene‐alcohol 11 are either ‘meta’‐ or ‘para’‐regioselective depending on the nature of the dienophile. In the presence of BF3. Et2O, the addition of 11 to methyl vinyl ketone is highly stereo‐ (Alder mode) and ‘para’‐regioselective, giving adduct 52 (tricarbonyl [((1 RS,4RS,8RS,9RS,10RS,12RS)‐C,9,10,C‐η‐(12‐hydroxy‐9,10‐dimethylidenetricyclo[6.2.2.02,7]dodec‐2(7)‐en‐4 yl methyl ketone)]iron) whose structure has been established by single‐crystal X‐ray crystallography.
Synthèse d'homologues de la (–)‐‐(1R,2S)‐norephedrine
Authors: Lamant Maurice , Guignard Alain 
Published: December 2004

Synthesis of (–)‐(1R,2S)‐Norephedrine HomologuesThe amino function of esters of some simple natural amino acids I is blocked in the form of a cyanoenamine by means of 2‐oxocyclopentanecarbonitrile, so that the corresponding cyanoenamino esters II are obtained. The reaction of a disubstituted lithium amide with II leeds to the cyanoenamino‐amides VI. The amide function present in VI is then transformed into an aromatic ketone by means of phenyllithium, to give the (benzoylalkyl)aminocyclopentenecarbonitriles VII. Reduction of Compounds VII with NaBH4 in EtOH −80° affects only the keto function and leads to the [(α‐hydroxybenzyl)alkyl]amino‐cyclopentenecarbonitriles VIII. The amino function is then deprotected by acid hydrolysis to give the amino‐alcohols IX with yields close to 50%; in every amino‐alcohol IX, the erythro isomer, homologous to natural (–)‐(1R,2S)‐norephedrine is the more abundant or the single product. All the polyfunctional compounds prepared conserve optical activity; it has been demonstrated that the amino‐alcohols IX are pure enantiomers and that no racemisation lakes place at any step of their synthesis.
Structures and Mutagenic Properties of Products Obtained by C‐Nitrosation of Opipramol
Authors: Faigle Johann W. , Blattner Hans , Glatt Hansruedi , Kriemler Hans‐Peter , Mory Hans , Storni Angelo , Winkler Tammo , Oesch Franz 
Published: December 2004

AbstractReaction of the tricyclic psychotropic drug opipramol (1) with an excess of HNO2 affords a product mixture mutagenic for Salmonella typhimurium. The main product is a tetracyclic furoxan 2 (yield ca. 80%), resulting from nitrosation at C(10) and C(11) of 1. Compound 2 is not mutagenic. The essential mutagen is a nitroarene 3 formed via contraction of the central ring of 1, and nitrosation at C(2). Its yield is extremely low (<0.1%). Nitroarenes have previously not been encountered as mutagenic products of the interaction of drugs with nitrite.
Short Syntheses of (±)‐Grandisol and (±) Lineatin via, a common Intermediate
Authors: Aljancic‐Solaja Ivana , Rey Max , Dreiding André S. 
Published: December 2004

AbstractA 6‐step synthesis of (±)‐grandisol (1) is presented, which involves dichloroketene addition to 3‐methyl‐3‐butenyl acetate (4), reductive dechlorination of the adduct 6 to the ketone 7 and saponification to 8, aldolization of 7 or 8 with acetone and cyclization to the bicyclic ketone 9, Wolff‐kishner, reduction to 14, and finally ring opening to 1. Since 9 is a known intermediate of the synthesis of (±)‐lineatin (2), the latter can now be obtained in 6 steps.
Herstellung enantiomerenreiner Derivate von 3‐Amino‐ und 3‐Mercaptobuttersäure durch SN2‐Ringöffnung des β‐Lactons und eines 1,3‐Dixoanons aus der 3‐Hydroxybuttersä ure
Authors: Griesbeck Axel , Seebach Dieter 
Published: December 2004

Preparation of Enantiomerically Pure Derivatives of 3‐Amino‐ and 3‐Mercaptobutanoic Acid by SN2 Ring Opening of the β‐Lactone and a 1,3‐Dioxanone Derived from 3‐Hydroxybutanoic AcidFrom (S)‐4‐methyloxetan‐2‐one (1), the β‐butyrolactone readily available from the biopolymer (R)‐polyhydroxybutyrate (PHB) and various C, N, O and S nucleophiles, the following compounds are prepared:(s)‐2‐hydroxy‐4‐octanone (3), (R)‐3‐aminobutanoic acid (7) and its N‐benzyl derivative 5, (R)‐3‐azidobutanoic acid (6) (R)‐3‐mercaptobutanoic acid (10), (R)‐3‐(phenylthio)butanoic acid (8) and its sulfoxide 9. The (6R)‐2,6‐dimethyl‐2‐ethoxy‐1,3‐dioxan‐4‐one (4) from (R)‐3‐hydroxybutanoic acid undergoes SN2 ring opening with benzylamine to give the N‐benzyl derivative (ent‐5) of (S)‐3‐aminobutanoic acid in 30‒40% yield.
Asymmetric Dihydroxylations of β‐Substituted N‐(α,β‐Enoyl)bornane‐10,2‐sultams
Authors: Oppolzer Wolfgang , Barras Jean‐Pierre 
Published: December 2004

AbstractPure (E)‐ or (Z)‐enoylsultams 2 were Oxidized with OsO4/N‐Methylmorpholine N‐oxide in a stereospecific and highly π‐face‐selective manner. Acetalization of the resulting 1,2‐diols furnished, after purification, the stable, crystalline acetals 6 in >99% d.e. and in 63–74% overall yield from 2. Reductive or hydrolytic cleavage of 6 gave enantiomerically pure alcohols 8 or carboxylic acids 9 with recovery of the sultan auxiliary 1.
Synthese von N‐Methyl‐ und N,N‐Dimethylmerucathin sowie von N‐Methyl‐ und N,N‐Dimethylpseudomerucathin aus L‐Alanin
Authors: Stoll Hanspeter , Wolf Jean‐Pierre , Pfander Hanspeter 
Published: December 2004

Synthesis of N‐Methyl‐ and N,N‐Dimethylmerucathine and of N‐Methyl‐ and N,N‐‐Dimethylpseudomerucathine Starting from L‐AlanineStarting form L‐alanine, N‐methylmerucathine (= (3R,4S)‐4‐(methylamino)1‐phenyl‐1‐penten‐3‐ol; (3R,4S,)‐6), N,N‐dimethylmerucathine (= (3R,4S)‐4‐(dimethylamino)‐1‐phenyl‐1‐penten‐3‐ol; (3R,4S)‐9), N‐methylpseudomerucathine (= (3S,4S)‐4‐(methylamino)‐1‐phenyl‐1‐penten‐3‐01; (3S,4S)‐6), and N,N‐dimethylpseudomerucathine (= (3S,4S)‐4‐(dimethylamino)‐1‐phenyl‐1‐penten‐3‐ol; (3S,4S)‐9) were synthesized. The four compounds were analyzed by HPLC and compared with a natural khat extract.
Synthesis of 1‐Fluoro‐2‐amino‐1,3‐cyclohexadienes and 1‐Fluorobicyclo[2.2.2]octan‐2‐ones
Authors: Pick‐Schliebs Heike , Margaretha Paul 
Published: December 2004

AbstractConjugated β‐fluoro‐enamines 4 undergo cycloaddtion to methyl acrylate regio‐ and stereospecifically, affording the 1‐fluorobicyclo[2.2.2]octan‐2‐one 6a after hydrolysis.
β‐Cleavage of Bis(homoallylic) Potassium Alkoxides. Two‐Step Preparation of Propenyl Ketones from Carboxylic Esters. Synthesis of ar‐Turmerone, α‐Damascone, β‐Damascone, and β‐Damascenone
Authors: Snowden Roger L. , Linder Simon M. , Muller Bernard L. , Schulte‐Elte Karl H. 
Published: December 2004

AbstractThe transformation of 36 bis(homoallylic) alcohols VII to alkenones IX and X via β‐cleavage of their potassium alkoxides VIIa in HMPA has been investigated (cf. Scheme 2). These studies have established an order of β‐cleavage for 2‐propenyl, 1‐methyl‐2propenyl, 2‐methyl‐2‐propenyl, 1,1‐dimethyl‐2propenyl, and benzyl groups in alkoxides 49a–56a and have allowed a comparison between the β‐cleavege reaction and the oxy‐Cope rearrangement in alkoxides 74a–83a. As illustrative syntheti applications, a two‐step preparatio of propenyl ketones 15–42 from carboxylic esters is described, together with syntheses of ar‐turmerone (48), α‐damascone ((E)‐71), β‐damascone ((E)‐109), and β‐damascenone ((E)‐111).
Formation and Structure of the Phosphoranyl Radical Derived from 1,2‐Phenylene Phosphorochloridate: a Solid‐State ESR Study
Authors: Cattani‐Lorente Maria , Bernardinelli Gérald , Geoffroy Michel 
Published: December 2004

AbstractThe crystal structure of 1,2‐ phenylene phosphorochloridate has been determined. X‐Ray irradiation of these crystals, at low temperature, leads to the formation of a radical exhibiting hyperfine structure with P and Cl nuclei. The corresponding ESR tensors are obtained, and they show that this radical is a phosphoranyl radical adopting a slightly distorded σ* structure. The same species could be produced in frozen solution, its hyperfine tensors are, then, more in accordance with a trigonal‐bipyramid structure. The effects of the host matrix on the stabilization of the structure of phosphoranyl are investigated.
Isolierung und Strukturaufklärung von 36 Diterpenoiden aus Trichomen von Plectranthus edulis (VATKE) T.T. AYE
Authors: Künzle Josef Max , Rüedi Peter , Eugster Conrad Hans 
Published: December 2004

Isolation and Structure Elucidation of 36 Diterpenoids from Leaf‐Glands of Plectranthus edulis (VATKE) T.T. AYEAnalysis of the polar diterpenoids from the yellow glands of the title plant from Kenya and Abyssinia led to the identification of several novel abietanoids. Main compound is the known edulon A (40), a 5(4→3) abeo‐abietane. Minor compounds include 6 different royleanones, 15 spirocoleons, 3 vinylogous quinones, 8 acylhydroquinones (as their 6,7‐dioxo compounds or the tautomeric disophenols), 2 naphthaquinones (as the 1,10‐seco‐abietanoids), and deacetyledulon A. The known coleon‐A‐lactone (37) now has also been found in Plectranthus edulis. The intermediacy of the γ‐enollactol 44, combined with a leaving group on C(3) is postulted to explain the biogenesis of the unusual 4H‐5‐oxaaceanthrylen skeleton of edulon A.
Synthesis of trans‐10,11‐Dihydro‐10,11‐dihydroxy‐5H‐dibenz[b,f]azepine‐5‐carboxamide, a Major Metabolite of Carbamazepine
Authors: Heckendorn Roland 
Published: December 2004

AbstractThe stereoselectivity of the reduction of 5‐carbamoyl‐10,11‐dihydro‐11‐oxo‐5H‐dibenz[b,f]azepine‐10‐yl acetate (6), prepared in two steps from 10,11‐dihydro‐10‐oxo‐5H‐dibenz[b,f]azepine‐5‐carboxamide (4), has been studied. Among the reagents used, diisobutylaluminum hydride (DIBAH) was found to give the highest trans/cis diol ratio. This allowed the preparation of the important trans‐diol metabolite 3 of carbamazepine (1).
The Aluminum‐Bromide‐Catalyzed Adamantane Rearrangement of syn‐ and anti‐Tricyclo[4.2.1.12,5]decane
Authors: Brossi Marco , Ganter Camille 
Published: December 2004

AbstractIn the presence of AlBr3 in CS2 at temperatures below 0°, syn‐tricyclo[4.2.1.12,5]decane (1) isomerizes exclusively to anti‐tricyclo[4.2.1.12,5]decane (2) at a higher rate than the latter rearranges to 2‐exo,3‐exo‐trimethylene‐8,9,10‐trinorbornane (4). However, at temperature above 0°, the anti‐isomer 2 isomerizes to 4 faster than 1 to 2 and 4. As a consequence, hydride abstraction occurs at C(3) (→carbocation a, which rearranges to carbocation b (anti‐skeleton)) in the syn‐isomer 1, and more readily at C(9) (→carbocation c) than at C(3) (→carbocation b) in the anti‐isomer 2.
10′‐Apolycopin‐10′‐ol und 10′‐Apolycopin‐10′‐säure aus Blüten der Rosenhybride ‘Maréchal Niel’. 6. Mitteilung über Farbstoffe aus Rosen
Authors: Märki‐Fischer Edith , Uebelhart Peter , Eugster Conrad Hans 
Published: December 2004

10′‐Apolycopen‐10′‐ol and 10′‐Apolycopen‐10′‐oic Acid from the Petals of the Rose Hybrid ‘Maréchal Niel’The novel 10′‐apolycopen‐10′‐ol (1) and 10′‐apolycopen‐10′‐oic acid (4) were isolated from the yellow petals of the once world‐renowned rose hybrid ‘Maréchal Niel’. The relative amount of either 1 or 4 produced by the plant depends upon the climatic conditions. Both 1 and 4 together with related compounds were synthetisized and characterized by spectral data.
Functionalisation of saturated hydrocarbons. Part XI. Oxidation of cedrol, β‐ and γ‐eudesmol, sclareol, manoyl oxide, 1,9‐dideoxyforskolin, methyl trans‐dihydroiasmonate, and tetrahydrolinalool by the ‘Gif system’
Authors: Barton Derek H. R. , Beloeil Jean‐Clauude , Billion Annick , Boivin Jean , Lallemand Jean‐Yves , Lelandais Patrick , Mergui Simone 
Published: December 2004

AbstractThe oxidation of cedrol (1), β‐ and γ‐eudesmol (6 and 7, resp.), sclareol (14) manoyl oxide (15), 1,9‐dideoxyforskolin (22) (±)‐methyl trans‐dihydrojasmonate (28), and tetrahydrolinalool (32) nearly all of natural terpenoid origin, by the ‘Gif system’ has afforded a number of novel products (3, 11, and 12, 16/17, 18/19, 26, 29–31, and ketones corresponding to 34–35, res.). The structures of these compounds were established by spectroscopic techniques including 2D‐NMR and, where appropriate, by comparison with authentic samples.
Halochrome Molekeln. 7. Mitteilung. Synthese und acidobasisches Verhalten substituierter Heteroarenochinazoline
Authors: Gunzenhauser Sigmund , Balli Heinz 
Published: December 2004

Halochromic Molecules. Synthesis and Acidobasic Properties of Substituted HeteroarenoquinazolinesWe have synthetized a series of substituted heteroarenoquinazolines. The 90‐MHz FT 1H‐NMR spectra of starting and final products supported the postulated structures. Fragmentation in the mass spectra also were consistant with the assumed structures. With acid, the compounds partly from ring‐opened, intensely coloured triphenylcarbenium salts of the Rhoduline‐R type (C. I. 42565). UV/VIS spectra of the salts are discussed on the basis of VEPPP‐CI calculations. The ϵpH* curves in buffered MeOH/H2O solutions and the pK* values are determined. The title compounds undergo very complex protonation equilibria.
Metal Complexes with Macrocyclic Ligands. Part XXVI. Synthesis and spectral properties of Cu2+ complexes with mono‐N‐functionalized 1,4,8‐trimethyl‐1,4,8,11‐tetraazacyclotetradecanes
Authors: Tschudin Daniel , Basak Arup , Kaden Thomas A. 
Published: December 2004

AbstractA series of mono‐N‐functionalized 1,4,8‐trimethyl‐1,4,8,11‐tetraazacyclotetradecanes 3–14 were synthesized by alkylating the secondary N‐atom of the macrocycle 1. The spectral properties of the Cu2+ complexes, studied under different pH conditions, are discussed in relation to the possibility of coordination of the donor group of the side chain to the axial position of the metal ion and to the effect of the length of the side chain.
Silicon‐Directed Nazarov Cyclizations. Part V. Substituent and heteroatom effects on the reaction
Authors: Denmark Scott E. , Habermas Karl L. , Hite Gary A. 
Published: December 2004

AbstractThe ability to incorporate alkyl, alkenyl, aryl, and heteroatomic groups into substrates for the silicon‐directed Nazarov cyclization and their subsequent reactions has been investigated. In general, most of the groups are compatible with the conditions for the cyclization and do not interfere even when directly attached to the divinyl ketone. The influence of substituents on the rate of the cyclization has been addressed and is consistent with a simple mechanistic picture. O‐ and N‐Containing functions are tolerated except when attached to the α‐vinyl C‐atom of the divinyl ketone. The diastereoface‐directing effect of a fused cyclobutane is discussed.
Konformationsanalysen von Modell‐Tripeptiden: Der Einfluss von α,α‐disubstituierten α‐Aminosäuren auf die Sekundärstruktur. Teil I. NMR‐ und CD‐Untersuchungen
Authors: Wipf Peter , Heimgartner Heinz 
Published: December 2004

Conformational Analysis of Tripeptide Models: The Influence of α,α‐disubstituted α‐Amino Acids on the Secondary Structure. NMR and CD InvestigationsThe conformational properties of α,α‐disubstituted α‐amino acids are discussed on the basis of NMR, CD, X‐ray, and molecular‐mechanics studies on tripeptide models 1. It is shown that different disubstituted amino acids do not exert the same influence on secondary‐structure formation. Thus, the choice of substituents allows the construction and stabilisation of different conformations of oligopeptide chains.
Synthese von (−)‐(R)‐Nephthenol und (−)‐(R)‐Cembren A
Authors: Schwabe Rudolf , Farkas Imre , Pfander Hanspeter 
Published: December 2004

Synthesis of (−)‐(R)‐Nephthenol and (−)‐(R)‐Cembren AStarting for L‐serine,(−)‐(R)‐nephthenol((−)‐2) and (−)‐(R)‐cembren A((−)‐3) were synthesized.
[4 + 2]‐Cycloadditionen von α,β‐ungesättigten Hydrazonen. Teil 1. Pyridin‐2,3‐dicarboximide aus 1‐(Dimethylamino)‐1,4‐dihydropyridin‐Derivaten
Authors: Waldner Adrian 
Published: December 2004

[4 + 2] Cycloadditions of α,β‐Unsaturated Hydrazones to Pyridine‐2,3‐dicarboximides via 1‐(Dimethylamino)‐1,4‐dihydropyridine DerivativesThe [4 + 2] Cycloaddition of α,β‐unsaturated hydrazones of type 1 (1‐aza‐1,3‐butadienes) with 2‐halogenomaleimides 4 affords 1,4‐dihydropyridines 6 which, after treatment with an acid, yield highly substituted pyridine‐2,3‐dicarboximide derivatives 7 (Scheme 1).
Sambucinic Acid, a New Metabolite of Fusarium sambacinum. 45th communication on verrucarins and roridins
Authors: Rösslein Lukas , Tamm Christoph , Zücher Werner , Riesen Andreas , Zehnder Margareta 
Published: December 2004

AbstractSambucinic acid (5), a C15‐trichothecene with a modified strure, has been isolated from cultures of Fusarium sambucinum. The structure is established by spectroscopic data and X‐ray diffraction analysis. A hypothetical biogenetic pathway is proposed.
Alkylation of Adenine, Adenosine, and NAD+with 1,3‐Propanesultone. Synthesis ofN6‐(3‐sulfonatopropyl)‐NAD+, a new NAD+derivative with substantial coenzyme activity
Authors: Carrea Gianconno , Ottolina Gianluca , Riva Sergio , Danieli Bruno , Lesma Giordano , Palmisano Giovanni 
Published: December 2004

AbstractThe reactivity of 1,3‐propanesultone with adenine, adenosine, and NAD+was studied in order to prepareN6‐(3‐sulfonatopropyl)‐NAD+(3b), a new NAD+derivative substituted at the purine moiety with sunstantial coanzyme activity for several dehydrogenases. The regiochemistry of the alkylation at the purione nucleus was investigated by UV,1H‐NMR, and FAB‐MS proved to be a powerful tool for determining the molecular weight of these polar and poorly volatile compounds. In addition, regular framgmentation of3band other NAD+derivatives was observed.
Identifizierung von 2‐Acetamido‐2‐desoxy‐α‐D‐glucopyranosyl‐1‐phosphat in Kuhmilch als Wachstumsfaktor für Treponema vincentii
Authors: Bernet Bruno , Wyss Christoph 
Published: December 2004

Identification of 2‐Acetamido‐2‐deoxy‐α‐D‐glucopyranosyl 1‐Phosphate in Cow‐Milk as Growth Factor for Treponema vincentiiA 7:3 mixture of 2‐acetamido‐2‐deoxy‐α‐D‐glucopyranosyl and ‐α‐D‐galactopyranosyl 1‐phosphate (1 and 2, resp.) was isolated from cow‐milk and identified by 1H‐ and 13C‐NMR spectroscopy. The 2‐acetamido‐2‐deoxy‐α‐D‐glucopyranosyl 1‐phosphate is a growth factor for Treponema vincentii.
Intramolecular Dynamics of Tetranuclear Iridium Carbonyl Cluster Compounds. Part 1. Bromotri‐μ‐carbonyloctacarbonyltetrairidate(1–)
Authors: Strawczynski Andrés , Ros Renzo , Roulet Raymond 
Published: December 2004

AbstractA 2D and variable‐temperature 13C‐NMR study indicates that a CO‐site exchange occurs in the title complex via several consecutive processes, the first being a ‘merry‐go‐round’ of the basal CO's, the second a switch of basal face not involving unbridged intermediates.
Metabolism of carotenoids in salmonids. Part 2. Distribution and absolute configuration of idoxanthin in various organs and tissues of one atlantic salmon (Salmo salar, L.) fed with astaxanthin
Authors: Schiedt Katharina , Mayer Hans , Vecchi Max , Glinz Ernst , Storebakken Trond 
Published: December 2004

AbstractThe content of total carotenoids and the ratio astaxanthin/idoxanthin ( = 3,3′‐dihydroxy‐β,β‐carotene‐4,4′‐dione/3,3′,4′‐trihydroxy‐β,β‐caroten‐4‐one) in varoius organs and tissues of one Atlantic salmon (Salmo salar, L.) reared indoors in a tank were analyzed after feeding ‘racemic’ ((3R,3′R)/(3R,3′S; meso)/(3S,3′S) 1:2:) astaxanthin (90 mg/kg feed) during one yera. Configurational analysis of astaxanthin was carried out via the (−)‐dicamphanate derivative and that of idoxanthin after reaction with (+)‐(S)‐l‐(l‐naphthyl)ethyl isocyanate. Separation of all eight optical isomers of idoxanthin‐tricarbamate derivatives by HPLC is described. In salmon, enzymatic reduction of astaxanthin was found to be sterospecific leading to th (4′R)‐hydroxy group irrespective of the configuration at C(3′), thus resulting in four different stereoisomers of idoxanthin formed from (3R,3′R), (3R,3′S; meso)‐, and (3S3′S)‐astaxanthin present in the diet.