bluuebunny/crossref_metadata_2025 huggingface dataset:
Spectra of Organic Molecules in Thin Films
Authors: Swalen J. D. , Tacke M. , Santo R. , Rieckhoff K. E. , Fischer J.
Published: December 2004

In order to investigate molecules and their interactions at interfaces we have developed a new spectroscopic technique based on integrated optics. A significant increase in sensitivity has been predicted and observed. We report here the details of the method and some preliminary spectra of organic dye molecules on thin films.
Partial Syntheses of Methyl Dehydrojasmonate and Tuberolactone
Authors: Dubs Paul , Stüssi Rita
Published: December 2004

The natural products methyl dehydrojasmonate (1) and tuberolactone (2) have been synthesized from methyl jasmonate (3) and jasmolactone (4) resp., via sulfenylation‐sulfoxide pyrolysis.
Über die Herstellung von Äther der enantio‐14, 15‐Dinorlabdan‐Reihe aus Eperusäure
Authors: Dey Ashesh Kumar , Wolf Hans Richard
Published: December 2004

The Conversion of Eperuic Acid into Ethers of the enantio‐14, 15‐Dinorlabdane Series

5 and 6 are strongly odiferous substances of the ambra‐type. Their enantiomers 7 and 8, hitherto unknown, have been synthesized from eperuic acid (4) and their olfactory properties compared with those of 5 and 6. 4 was esterified by CH2N2 and dehydrogenated with (C6H5Se)2/H2O2 to the α,β‐unsaturated ester 9 (61%). Oxidation by KMnO4 in acetone yielded the ketone 3 (60%). Epoxidation followed by treatment with acid converted 3 into the acetals 7 (61%) and 8 (14%). 7 and 8 differ from 5 and 6 in odor intensity, and 6 and 8 show slightly different odor quality.
Selective Removal of the o‐Nitrophenylsulfenyl Protecting Group in Peptide Synthesis
Authors: Tun‐Kyi Aung
Published: December 2004

2‐Thiopyridone (2‐mercaptopyridine, 1) was found to be a very suitable reagent for removing the Nα‐o‐nitrophenylsulfenyl (NPS‐) group in both conventional and solid‐support peptide synthesis. A 3‐ to 5‐molar excess of the reagent together with an equivalent amount of glacial acetic acid in methanol, dimethylformamide, or methylene chloride produces the soluble, stable mixed disulfide, 2‐nitrophenyl 2‐pyridyl disulfide (2), and the Nα‐deprotected amino‐acid or peptide. The yields are quantitative in less than 5 min if all educts are dissolved, in about 20 to 30 min in solid‐support synthesis. No modifications of either the indole side‐chain of tryptophan or of a series of side‐chain protecting groups, in particular of the t‐butyl type, are produced. No adverse side‐reactions (insoluble disulfides) were observed. The procedure is illustrated with a series of amino‐acid derivatives and with the solid‐support synthesis of [5‐leucine]‐enkephalin.
Rhodium (I)‐katalysierte Reaktionen der [2+4]‐Cycloaddukte aus 3,4‐Dimethoxyfuran und Acetylendicarbonsäure‐estern
Authors: Iten Peter Xaver , Eugster Conrad Hans
Published: December 2004

[2+4]‐Cycloaddition Products of 3,4‐Dimethoxyfuran with Acetylenedicarboxylates and Their Transformations under the Influence of Rhodium(I) Catalysts

3,4‐Dimethoxyfuran (1) readily reacts with acetylenedicarboxylates (2) at room temperature in a [2+4]‐cycloaddition to give a mono‐(3) and several di‐addition products. 90% of the latter consists of the endo‐exo compound 4. Under the influence of catalytic amounts of [Rh(CO)2Cl]2 the mixture of mono‐ and di‐adducts in methanolic solution is smoothly transformed into endo‐5,5,6‐trimethoxy‐7‐oxabicyclo [2.2.1]hept‐2‐ene‐2,3‐dicarboxylate

Alle Verbindungen sind racemisch. Die Formeln stellen jeweils nur ein Enantiomeres dar.

(5)
, 3‐hydroxy‐4,5‐dimethoxyphthalate (
6
) and (I
R
*, 2
S
*, 4
R
*, 5
R
*, 7
R
*, 11
R
*, 12
R
*) ‐5,8,8,9,12‐pentamethoxy‐3,6‐dioxatetracyclo [5.3.1.1
2,5
. 0
4,11
]dodec‐9‐ene‐1,11‐dicarboxylate

(
7
).
Activity, Selectivity, Decay and Long‐Term Behaviour of Amination Catalysts
Authors: Baiker Alfons , Richarz Werner
Published: December 2004

A survey of the activity and selectivity of several catalysts for the amination of long‐chain aliphatic alcohols with dimethylamine is given. The best results were obtained with Cu‐catalysts whose long‐term behaviour was investigated. The main reasons for catalyst decay are the irreversible adsorption of dimerization products and the thermal diffusive fusion of Cu‐crystallites.
A Theoretical Study of Complex Formation between Formaldehyde and Lithium
Authors: Ha Tae‐Kyu , Wild Urs P. , Kühne René O. , Loesch Charles , Schaffhauser Thierry , Stachel Johanna , Wokaun Alexander
Published: December 2004

Ab initio SCF and CI calculations on the cationic and neutral complexes of formaldehyde and lithium are reported. For the cationic complex CH2O/Li+, the stabilization energy of 41.7 kcal/mol obtained from the SCF calculation increases to 51.6 kcal/mol if a configuration interaction is introduced. For the neutral complex CH2O−/Li+, the C2v‐conformer of the 2A1‐state with the equilibrium bond distances of d(CO) = 1.23 Å and d (OLi) = 1.90 Å is calculated to be more stable than the 2B1‐state with d (CO) = 1.34 Å, and d (OLi) = 1.65 Å. Charge transfer and polarization effects upon complex formation are discussed.
Ruspolia hypercrateriformisM.R.: Isolierung und Strukturaufklärung von neuen Pyrrolidin‐Alkaloiden. 169. Mitt. über organische Naturstoffe
Authors: Roessler Felix , Ganzinger Dietmar , Johne Siegfried , Schöpp Emanuel , Hesse Manfred
Published: December 2004

Ruspolia hypercrateriformis M.R.: Isolation and Structure Elucidation of New Pyrrolidine Alkaloids

Three new pyrrolidine alkaloids have been isolated from Ruspolia hypercrateriformis, which belongs to the plant family of Acanthaceae. The structure of the alkaloids ruspolinone (1), norruspolinone (2) and norruspoline (3) (Scheme 1) has been elucidated by means of spectroscopic data of the pure compounds and their derivatives, by chemical transformation fo 2 to 1 by methylation, by trans‐formation of 3 and 2 to identical hydrogenation products, and by comparison of degradation products with synthetically prepared model compounds.
Préparation de quelques 4‐nitroisoxazoles à partir de pseudonitrosites de cétones éthyléniques du type chalcone
Authors: Hauff Jean‐Pierre , Tuaillon Jacques , Perrot Roger
Published: December 2004

The Synthesis of some 4‐Nitroisoxazoles from Pseudonitrosites of Chalcones

The action of dinitrogen trioxide with α,β‐unsaturated ketones of the chalcone type leads to pseudonitrosites (Table 1) which are cyclized to 4‐nitro‐3,5‐diarylisoxazoles (Table 2).
Synthese von zwei natürlich vorkommenden Lactonen mit 10gliedrigen Ringen: (±)‐Phoracantholid J und I
Authors: Gerlach Hans , Künzler Peter , Oertle Konrad
Published: December 2004

Synthesis of Two Naturally Occurring 10‐Membered Ring Lactones: (±)‐Phoracantholide J and I

Two 10‐membered ring lactones 7 and 11 from the metasternal secretion of the eucalypt longicorn Phoracantha synonyma have been synthesized by the following method. Reaction of the dilithium derivative of 4‐pentynoic acid (3) with 4‐tetrahydropyranyloxy‐1‐pentylbromide (2), followed by removal of the protecting group and by esterification with diazomethane, gave methyl 9‐hydroxy‐4‐decynoate (4; s. Scheme 1). Partial hydrogenation of the triple bond in 4 with Lindlar palladium catalyst, followed by saponification lead to cis‐9‐hydroxy‐4‐decenoic acid (6). The 9‐hydroxydecanoic acid (9) was synthesized by addition of methyl magnesium iodide to methyl 8‐formyloctanoate (8) followed by saponification (s. Scheme 2). The hydroxy acids 6 and 9 were converted into the S‐(2‐pyridyl) thioesters and cyclized in dilute benzene solution under the influence of silver ions to yield (±)‐phoracantholide J (7) and I (11) in 74 and 71% yield, respectively.
5, 7‐Dihydroxy‐8‐methoxy‐chroman‐4‐on aus dem Zwiebelwachs von Eucomis comosa
Authors: Heller Werner , Tamm Christoph
Published: December 2004

5, 7‐Dihydroxy‐8‐methoxy‐chroman‐4‐one from the Bulb Wax of Eucomis comosa

From the bulb wax of Eucomis comosa (HOUTT.) WEHRH. (Liliaceae) 5, 7‐dihydroxy‐8‐methoxy‐chroman‐4‐one (1) was isolated. The structure was confirmed by direct comparison with a synthetic specimen. 1 is the first natural chroman‐4‐one which is unsubstituted in the heterocyclic ring.
The Dianions of Phenanthrene and 1,2,3,4‐Dibenzocyclooctatetraene
Authors: Müllen Klaus
Published: December 2004

The dianions of phenanthrene and 1,2,3,4‐dibenzocyclooctatetraene have been prepared by metal reduction of the neutral compounds and characterized via the study of their 1H‐ and 13C‐NMR. spectra. A description of the charge distribution can be achieved which is consistent with both MO‐models and the spin density distribution of the corresponding radical anions. Thus, the dianion of 1,2,3,4‐dibenzocyclooctatetraene appears as a π‐bond delocalized species having its excess charge mainly localized in the eight membered ring.
A Chemical Study of Virginia Tobacco Flavour (Nicotiana tabacum L.) II. Isolation and synthesis of cis‐2‐isopropenyl‐8‐methyl‐1,2,3,4‐tetrahydro‐1‐naphthalenol and 3‐isopropenyl‐5‐methyl‐1,2‐dihydronaphthalene
Authors: Demole Edouard , Enggist Paul
Published: December 2004

Gas liquid chromatography allowed isolation of the novel cis‐2‐isopropenyl‐8‐methyl‐1,2,3,4‐tetrahydro‐1‐naphthalenol (A) and its dehydration product, 3‐isopropenyl‐5‐methyl‐1,2‐dihydronaphthalene (B), from two small subfractions of Virginia tobacco condensate. Both these norsesquiterpenes were identified on spectral grounds and synthesized from 1‐methylnaphthalene in a way (9 steps) that also afforded the «non‐natural», trans‐alcohol A′. The possible biogenesis of A and B in tobacco is briefly outlined.
Metal Complexes with Macrocyclic Ligands. IX. Synthesis and properties of a new class of branched N4‐macrocycles with an additional ligating group in the side chain
Authors: Lotz Tobias J. , Kaden Thomas A.
Published: December 2004

In the presence of Ni2+ the template reaction between 2,6‐diacetylpyridine and 4‐(2‐dimethylaminoethyl)‐ or 4‐(2‐hydroxyethyl)‐1, 7‐diamino‐4‐azaheptane yields the complexes of either the open‐chain ligand (3 and 11) or of the macrocycle (4 and 12). Reduction of the imino group in 4 and 12 with PtO2/H2 gives 5 and 13, respectively. In the case of the dimethylamino derivative 5 a mixture of at least four isomers was obtained. These were partially separated by chromatography on Sephadex SP‐25 cation exchanger. Through demetalation of the Ni2+ complexes by cyanide the new macrocycles 7 and 14 were isolated, from which the corresponding Zn2+ and Cu2+ complexes were prepared.

The macrocyclic Ni2+‐complexes 4, 12, 5 and 13 can exist in two forms depending on the pH of the solution. At low pH protonation of the dimethylamino or hydroxy group in the side chain occurs. The metal ion is then bound to the four nitrogen atoms of the macrocycle in a square planar ligand field. At higher pH, however, the dimethylamino or hydroxy group (the last one also in its deprotonated form) can coordinate to one of the axial positions, whereby pseudooctahedral coordination geometry is induced. This reaction can be quantitatively described by a reversible acid‐base equilibrium, the pKH of which greatly depends on the nature of the functional group, the degree of unsaturation of the macrocycle and the metal ion.

The acid‐base reaction and the concomitant structural change are a direct consequence of the unique combination of the rigid and kinetically stable structure of the macrocycle and of the flexible and kinetically labile functional group of the side chain.
Einfluss der Lipophilie von 3, 6‐Dioxakorksäurediamiden auf ihr Verhalten als Ionophore
Authors: Bissig René , Oesch Urs , Pretsch Ernö , Morf Werner E. , Simon Wilhelm
Published: December 2004

Influence of the lipophilicity of 3,6‐dioxaoctanedioic diamides on their ion carrier properties

A series of lipophilic 3,6‐dioxaoctanedioic diamides (potential ionophores for Ca2+) have been prepared. With increasing lipophilicity the ionophoric behavior of these ligands vanishes. This loss is shown to be due to kinetic limitations in the exchange reactions between aqueous phase and membrane phase.
Réactions chimiques oscillantes. II. Comportement de la «période d'induction» dans les systémes BrO/Ce4+/Cyclohexanone et BrO/Ce4+/Cyclopentanone
Authors: Farage Vincent J. , Janjic DéSimir
Published: December 2004

Oscillating Chemical Reactions. 11. Behaviour of the “induction period” in the BrO/Ce4+/Cyclohexanon and BrO/Ce4+/Cyclopentanon systems

The addition of α‐monobromoketone, one of the products of reaction of the BrO3−/Ce4+/Cyclohexanon (S1) and BrO3−/Ce4+/Cyclopentanon (S2) oscillating systems, decreases and even suppresses the induction period (τind.) in the case of S2.

Such is not the case with S1: τind. increases and the oscillations can even be completely inhibited.

The order of addition of the reagents and the time lapse (tadj.) preceding the addition of the last of them influences τind., particularly when the last reagent added is Ce4+.

In our experimental conditions, the inhibition of the oscillatory phenomenon by Cl− ions is definite only for | Cl− | ≥ 5,0 · 10−2M (S1) and |Cl−| > 2,5 · 10−3M (S2); for lower concentrations τind. increases with | Cl−|.
Elektrochemische Bildung von Δ1,2‐Norbornen
Authors: Stamm Erich , Walder Lorenz , Keese Reinhart
Published: December 2004

Electrochemical Formation of Δ1,2‐Norbornene

The electrochemical reduction of 1,2‐dihalogen norbornanes in tetrahydrofuran/furan leads to a mixture of two isomeric cycloadducts 6 and 7. The ratio of these adducts corresponds to those which have been found in reductive bisdehalogenation of 1 and 2 by butyllithium.
“Push‐Pull”‐Acetylene für die Peptid‐Synthese
Authors: Lienhard Ulrich , Fahrni Hans‐Peter , Neuenschwander Markus
Published: December 2004

“Push‐Pull” Acetylenes as Reagents for Peptide Synthesis

A series of ‘push‐pull’ acetylenes 1 is easily available from the corresponding “push‐pull” olefins by a simple bromination‐dehydrobromination sequence. The versatility of the acetylenes with regard to peptide synthesis is discussed.
Die massenspektrometrische retro‐Diels‐Alder‐Reaktion: 1, 2, 3, 4‐Tetrahydroisochinolin und 1, 2, 3, 4‐Tetrahydronaphthalin (Tetralin). 31. Mitteilung über massenspektrometrische Untersuchungen
Authors: Gretler Rudolf , Askitol̈ Elefteria , Kühne Hardy , Hesse Manfred
Published: December 2004

The Mass Spectral retro‐Diels‐Alder‐Reaction: 1,2,3,4‐Tetrahydroisoquinoline and 1,2,3,4‐Tetrahydronaphthaline (Tetraline)

The retro‐Diels‐Alder reaction of 1,2,3,4‐tetrahydroisoquinoline and of its N‐acetyl derivative was confirmed on the basis of labelled derivatives (Scheme 2). Furthermore, the loss of ethylene was investigated with the 1,2,3,4‐tetrahydronaphthalene‐ and 1,2,3,4‐tetrahydronaphthalen‐1‐one‐derivatives given in Schemes 4, 5 and 6. In the case of the 1,2,3,4‐tetrahydronaphthalen‐1‐one‐derivatives ethylene is lost via a retro‐Diels‐Alder reaction. The loss of ethylene from 1,2,3,4‐tetrahydronaphthalene (1) and from its derivatives is a rather complex reaction (Scheme 8): 1/3 of ethylene is split off 1+ via a formal retro‐Diels‐Alder reaction, 2/3 are lost after a specific rearrangement. The ratio of these two fragmentation pathways depends very much on the substituents placed at the aliphatic and the aromatic rings, compare e.g. Table 4.
[1,2,3]Triazoloazine/(Diazomethyl)azine Valence Tautomers from 5‐Azinyltetrazoles
Authors: Wentrup Curt
Published: December 2004

[1,2,3]Triazoloazines are formed by thermolysis of 5‐azinyltetrazoles in the gasphase or in solution. Thus, 5‐(2‐pyridyl)tetrazole (7) and 5‐(2‐pyrazinyl)tetrazole (11) yield [1,2,3]triazolo[1,5‐a]pyridine (9) and [1,2,3]triazolo[1,5‐a]pyrazine (13), respectively, at 400°/10−3 ‐ 10−5 Torr. 5‐(2‐Phenyl‐4‐quinazolinyl)tetrazole (15) gives 5‐phenyl[1,2,3]triazolo[1,5‐c]quinazoline (17) in 75% yield by heating under reflux in mesitylene solution. 2‐(Diazomethyl)pyridine (8), a valence tautomer of 9, can be trapped by fumaronitrile, leading to 3‐(2‐pyridyl)‐1, 2‐cyclopropanedicarbonitrile (19). The [1,2,3]triazoloazines undergo base catalysed H/D‐exchange in D2O solution.
Zur Aktivierung partiell silylierter Kohlenhydrate mittels Triphenylphosphan/Azodicarbonsäureester
Authors: Brandstetter Hannelore H. , Zbiral Erich
Published: December 2004

On the Activation of Partially Silylated Carbohydrates Using Triphenylphosphane/Diethylazodicarboxylate

Reaction of methyl α‐D‐glucopyranoside (1) with two equivalents of t‐butyldimethylchlorosilane yields methyl 2,6‐bis[O‐(t‐butyldimethylsilyl)]‐α‐D‐glucopyranoside (1a) and methyl 3,6‐bis[O(t‐butyldimethylsilyl)]‐α‐D‐glucopyranoside (1b) in a ratio of 4:1. The anomeric β‐pyranoside 2 affords methyl 2,6‐bis[O(t‐butyldimethylsilyl)]‐β‐D‐glucopyranoside (2a) and methyl 3,6‐bis[O(t‐butyldimethylsilyl)]‐β‐D‐glucopyranoside (2b) in nearly equal amounts. 2b is isomerized to methyl 4,6‐bis[O(t‐butyldimethylsilyl)]‐β;‐D‐glucopyranoside (2c) (83%) and 2a (10%) with triphenylphosphane/diethylazodicarboxylate. Structures were assigned by NMR.‐analysis and CD.‐analysis of the corresponding benzoates 1c, 1d and 2d and of the acetates 2e and 2f.

1a is transformed into methyl 4‐azido‐2, 6‐bis[O(t‐butyldimethylsilyl)]‐4‐deoxy‐α‐D‐galactopyranoside (3) with triphenylphosphane/diethylazodicarboxylate/HN3. 2a and 2c yield the 3‐azido‐allosides 5 and 7 respectively under similar conditions. The activation by triphenylphosphane/diethylazodicarboxylate is high enough to introduce also p‐nitrobenzoate groups with inversion of configuration at the reaction center. By this way 1a and 2a give methyl 2, 6‐bis[O(t‐butyldimethylsilyl)]‐4‐O‐p‐nitrobenzoyl‐α‐D‐galactopyranoside (4) and methyl 2, 6‐bis[O‐(t‐butyldimethylsilyl)]‐3‐O−ptrobenzoyl‐β‐D‐allopyranoside (6) respectively. For elucidation of structures the acetate derivatives 3a‐7a were prepared.
Chemically modified silicon dioxide surfaces. Wetting properties of compact n‐alkyl‐dimethylsiloxy layers, and their mixed surface crystals. The Question of Wetting of Molecularly Rough and of Swollen Surfaces
Authors: Riedo François , Czencz Maria , Liardon Olivier , Kováts Ervin sz.
Published: December 2004

By means of contact angle measurements, it has been shown that compact alkyl‐dimethyl‐siloxy layers can be obtained on the surface of acid leached glass using the method previously developed for fume silica. Subsequently, a series of densest possible alkyl‐dimethylsiloxy layers were prepared having non‐branched alkyl substituents, CzH2z+1, (with z=1, 2, 3, 6, 10, 14, 18 and 22) and wetting angles were measured as a function of the temperature. On surfaces coated with longer alkyl substituents the formation of mixed crystals, consisting of the sparse chemically bonded alkyl layer and a n‐alkane acting as a wetting agent, has been observed at low temperatures. At higher temperatures such surfaces appeared to be «molten», and at the same time swollen by the wetting agent. Equations have been derived to deduce the free surface energies and to account for the wetting properties of rough and swollen surfaces. Application of the results to the data presented in this paper revealed that glass surfaces covered with short alkyl chains (methyl, ethyl and propyl) are rough and those covered with long chains (tetradecyl, octadecyl and docosyl) are swollen. Surfaces formed by hexyl‐ and decyl‐dimethylsiloxy substituents exhibit intermediate properties.
Esters phosphoriques, phosphonates et oxydes de phosphine dérivés de sucres. Communication préliminaire
Authors: Tronchet Jean M. J. , Neeser Jean‐Richard , Charollais Etienne J.
Published: December 2004

Some sugar phosphates, phosphonates and phosphine oxides, Preliminary communication

Some new phosphates of 1, 2‐O‐isopropylidene‐α‐D‐ribofuranose have been prepared. Reactions of 3‐C‐cyanomethylidene‐3‐deoxy‐1, 2‐O‐isopropylidene‐5‐O‐trityl‐α‐D‐erythro‐pentofuranose (9) have been studied. On treatment with phosphorus nucleophiles, 9 led to phosphorus bearing branched‐chain sugar derivatives. Branched‐chain cyanosugars as 15 and 16 prepared by cis‐vic‐dihydroxylation of 9 constitute interesting potential precursors of new types of cyclic sugar phosphates.
Edulon A, ein 2H‐1‐Oxapyrenderivat aus Plectranthus edulis (Labiatae)
Authors: Buchbauer Gerhard , Rüedi Peter , Eugster Conrad Hans
Published: December 2004

Edulon A, a Derivative of 2H‐1‐Oxapyrene from Plectranthus edulis (Labiatae

From the coloured leaf‐glands of the above mentioned East‐african labiate we have isolated Edulon A, A new, deeply coloured diterpenoid. Based mainly on spectroscopic arguments, we propose its structure to be (5a R, 1′ ζ)‐10‐(2′‐acetoxy‐1′‐methylethyl)‐6, 7, 9‐trihydroxy‐3, 5a‐dimethyl‐4, 5, 5a, 8‐tetrahydro‐2H,‐l‐oxapyrene‐2, 8‐dione (1a). The compound may be regarded as a 4, 5‐seco‐abietane derivative that has formed new bonds (between C(18 or 19)COOH and C(12)OH), and between C(3) and C (11)) by lactonisation and condensation, respectively.
Biosynthesis of Mikrolin
Authors: Chexal Kuldip K. , Tamm Christoph
Published: December 2004

Mikrolin (8) and dechloromikrolin (9) have been shown to exist as tautomeric mixtures in solution. The structures of mono‐O‐trifluoroacetyl Mikrolin (10) and di‐O‐acetyl Mikrolin (11) have been elucidated. The products 15 to 23 from reduction of the metabolites 8 9 with Pd/C and Zn in aqueous acetic acid have been identified. The 13C‐NMR. spectra of Mikrolin (8) and dechloromikrolin (9) and their derivatives have been completely assigned Based on the results of incorporation experiments with sodium [1‐13C]‐, [2‐13C]‐ and [1, 2‐13C]‐acetate, a biosynthetic pathway is proposed for Mikrolin (8).
Chloracylierung und Bromacylierung von Carbonylverbindungen: Eine in Vergessenheit geratene Carbonylreaktion. I. Präparative Anwendungsbreite
Authors: Neuenschwander Markus , Bigler Peter , Christen Klaus , Iseli Rudolf , Kyburz Rolf , Mühle Hansueli
Published: December 2004

Chloroacylation and bromoacylation of carbonyl compounds: A forgotten carbonyl reaction. I. Scope of the reaction

Aliphatic, α,β‐unsaturated and aromatic aldehydes as well as aliphatic ketones react with acyl halides to (α‐haloalkyl)esters. These bifunctional derivates contain two leaving groups of different reactivity. The scope of this scarcely of this scarcely known carbonyl reaction is discussed.
Chloracylierung und Bromacylierung von Carbonylverbindungen. II. Analyse der Nebenprodukte
Authors: Bigler Peter , Schönholzer Stefan , Neuenschwander Markus
Published: December 2004

Chloroacylation and bromoacylation of carbonyl compounds II. Structure of the by‐products

The structures of the by‐products formed in the reaction between paraformaldehyde and acetyl chloride as well as between acetaldehyde and acetyl chloride are elucidated. Optimum conditions for a high yield of the (α‐chloroalkyl) ester 1 were obtained by variation of structure and reaction parameters. A speculative reaction scheme of the formation of by‐products is discussed.
Gleichgewichtsgeometrie und spektroskopische Eigenschaften des Biphenyls im S0‐und S1‐Zustand
Authors: Gustav Klaus , Sühnel Jürgen , Wild Urs P.
Published: December 2004

Equilibrium geometry and spectroscopic properties of biphenyl in the S0 and S1 state

Equilibrium geometries for the S0 and S1 state of biphenyl were determined by minimization of the total energy with respect to all cartesian coordinates. The molecule is twisted in the S0 state (20°), but becomes planar in the S1 state. Using these results, an interpretation of the fluorescence and absorption spectra can be given. In passing from the S0 to the S1 state equilibrium geometry a remarkable change of the state ordering occurs.
Chloracylierung und Bromacylierung von Carbonylverbindungen. III. Lage des Gleichgewichts
Authors: Bigler Peter , Neuenschwander Markus
Published: December 2004

Chloroacylation and Bromoacylation of Carbonyl Compounds III. Reactant/Product Equilibria

Aliphatic, α, β‐unsaturated and aromatic aldehydes 1 as well as aliphatic ketones react with acyl halides 2 to α‐haloalkyl esters 3. In the presence of Lewis acids there is an equilibrium between reactants and product. The position of the equilibrium depends on the nature of the carbonyl compound as well as that of the acyl halide: The products 3 are favoured in the case of aldehydes, cyclobutanone and cyclohexanone, and the equilibrium constant increases in the series F < Cl < Br < I. Low reaction temperature, nonpolar solvents as well as high reactant concentrations favour the product 3.
Cyclodextrin chemistry. Selective modification of all primary hydroxyl groups of α‐ and β‐cyclodextrins
Authors: Boger Joshua , Corcoran Richard J. , Lehn Jean‐Marie
Published: December 2004

Two efficient methods are described for the selective modification of all six primary hydroxyl groups of α‐cyclodextrin (α‐CD, 11). One, using an indirect strategy, involves protection of all 18 hydroxyl functions as benzoate esters, followed by selective deprotection of the six primary alcohol groups. The other, using a direct strategy, involves selective activation of the primary hydroxyl groups via a bulky triphenylphosphonium salt, which is then substituted by azide anion as the reaction proceeds. A number of modified α‐cyclodextrin derivatives have been prepared and fully characterized, among which are: the useful intermediate α‐cyclodextrin‐dodeca (2, 3) benzoate (3); hexakis (6‐amino‐6‐deoxy)‐α‐cyclodextrin hexahydrochloride (7); hexakis (6‐amino‐6‐deoxy)‐dodeca (2, 3)‐O‐methyl‐α‐cyclodextrin hexahydrochloride (9), hexa (6)‐O‐methyl‐α‐cyclodextrin (13). The direct substitution is shown to be even more efficient for β‐cyclodextrin (16), giving the heptakis (6‐azido‐6‐deoxy)‐β‐CD‐tetradeca (2, 3)acetate (17), while the indirect strategy fails. The compounds are characterized by extensive use of 13C‐ and 1H‐NMR. spectroscopy. The steric and statistical problems of selective polysubstitution reactions for the cyclodextrins are discussed, and possible reasons for the observed differences in reactivity between α‐ and β‐cyclodextrins are examined.

The dodecabenzoate 3 presents a very marked solvent effect on physical properties (IR. and NMR. spectra, optical rotation); the effects observed may be ascribed to an unusually strong intramolecular network of hydrogen bonds which severely distorts the α‐cyclodextrin ring and lowers the symmetry from six‐fold to three‐fold.
Über Pterinchemie 67. Mitteilung Zum Verlauf der katalytischen Reduktion von 6, 7‐Diphenylpterin
Authors: Antoulas Symeon , Bieri Jost H. , Viscontini Max
Published: December 2004

On the pathway of the catalytic reduction of 6,7‐diphenylpterin

The pathway of the hydrogen addition to the pyrazine ring of 6, 7‐diphenylpterin (1a) during acid‐catalyzed reduction was elucidated. Initial hydrogenation of the 5, 6‐double bond produces 6, 7‐diphenyl‐5, 6‐dihydropterin (2a); this then undergoes a [1, 2]‐H‐rearrangement, which yields the thermodynamically more stable 6, 7‐diphenyl‐7, 8‐dihydropterin (3a).

Subsequent reduction of 3a gives 4.
An Enantioselective Total Synthesis of Natural (+)‐Luciduline
Authors: Oppolzer Wolfgang , Petrzilka Martin
Published: December 2004

The naturally occurring Lycopodium alkaloid (+)‐luciduline (1) has been synthesized from (R)‐5‐methyl‐cyclohex‐2‐en‐1‐one (12) by a sequence of seven steps (s. Scheme 6) in 33% overall yield. The key step 4→6 presumably involves a transient nitrone 5 which undergoes a highly regioselective intramolecular addition to a non‐polarized olefinic bond.
Preference for Syn Ene Additions of 1O2 to Trisubstituted, Acyclic Olefins
Authors: Schulte‐Elte Karl H. , Muller Bernard L. , Rautenstrauch Valentin
Published: December 2004

Dye‐sensitized photooxygenations of 3 pairs of (E)/(Z) trisubstituted olefins were studied in order to establish the partitioning between the 3 possible ene additions. The (E)‐isomers underwent only the 2 ene additions (>95%) involving H‐atom abstractions at the same, disubstituted side of the olefins, termed syn ene additions, with almost equal ease. The (Z)‐isomers underwent mainly (85‐90%) the syn ene additions, with the ones leading to the tertiary hydroperoxides distinctly favoured, and some (10‐15%)ene additions at the monosubstituted side of the olefin, termed anti ene addition.
Über 3,3,6,9,9‐Pentamethyl‐2,10‐diaza‐bicyclo‐[4.4.0]‐1‐decen und einige seiner Derivate. Über synthetische Methoden. 13. Mitteilung
Authors: Heinzer Franz , Soukup Milan , Eschenmoser Albert
Published: December 2004

3,3,6,9,9‐Pentamethyl‐2,10‐diaza‐bicyclo[4.4.0]‐1‐decen and some of its derivatives

A simple synthesis for the bicyclic amidine 1 (Scheme 3) is described. This base and the salts which were prepared from it show solubility characteristics which make the amidine a potentially useful reagent for salt formation of carboxylic acids and related proton complexes of bidentate ligands. Among the derivatives made from 1 are the sterically strongly hindered N‐alkylated amidines 11, 12 and 14 (Scheme 5), as well as the stable crystalline N1‐oxidoamidine‐N2‐oxyl radical 2 (Scheme 6). The ability of the latter to serve as a paramagnetic chelating ligand for metal ions is illustrated by the preparation of a corresponding nickel(II) complex. The radical is also a source for the α‐nitronyl‐nitrosonium cation 4 which shows in its reactivity towards conjugated dienes and olefines some of the expected resemblance to singlet oxygen.
Anil‐Synthese 18. Mitteilung. Über die Herstellung von Styryl‐Derivaten des 3‐Phenyl‐benzisoxazols
Authors: De Sousa Benardo F. S. E. , Siegrist Adolf Emil
Published: December 2004

Preparation of styryl derivatives of 3‐phenyl‐benzisoxazole

3‐(p‐Tolyl)‐1,2‐or 2, 1‐benzisoxazoles and 6‐methyl‐3‐phenyl‐1,2‐benzisoxazoles react with anils of aromatic aldehydes in the presence of dimethylformamide and potassium hydroxide or potassium t‐butoxide to yield the corresponding 3‐(stilben‐4‐yl)‐1,2‐ or 2,1‐benzisoxazoles and the 3‐phenyl‐6‐styryl‐1,2‐benzisoxazoles respectively (‘Anil Synthesis’). Further, the Schiff's bases derived form chloroanilines and 3‐(p‐formylphenyl)‐1,2‐benzisoxazoles yield, with methyl‐and p‐tolyl substituted heterocyles the corresponding heterocyclic substitued styryl and stilbenyl derivatives.
Zur Kenntnis der β‐Lysin‐Mutase‐Reaktion: Mechanismus und sterischer Verlauf
Authors: Rétey János , Kunz Fritz , Arigoni Duilio , Stadtman Thressa C.
Published: December 2004

Investigations on the β‐lysine mutase reaction: Mechanism and steric course

The steric course and some mechanistic aspects of the coenzyme‐B12‐dependent β‐lysine‐mutase reaction, in which (3 S)‐β‐lysine is converted to (3 S, 5 S)‐3, 5‐diaminohexanoate, have been investigated by means of tritium labelling. The reaction involves migration of an hydrogen atom from C(5) of the substrate to C(5′) of coenzyme B12 and back‐transfer to C(6) of the product. In the presence of [5′‐3H]‐coenzyme B12 the enzyme catalyzes the exchange of label between the cofactor and one of the diastereotopic H‐atoms at C(5) of the substrate. The exchangeable hydrogen atom is identical with the one specifically involved in the migration reaction. Degradation of the tritiated β‐lysine obtained in such experiments yielded a sample of tritiated succinic acid which was shown in an enzymic assay involving partial oxidation with succinate dehydrogenase, to possess the (S)‐configuration. Thus, the overall substitution at C(5) occurs with inversion of configuration.
Stereochemie der Bildung und Spaltung der (CoC)‐Bindung an einem Vitamin‐B12‐Modell 3. (vorläufige) Mitteilung
Authors: Walder Lorenz , Rytz Gerhard , Meier Kurt , Scheffold Rolf
Published: December 2004

Stereochemical Course of the Formation and Cleavage of the CoC Bond in a Vitamin B12 Modal

The electrosynthesis and properties of a chiral cobalt alkyl complex 4 are described. The reductive cleavage of the Co–C bond occurs with retention of configuration at the C‐atom.
1, 5, 6, 7‐Tetrahydro‐2H‐[1,4]diazepin‐5,7‐dione aus Malonimiden und 3‐Dimethylamino‐2,2‐dimethyl‐2H‐azirin
Authors: Scholl Bernhard , Bieri Jost H. , Heimgartner Heinz
Published: December 2004

1, 5, 6, 7‐Tetrahydro‐2H‐[1, 4]diazepin‐5, 7‐diones from Malonimides and 3‐Dimethylamino‐2, 2‐dimethyl‐2H‐azirine

Reaction of the aminoazirine 1 with malonimides of type 7 in 2‐propanol at room temperature leads to the 1,4‐diazepine derivatives of type 9 (Scheme 3). The structure of 6, 6‐diethyl‐3‐dimethylamino‐2,2‐dimethyl‐1,5,6, 7‐tetrahydro‐2H‐ [1,4] diazepin‐5, 7‐dione (9a) has been proved by single crystal X‐ray analysis (Chapter 4). Reduction of the 7‐membered heterocycle 9a with sodium borohydride yields the perhydro‐[1,4]diazepin‐5, 7‐dione 10, while 9a in ethanol at 60° undergoes a ring contraction to the 4 H‐imidazole derivative 11a (Scheme 4): Mechanisms of these two reactions are discussed in comparison with previously reported reactions (Chapter 5).
A New Method for the Construction of Macrolides Stereoselective Synthesis of (±)‐Phoracantholide J. Preliminary communication
Authors: Petrzilka Martin
Published: December 2004

Starting from 5‐chloro‐2‐pentanone (1) the naturally occurring 10‐membered lactone phoracantholide J (8a) has been synthesized as its racemate in a sequence of six steps (Scheme 2). Salient features of the syntheis include an internal selenium assisted acetal formation (4→5) and a stereoselective Claisen rearrangement (6→7→8). This general synthetic strategy offers an alternative approach towards the construction of macrocyclic lactones.
A New Type of Claisen Rearrangement Involving 1,3‐Dipolar Intermediates. Preliminary communication
Authors: Malherbe Roger , Belluš Daniel
Published: December 2004

During the reaction of allyl ethers, allyl sulfides and allyl selenides with in situ prepared dichloroketene (1), 2 competing pathways are observed. Besides [2+2]‐cycloaddition, an unprecedented [3,3]‐sigmatropic (Claisen) rearrangement via a 1,3‐dipolar intermediate takes place. It leads to O‐, S‐ or Se‐esters of α,α‐dichloro‐γ, δ‐unsaturated acids containing an inverted allylic group. Starting from cyclic n‐membered α‐vinyl‐substituted ethers, lactones with n+4‐membered rings are formed. A very facile synthesis of the naturally occurring macrolides (±)‐phoracantholide I (10) and (±)‐phoracantholide J (11) illustrates the synthetic utility of this new ‘ketene’ Claisen rearrangement.
Nucleosid‐Synthesen in der Imidazolreihe
Authors: Wyss Pierre C. , Fischer Ulf
Published: December 2004

Synthesis of Imidazole Nucleosides

The acid‐catalyzed fusion of dimethyl imidazole‐4,5‐dicarboxylate (7) with 1‐O‐acetyl‐2,3,5‐tri‐O‐benzoyl‐β‐D‐ribofuranose (6) provided dimethyl 1‐(2,3,5‐tri‐O‐benzoyl‐β‐D‐ribofuranosyl)imidazole‐4,5‐dicarboxylate (11) as the major product together with some β‐anomer (13). The β‐anomer (11) was obtained as the only product when the trimethylsilyl derivative (9) of 7 was condensed with 6 in the presence of stannic chloride. Nucleoside 11 was treated with ammonia, and various primary amines to provide 1‐β‐D‐ribofuranosylimidazole‐4, 5‐dicarbox‐amide (5) and N, N'‐disubstitued dicarboxamides (18‐26) respectively. The synthesis of 1‐β‐(33) and 1‐β‐D‐arabinofuranosylimidazole‐4,5‐dicarboxamide (34), is also described. The conformation of 5, as studied by 1H‐and 13C‐NMR.‐spectroscopy, was shown to be very similar to that of adenosine.

The oxidation of the 2′,3′‐O′‐isopropylidene derivative (15) of 5 with potassium permanganate or chromic oxide, followed by deprotection, or the direct oxidation of 5 with oxygen in the presence of platinum catalyst, led to the corresponding 5′‐carboxylic acid 36. This was further converted into esters (37 and 38) and amides (39‐42).

Treatment of some nucleosides with fuming nitric acid in oleum at ‐ 30° yielded the nitric acid esters 43‐51. Beside the nitration of their sugar residues, one of the imidazolecarboxamide functions in nucleosides 46‐51 and both N‐methyl‐carboxamide functions in 44 were nitrated. Finally, reaction of the N, N'‐dimethyl‐N, N'‐dinitrodicarboxamide 44 with alkyl‐ und aralkylamines, afforded the N, N'‐dialkyl‐and N, N'‐diaralkyldicarboxamides 52‐56.
(cis‐6‐Methyltetrahydropyran‐2‐yl)acetic Acid, a Novel Compound from Civet (Viverra civetta)
Authors: Maurer Bruno , Grieder Alfred , Thommen Walter
Published: December 2004

The isolation and synthesis of (cis‐6‐methyltetrahydropyran‐2‐yl)acetic acid (1a), a novel compound from civet (Viverra civetta), are reported.
Déconjugaison d'énones dérivées de sucres Communication préliminaire
Authors: Tronchet Jean M. J. , Gentile Bernard , Nguyen‐Xuan Tho
Published: December 2004

Deconjugation of sugars enones. Preliminary Communication

Branched‐chain sugar enones 1 and 2 (R = Ac) deconjugated toposelectively (only the E isomers reacting) to 3. The same phenomenon was noted in the case of Z‐4 which gave E‐5. The kinetic parameters of these reactions favored a concerted mechanism, i.e. a [1, 5]‐sigmatropic shift.
Specifically (π → π*)‐Induced Cyclohexenone Reactions 6‐Benzylbicyclo [4.4.0]dec‐1‐en‐3‐ones
Authors: Mariaca Raul , Schaffner Kurt
Published: December 2004

6‐Benzylbicyclo [4.4.0]dec‐1‐en‐3‐one (9) and the 2‐methyl homologue (10) underwent a (γ → α )‐1, 3‐benzyl shift to the β,γ‐unsaturated ketones 21 and 22, respectively, when excited in the π π* absorption band. The quantum yield was ca. 0.1 at 254 nm for the formation of both products in alkane solvents. These reactions occur specifically from the S2(π, π*) state in competition with its decay to the S1(n, π*) and T states. The triplet reaction of 9, initiated by n → π* irradiation and by sensitization, was a double‐bond shift to 20, whereas no identifiable product was observed from 10 under these conditions. Direct and acetone‐sensitized irradiations of 21 and 22 resulted in oxadi‐π‐methane rearrangements to mixtures of syn‐ and anti‐30 and syn‐ and anti‐31, respectively.
Aromastoffe der roten Passionsfrucht. Zwei neue Edulanderivate
Authors: Winter Max , Schulte‐Elte Karl H. , Velluz Alain , Limacher Josef , Pickenhagen Wilhelm , Ohloff Günther
Published: December 2004

Aroma Constituents of the Purple Passion Fruit. Two New Edulan Derivatives

The isolation of (2R*, 4S*, 4aS*, 8aS*)‐4,4a‐epoxy‐4,4a‐dihydroedulan (1), and (2R*, 3S*, 8aS*)‐3‐hydroxyedulan (2), two new constituents of the purple passion‐fruit (Passiflora edulis SIMS), is reported.

Racemic epoxide 1 was synthesized by oxidation of edulan 6 with peracidic acid, and racemate of alcohol 2 was obtained by reduction of ketone 7, one of the chromic acid oxidation‐products of edulan 6.
Réactions de germylènes avec divers oxirannes et le thiiranne. Mise en évidence de germanones et germathiones intermédiaires. Communication préliminaire
Authors: Barrau Jacques , Bouchaut Marsan , Lavayssiere Hélène , Dousse Gabriel , Satgé Jacques
Published: December 2004

Complexed dialkylgermylenes R2GeNR3 or R2GePy react with oxiranes or thiirane and lead to dialkylgermanone and germathione via germaoxetanes or germathiacyclobutane. The formation of germadioxolanes or germadithiolane finally observed arises from condensation of dialkylgermanone (or germathione) on oxiranes (or thiirane).
Notiz zur Synthese von rac. cis‐ und trans‐2‐Nor‐abscisinsäure
Authors: Kienzle Frank
Published: December 2004

Note on the synthesis of rac. cis‐ and trans‐nor‐abscisic acid

The synthesis of the 2‐nor‐analogues of cis‐ and trans‐abscicic acid is described.
Additionsreaktion von 3‐Dimethylamino‐2,2‐dimethyl‐2H‐azirin mit Phenylisothiocyanat
Authors: Schmid Ursula , Heimgartner Heinz , Schmid Hans
Published: December 2004

Reaction of 3‐Dimethylamino‐2,2‐dimethyl‐2H‐azirine with Phenyl Isothiocyanate

In contrast to the reactions of 3‐dimethylamino‐2,2‐dimethyl‐2H‐azirine (1a) with various isothiocyanates, leading to thiazoline derivatives, the reaction of 1a with phenyl isothiocyanate at room temperature gives 5,5‐dimethyl‐3‐phenyl‐Δ1‐imidazolin‐4‐dimethyliminium‐2‐thiolate (9, Scheme 2). The structure of 9 is deduced from spectral data and reactions of this zwitterionic compound (Schemes 2 and 4).
Photolyse des 3‐Phenyl‐2, 1‐benzisoxazols und einiger seiner Derivate in Bromwasserstoffsäure
Authors: Giovannini Edgardo , De Sousa Bernardo F. S. E.
Published: December 2004

Photolysis of 3‐phenyl‐2, 1‐benzisoxazole and some derivatives in hydrobromic acid

The behaviour of 3‐phenylanthranils (3‐phenyl‐2, 1‐benzisoxazoles) towards photolysis in hydrobromic acid differs greatly from that in hydrochloric and sulfuric acid. Thus, reduction and substitution products are obtained. The formation of the reduction products involves hydrogen abstraction by a nitrenium ion species in the triplet state and that of the substitution products can be attributed to a subsequent SE‐bromination.
Secondary 2‐Norbornyl Cation Intermediates Substituted at C(5) and C(7) by Electron‐withdrawing Groups. Addition of fluorosulfuric acid to unsaturated norbornane derivatives
Authors: Quarroz Daniel , Vogel Pierre
Published: December 2004

Low temperature (−130° to −110°) addition of exo‐norborn‐5‐en‐2‐ol (7) to excess HSO3F in SO2CIF yielded a mixture of exo‐5‐(fluorosulfonyloxy)‐exo‐2‐ and endo‐2‐norbornylhydroxonium ions (9+10) under kinetic control that was different from the mixture of 9+10 obtained by addition of endo‐norborn‐5‐en‐2‐ol (8) to HSO3F under kinetic control. These mixtures differed from the mixture of 9+10 observed at higher temperature (−80° to −60°) (thermodynamic control). Addition of 3‐nortricyclanol (23) or exo‐2, 3‐epoxynorbornane (24) to HSO3F at ‐−120° ± 10° yielded a mixture containing the exo‐2‐(fluorosulfonyloxy)‐anti‐7‐ and syn‐7‐norbornylhydroxonium ions (26+27) as major adducts. Qualitative rates of the isomerization of 26+27 to the more stable ions 9+10 and of the isomerization 9 ⇄ 10 were evaluated. The solvolysis of 9+10 in HSO3F yielded the exo‐2, exo‐5‐ and exo‐2, endo‐5‐norbornanediyl bis (fluorosulfates) (21+22). Norbornadiene and quadricyclane added 2 equivalents of HSO3F and furnished kinetically a mixture of exo‐2, anti‐7‐ and exo‐2, syn‐7‐norbornanediyl bis (fluorosulfates) (36+37) as major adducts. The latter 36+37 were isomerized into a kinetic mixture of the more stable isomers 21+22. The rates of these isomerizations were compared. The use of DSO3F and (exo‐2‐D)‐norborn‐5‐en‐2‐ol (15) confirmed that heterolyses of the fluorosulfates were responsible for the observed isomerization; elimination‐addition processes occurred but much more slowly. The results are interpreted in terms of substituted classical and σ‐bridged secondary 2‐norbornyl cation intermediates. It appears that the electron withdrawing substituents FSO3 and H2O+ (HO) destabilize the σ‐bridged 2‐norbornyl cation more at C(5) than C(7). If the σ‐bridged ions 5‐Z substituted at C(5) by Z = FSO3 or H2O+ (HO) are transition states in the isomerization of the corresponding classical ions 3‐Z, 4‐Z, the free enthalpy difference between the ‘non‐classical’ σ‐bridged ion and the classical ions is not higher than the energy barrier to the quenching of the latter intermediates by FSO in HSO3F/SO2CIF.
Syntheses and Absolute Configuration of (E)‐ and (Z)‐α‐Bisabolenes
Authors: Delay Franç , Ohloff Günther
Published: December 2004

Stereospecific syntheses of (E)‐ and (Z)‐α‐bisabolenes have made revision of the configuration of natural (+)‐α‐bisabolene from Opoponax oil necessary. 13C‐NMR. spectroscopy has been used for the differentiation of these isomers.
Synthesis, Opiate Receptor Binding and Analgesic Activity of Enkephalin Analogues
Authors: Pless Janos , Bauer Wilfried , Cardinaux Francis , Closse Annemarie , Hauser Daniel , Huguenin René , Roemer Dietmar , Buescher Heinz‐Hermann , Hill Ronald Charles
Published: December 2004

The synthesis and biological testing of analogues of Met‐enkephalin, a recently discovered opioid peptide from mammalian brain, are described. Testing involved determination of affinity constants for an opiate receptor site and of analgesic potency in the tail‐flick test in mouse. The effects on opioid activity of modifying various parts of the enkephalin molecule are discussed. Tyr‐D‐Ala‐Gly‐MePheMet (O)‐ol

The ending ‐ol added to the symbol of an amino acid designates the aminoalcohol obtained by reduction of the α‐carboxyl group of the amino acid.

(FK 33‐824), which was highly active in these tests, was subsequently selected for clinical testing.

The use of two complementary models ‐ in vitro binding studies and in vivo test for analgesia ‐ for the assessment of biological activity in the evaluation of analogues is explained.
The Synthesis and Reactions of Dialkyl 1‐Vinylvinyl‐Phosphates
Authors: Kienzle Frank , Rosen Perry
Published: December 2004

3,4‐Dichlorobutanone reacts with trialkyl phosphites to give dialkyl 1,3‐butadien‐2‐yl phosphates. Their structures were determined by spectroscopic methods and various chemical reactions.
Totalsynthese von natürlichem α‐Tocopherol. 2. Mitteilung. Aufbau der Seitenkette aus (−)‐(S)‐3‐Methyl‐γ‐butyrolacton
Authors: Schmid Max , Barner Richard
Published: December 2004

Total Synthesis of Natural α‐Tocopherol

A short and efficient route to optically pure (+)‐(3 R, 7 R)‐trimethyldodecanol (14) is demonstrated, 14 serving as side chain unit in the preparation of natural vitamin E. The synthesis of 14 is based on the concept of using a single optically active C5‐synthon of suitable configuration and functionalization to introduce both asymmetric centres in 14. (−)‐(S)‐3‐Methyl‐γ‐butyrolacton (1) and ethyl (−)‐(S)‐4‐bromo‐3‐methylbutyrate (2), respectively, is used in a sequence of either two Grignard C,C‐coupling reactions 5 → 8 and 12 → 13 or two Wittig reactions 17a → 18 and 20 → 21 to achieve this goal. 14 is converted to (2 R, 4′R, 8′R)‐α‐tocopherol (= vitamin E) by coupling with a chroman unit in known manner. Optical purity of products and intermediates is established.
ipso‐Substitution with Sodium‐N‐alkyl‐(p‐nitrobenzene)sulfonamide. A novel anionic rearrangement
Authors: Müller Paul , Phuong Nguyen‐Thi Minh
Published: December 2004

Reaction of N‐benzyl‐N, N‐di‐(p‐nitrobenzene)sulfonamide (3) with NaCN/HMPA at 140° affords N‐benzyl‐p‐nitroaniline (4). The same product is obtained upon heating of the sodium salt of N‐benzyl‐(p‐nitrobenzene)sulfonamide (5). The transformation 5 → 4 is believed to proceed via an anionic episulfonyl compound 6.
Selective Hydrogen Chloride Elimination from Primary Chlorides Induced by the Fluoride Anion. Anchimeric participation of the chloromethyl group in the heterolytic opening of an epoxide. Stereospecific syntheses of 5,6‐bis (methylidene)‐syn‐2‐norbornen‐7‐ol and 5,6‐bis (methylidene)‐endo‐3‐chloro‐exo‐2‐norbornanol
Authors: Chollet André , Hagenbuch Jean‐Pierre , Vogel Pierre
Published: December 2004

Syntheses of the alcohols10and18, and the corresponding ketones11and19are presented.Endo‐5,exo‐6‐bis (chloromethyl)‐endo‐3‐chloro‐exo‐2‐norbornanol (16) andendo‐5‐(bromomethyl)‐exo‐6‐(chloromethyl)‐endo‐3‐chloro‐exo‐2‐norbornanol (17) were obtained by HCl‐ and, respectively, HBr‐addition toendo‐5,exo‐6‐bis (chloromethyl)‐exo‐2, 3‐epoxynorbornane (5). TheWagner‐Meerweinrearrangement was precluded in these reactions probably because of the formation of a relatively stable chloronium ion15arising from the participation of the 1,4‐chlorine atom of theendo‐5‐chloromethyl group in the heterolytic ring opening of the epoxide5.

The ‘naked’ fluoride anion (excess CsF in DMF or KF in DMF with 18‐crown‐6‐ether) permitted the selective elimination of 2 equivalents of HCl from16and yielded the chlorohydrin‐diene18.
Minecosid und Verminosid, zwei neue Iridoidglucoside aus Veronica officinalisL. (Scrophulariaceae)
Authors: Sticher Otto , Afifi‐Yazar Fatma Ü.
Published: December 2004

Minecoside and verminoside, two new iridoid glucosides from Veronica officinalis L. (Scrophulariaceae)

Two new esters of catalpol, minecoside (1) and verminoside (3), have been isolated from Veronica officinalis L. The structures of 1 and 3 have been determined on the basis of the spectral data as 6‐isoferuloylcatalpol and 6‐caffeeoylcatalpol, respectively.