bluuebunny/crossref_metadata_2025 huggingface dataset:
Studies on Debenzylation and Photolysis of 1‐Benzyl‐ and 1‐(β‐Phenethyl)‐1,2,3,4‐tetrahydroisoquinolines
Authors: Govindachari T. R. , Nagarajan K. , Rajeswari S. , Suguna H. , Pai B. R.
Published: December 2004

Debenzylation of 1‐(3‐benzyloxybenzyl)‐1,2,3,4‐tetrahydroisoquinolines 1, 6, 7 with hydrochloric acid and ethanol gave the corresponding phenolic isoquinolines 2, 8, 9 and tetrahydroprotoberberines 4, 12, 13. Compounds 2, 8, 9 on photolysis also gave, besides the expected noraporphines 3, 10, 11, the tetrahydroprotoberberines 4, 12, 13 [1–4] (Schemes 1 and 2). 6‐Benzyloxy‐1‐(5‐benzyloxy‐2‐bromo‐benzyl)‐1,2,3,4‐tetrahydroisoquinoline (27a) containing no methoxy or methylenedioxy groups either in ring A or C does not give protoberberine during debenzylation; but 28, the debenzylation product of 27a, on photolysis gives both the noraporphine 29 and the tetrahydroprotoberberine 30 (Scheme 6), proving that during debenzylation of 1‐(3‐benzyloxybenzyl)‐1,2,3,4‐tetrahydroisoquinolines containing additional methoxy or methylenedioxy groups, the necessary formaldehyde comes from the latter groups. During photolysis both the methoxy groups (methylenedioxy groups) and the C(3) atom of the tetrahydroisoquinoline moiety provide the formaldehyde. Veratrole under debenzylation and photolytic conditions and tetrahydroisoquinoline under the latter condition also give rise to formaldehyde (Schemes 8 and 10).

The novel bromohomoprotoberberine 43 along with 42 was formed during debenzylation of the 1‐phenethyl‐1,2,3,4‐tetrahydroisoquinoline 41. Photolysis of 42 yielded the novel nor‐homoaporphine 44, in addition to 43; the latter was debrominated to give the homoberbine 45.
Polymergebundene Cinchonaalkaloide als Katalysatoren in der Michael Reaktion
Authors: Hermann Kurt , Wynberg Hans
Published: December 2004

Polymer Bound Cinchona Alkaloids as Catalysts in the Michael Reaction

Three insoluble chiral polymers (6, 7 and 8) were prepared by functionalization of copoly(styrene −2% divinyl benzene) followed by reaction with quinine (9) or dihydrocupreine (10). Their utility as catalysts in the reaction between methyl indane‐1‐one‐2‐carboxylate (13) and 3‐butene‐2‐one (14) was studied. Table 1 (runs 2–6 and 8) shows that the Michael‐adduct 15 was formed in good chemical but low optical yields, independent of the chiral polymer used. These results are compared with those of the Michael reactions in the presence of the monomeric bases quinine (9), O‐acetyl‐quinine (11) and eucipine (12) (runs 1, 7 and 9).
Totalsynthese von (+)‐D‐Homoöstron‐3‐methyläther
Authors: Gutzwiller Jürg , Meier Werner , Fürst Andor
Published: December 2004

Total Synthesis of (+)‐D‐Homoestrone 3‐methyl ether

A novel total synthesis of (+)‐D‐homoestrone 3‐methyl ether (21) is described starting from (S)‐8a‐methyl‐3,4,8,8a‐tetrahydro‐2H, 7H‐naphthalene‐1,6‐dione (1) as a chiral synthon for the rings C and D. The key step involves alkylation of the derived 3 with m‐methoxyphenacyl bromide (4) as an AB‐building block to give the dioxo‐secosteroid 5. Hydrogenation of 5 affords the trans‐decalone 11. As by‐products the epimeric cis‐decalones 12 and 13 were characterized. Cyclization of 11 leads under kinetic control predominantly to the Δ9(11)‐tetraene 14. Catalytic hydrogenation of 14 and subsequent modification in ring D give the title compound 21. It was found that 14 and also the derived Δ8‐isomer 15a add hydrogen from the α‐face of the molecule to an extent of about 80%. The 8α‐D‐homoestrone derivatives 20a and 23 as well as the 9β‐isomers 19a and 22 were characterized.
Der Metabolismus des Retinoids Ro 10‐9359. Isolierung und Identifizierung der Hauptmetaboliten aus Plasma, Urin und Faeces des Menschen sowie aus der Galle der Ratte Synthese von drei Urinmetaboliten
Authors: Hänni Ralph , Bigler Felix , Vetter Walter , Englert Gerhard , Loeliger Peter
Published: December 2004

The Metabolism of the Retinoid Ro 10‐9359. Isolation and Identification of the Major Metabolites in Human Plasma, Urine and Feces Synthesis of Three Urinary Metabolites

After oral administration of therapeutic doses of the 3H‐labelled aromatic retinoic acid analog (retinoid) Ro 10‐9359 (ethyl all‐trans‐9‐(4‐methoxy‐2,3,6‐trimethyl‐phenyl)‐3,7‐dimethyl‐2,4,6,8‐nonatetraenoate) to humans 75 and 15% of the 3H‐dose were excreted within the first five days in the feces and the urine, respectively. Using chromatographic procedures including high pressure liquid chromatography 18 metabolites could be isolated from human urine. Their structures were elucidated by mass spectrometry and FT–1H‐NMR. spectroscopy. In these urinary metabolites the tetraene side chain of the parent compound Ro 10‐9359 is shortened. The radioactivity of the identified urinary metabolites accounted for about 11% of the dose. Three urinary metabolites were synthesized. The main part of the radioactivity excreted within the first five days in the feces consisted of unchanged drug (60% of the dose). A smaller (amount 15% of the dose) could not be identified. The unchanged drug and a major metabolite, the corresponding acid, were found in human plasma.

In an experiment with bile‐duct cannulated rats the radioactively labelled retinoid Ro 10‐9359 was injected intravenously. About 70% of the 3H‐dose was excreted in the bile, within the first 48 hours. The whole radioactivity of the rat bile consisted of polar metabolites. No unchanged drug could be found. After enzymatic hydrolysis of the bile conjugates three metabolites were isolated. The main metabolite (49% of the i.v. dose) was a conjugate of the corresponding acid of the parent drug, already found as free compound in human plasma. The other bile metabolites (9 and 7% of the i.v. dose) had an intact side chain, too.

An enterohepatic recycling of the bile metabolites was observed in the rat.
The Influence of Fasting on the Synthesis of Cholesterol, Squalene, Fatty Acids, and Ubiquinones in Liver, Small Intestine, and Kidney of Rats in vivo
Authors: Oswald  , Wiss Verena
Published: December 2004

The existence of a regulating site of the cholesterol synthetic pathway in rat liver located after the squalene formation is shown by a comparison of the incorporation of labelled acetate and mevalonate in vivo over a period from 7.5 minutes to several hours under fasting and non fasting conditions. The existence of such a regulating site becomes also evident by the influence of fasting on the incorporation of labelled squalene into the cholesterol of the liver.

It is assumed that enzymes acting between acetylcoenzyme A and mevalonate, e.g. the HMG‐coenzyme‐A reductase regulate the flux of substrate in direction squalene with the tendency to keep it constant. Such an assumption is in agreement with the observed minor influence of fasting on the squalene and ubiquinone synthesis.

It could be shown, that the cholesterol synthesis in the kidneys is regulated by the same mechanism as in liver, whereas such a regulation could be excluded in the small intestine.
Structure d'alcaloïdes indoliques doubles d'un type nouveau
Authors: Kunesch Nicole , Rolland Yves , Poisson Jacques , Majumder P. L. , (Née Raychaudhuri) R. Majumder , Chatterjee A. , Agwada Vincent C. , Naranjo Jorge , Hesse Manfred , Schmid Hans
Published: December 2004

The Structure of bis‐indoline alkaloids of a novel type

The structure of folicangine 4, a bis‐indoline alkaloid from the leaves of Voacanga africana, is obtained by correlation with voafolidine 3a and isovoafolidine 3b. It requires an ether bridge between the two parts of the molecule, as in subsessiline (amataine 5a). Subsessiline‐lactone, from the leaves of Voacanga thouarsii has structure 5b proved by correlation with 5a. The CD. curves of double‐indole alkaloids of vobtusine type are given (Table 3).
Intramolecular Stacking in Ternary Complexes Containing Uridine 5′‐Triphosphate, 2,2′‐Bipyridyl, and a Divalent Metal Ion
Authors: Fukuda Yutaka , Mitchell Paul R. , Sigel Helmut
Published: December 2004

The stability constants of the ternary complexes containing UTP, 2,2′‐bipyridyl (bipy), and Co2+, Ni2+, Cu2+, or Zn2+ (M2+) have been determined by potentiometric titrations (Table 1). Changes in stability are quantified by Δlog KM = log K–log K. For the Co2+, Ni2+, Cu2+, and Zn2+ systems Δlog KM is 0.10, −0.13, 0.36, and 0.15, respectively. All these ternary complexes are considerably more stable than would be expected on statistical grounds; indeed, for Co2+, Cu2+, and Zn2+, UTP4− binds more tightly to M (bipy)2+ than to M2+. An UV. difference spectroscopic study suggests that stacked adducts between bipyridyl and the pyrimidine moiety of uridine are formed. 1H‐NMR. studies of the bipy/uridine, bipy/UTP, and bipy/UTP/Zn2+ systems (Figs. 1 and 2) confirm the presence of stacking in the binary adducts and in the ternary complex. There is also evidence for the existence of the stacked protonated complex, Zn(bipy) (HUTP)−, with the proton at the γ‐phosphate group. The acidity constant of this ternary complex has been measured (Fig. 3). The observed stability enhancement of stacked adducts by the formation of a metal ion bridge is discussed (Fig. 4) and biological implications are indicated.
Tris (methylidene)‐cyclopropane (“[3]Radialene”) Part 1. Enthalpy of formation and strain energy
Authors: Bally Thomas , Baumgärtel Helmut , Büchler Ulrich , Haselbach Edwin , Lohr Wolfgang , Maier John P. , Vogt Jürgen
Published: December 2004

The enthalpy of formation of tris(methylidene)‐cyclopropane (“[3]radialene”, 1) has been determined as ΔH = 396 ± 12 kJ mol−1 from three fragmentation reactions of its molecular ion 1+ formed from 1 by photoionisation using synchrotron radiation. Comparative electron impact measurements using conventional mass spectrometry were also performed. A treatment of the latter data is described which leads to satisfactory agreement with the photoionization data. The experimental value of ΔH(1) is compared with various theoretical estimates. The strain energy of 1 is calculated to be 226.3 kJ mol−1. Linear extrapolation of this quantity from the increase of strain in passing from cyclopropane to methylidenecyclopropane yields 282.4 kJ mol−1. The discrepancy between these values, already predicted by Dewar and Baird ten years ago from theoretical calculations, is discussed on the basis of maximum overlap considerations. The enthalpy of formation of bis(methylidene)cyclopropane is predicted to be ΔH= 309 kJ mol−1.
Copper Catalysed Oxygenation of Bis (2‐pyridyl) methane and 6‐Methyl‐bis (2‐pyridyl)methane to the Corresponding Ketones
Authors: Urbach Fred L. , Knopp Ursula , Zuberbühler Andreas D.
Published: December 2004

The ligands (L) bis (2‐pyridyl) methane (BPM) and 6‐methyl‐bis (2‐pyridyl)methane (MBPM) form the three complexes CuL2+, CuL, and Cu2L2H with Cu2+. Stability constants are log K1 = 6.23 ± 0.06, log K2 = 4.83 ± 0.01, and log K (Cu2L2H + 2H2+ ⇌ 2 CuL2+) = −10.99 ± 0.03 for BPM and 4.56 ± 0.02, 2.64 ± 0.02, and −11.17 ± 0.03 for MBPM, respectively. In the presence of catalytic amounts of Cu2+, the ligands are oxygenated to the corresponding ketones at room temperature and neutral pH.

With BPM and 2,4,6‐trimethylpyridine (TMP) as the substrate and the buffer base, respectively, the kinetics of the oxygenation can be described by the rate law

with k1 = (5.9 ± 0.2) · 10−13 mol l−1 s−1, k2 = (4.0 ± 0.6) · 10−4 mol−1 ls−1, k3 = (1.1 ± 0.1) · 10−12 mol l−1 s−1, and k4 = (9 ± 2) · 10−14 mol l−1 s−1.
Tobacco Mosaic Virus as a Carrier for Small Molecules I. The preparation and characterization of a TMV/α‐melanotropin conjugate
Authors: Kriwaczek Verena M. , Eberle Alex N. , Müller Martin , Schwyzer Robert
Published: December 2004

The use of tobacco mosaic virus (TMV) covalently loaded with hormones or other small molecules for various purposes including receptor detection and isolation is proposed. The basic principle is that of cooperative affinity interactions involving (large) numbers of artificially introduced sites (e.g. hormones) of the modified virus on the one hand and membrane‐bound sites (e.g. receptors) of a cell or of a cellmembrane particle on the other. In order to test the feasibility of such TMV/hormone conjugates, TMV carrying about 500 molecules of a biologically active α‐melanotropin analogue was synthesized, and characterized by its aspect under the electron microscope, by its infectivity, its melanophore‐stimulating activity, and its reaction with antisera against α‐melanotropin. The observed hormonal activity is in accordance with the idea of cooperative affinity interactions.
A (1,3) Strain in cis‐ and trans‐5, 6‐dihydro‐4, 6‐dimethyl‐4H, 8H‐pyrido [3,2,1‐de]phenanthridin‐8‐ones
Authors: Nagarajan Kuppuswamy , Shah Rashmi K. , Fuhrer Hermann , Puckett Reginal T. , Narasimhamurthy Mathur R. , Venkatesan Kailasam
Published: December 2004

The stereochemistry of trans‐ and cis‐2, 4‐dimethyl‐tetrahydroquinolines, 6 and 7 were derived from 1H‐NMR. studies. These were converted respectively into trans‐ and cis‐5, 6‐dihydro‐4, 6‐dimethyl‐4H, 8H‐pyrido [3, 2, 1‐de]phenanthridin‐8‐ones 18 and 20 by a Pschorr reaction on the anthranilamides 10 and 15. Bromophenanthridones 19 and 21 were similarly prepared from bromoanthranilamides 12 and 17. Detailed 1H‐NMR. studies on 18 and 20 indicated axial disposition of the methyl groups at C(2) in both compounds in contrast to the situation in 6 and 7. This is presumably to avoid adverse CH3CO group interaction of the A (1, 3) type. The severity of this is gauged by the preference of 20 for a normally forbidding 1, 3‐diaxial orientation of two methyl groups. X‐ray crystallographic studies on 19 and 20 confirm the stereochemical assignments.
[2+2]‐Cycloadditionen und ‐Cycloreversionen in Radikalanionen. Eine ESR.‐spektroskopische Beschreibung am Beispiel 2,2′‐disubstituierter Biphenyle
Authors: Müllen Klaus , Huber Walter
Published: December 2004

[2+2]‐Cycloadditions and ‐cycloreversions in radical anions. An ESR. spectroscopic study for 2,2′‐disubstituted diphenyl derivatives

The radical anions derived from the polycyclic olefins 1, 2 and 3 are shown by ESR. spectroscopy to undergo [π2+π2]‐cycloaddition reactions even at low temperatures. Similarly, facile cleavage by [σ2+σ2]‐cycloreversion processes is observed for the radical anions of the corresponding cyclobutane species. This reactivity, which is in marked contrast with the thermal stability of the neutral parent compounds, is discussed taking into account the molecular geometry and the spin density distribution.
The Binding of Flavins by Apoflavodoxins from Peptostreptococcus elsdenii and Azotobacter vinelandii as Studied by Temperature‐Jump Technique
Authors: Gast Robert , Müller Franz
Published: December 2004

The binding of various flavins by apoflavodoxins from P. elsdenii and A. vinelandii has been studied by the temperature‐jump technique using fluorescence detection. P. elsdenii apoflavodoxin interacts only with flavins possessing 5 carbon atoms in the N(10) side chain and a terminal phosphate group. Employing a wide range of concentrations of deoxy‐FMN

Flavin = 3,4‐dimethyl‐lO‐substituted isoalloxazine = 3,4‐dimethyl‐ lO‐substituted‐2,3,4,10‐tetrahydro‐benzo[g]‐pteridine‐2,4‐dione; FMN = riboflavin‐5′‐monophosphate.

and apoflavodoxin only one relaxation process was observed, indicating a one‐step binding mechanism. With native flavodoxin no relaxation could be observed.

The kinetic parameters of the interaction of A. vinelandii apoflavodoxin with various flavin analogs (Structure I) have also been investigated. The interaction between apoflavodoxin and flavin derivatives carrying an ionizable, terminal functional group on the side chain becomes very weak when the number of the side chain carbon atoms is decreased below 4. This observation is interpreted in terms of repulsive forces due to negatively charged amino acid residues located in the flavin side chain binding region of the apoflavodoxin. All complexes studied revealed only one relaxation process. This observation is in contradiction with published results [10]. The published traces are instrumental artifacts.
A Short Synthesis of 3,5‐Dimethyl‐1,2,4‐trithiolane
Authors: Dubs Paul , Joho Martin
Published: December 2004

A short synthesis of 3,5‐dimethyl‐1,2,4‐trithiolane (1), a well‐known constituent of processed meat, is described.
1, 4, 5, 6‐Tetrahydro‐ν‐tetrazin‐Derivate
Authors: Seebach Dieter , Dach Rolf , Enders Dieter , Renger Bernd , Jansen Martin , Brachtel Gerold
Published: December 2004

1, 4, 5, 6‐Tetrahydro‐ν‐tetrazin‐Derivate

The title compounds 2 and 13 are readily available from α‐lithiated N‐alkyl‐nitrosoamines 1 (see Tables 1 and 2) which decompose at − 73° to yield the N‐oxides 2. The ESR. spectra of two derivatives 1 are recorded (Fig. 1), and tentative mechanisms are proposed for the head to head dimerizations (la‐ 3‐ 4‐ 5‐ 2a and Scheme 1). Coupling of lithionitrosoamines with iodine (‐6) and alternative decomposition routes of representatives of this class of organometallics with special substitution [equations (2)‐(5)] are reported.

The structures of the tetrazines are established by spectroscopic data [ESCA] (Fig. 2), IR., UV., 1H‐ (cf. Fig. 9) and 13C‐NMR., PE. (Scheme 2), by an X‐ray analysis of 2a (Fig. 4‐8 and Table 3), and by the chemical reactions. The crystal structure of 2a is a twisted boat with non planar terminal nitrogen atoms which reflects the electron repulsion in the 4‐atom‐6‐electron NNNN‐system. Comparisons are made with 2‐tetrazenes, the open chain analogues of 13, wherever possible. Raney‐Ni reductions of 2 or 13 gives diamines 14 to which is assigned the d, l‐configuration through the 1H‐NMR. spectra of the aminals 7 and 15. Neither the oxides 2 nor the tetrazines 13 undergo cycloaddition reactions [equation (6) and Section 4].

Compound 2a is dimerized to the bis (nitrosoamino)‐2‐tetrazene 18 by treatment with acid, ZnII, CuI or iodomethane. 2a is oxidized at nitrogen to the ethylene diamine derivative 6a (through 20, with H2O2), or at the CH2‐groups of the ring to give oxo‐N‐oxide 21 (with MnO2 or the ring contracted oxo‐tetrazoline‐N‐oxide 22 (with KMnO4).

Pyrolysis or photolysis of the dimethyl tetrahydrotetrazine 13a furnishes the trimer 26 of N‐methylimine, but no diazetidine 27. Silver and mercury complexes 29 are obtained from 13a, while Cr(CO)5. THF does not furnish a complex as with azocompounds, but rather replaces N2 in 13a by CO (→ 28). Oxidation with permanganate converts 13a into the oxalic acid derivative 30 with unchanged tetrazine structure.
Cyclooct‐1‐en‐5‐yne. Preparation, spectroscopic characteristics and chemical reactivity
Authors: Leupin Werner , Wirz Jakob
Published: December 2004

Cyclooct‐1‐en‐5‐yne (3) has been obtained as an isolable, but highly reactive hydrocarbon by oxidation of cyclooct‐5‐ene‐1, 2‐dihydrazone with lead tetraacetate (Scheme 2). Information regarding the structure and conformational mobility of 3 has been gained from the analysis of its 1H‐ and 13C‐NMR. spectra and was found to agree with the results of force field calculations. Photolysis (206 nm) of 3 in solution has induced cleavage to butatriene and butadiene. The first band in the photoelectron spectrum of 3 (Iv 9.10 eV) is attributed to ionization from a rather delocalized orbital with predominant weight of the double bond p‐AO's. Nevertheless, the high reactivity of 3 stems from the strained triple bond as evidenced by the reaction products obtained by pyrolysis, oxidation, Diels‐Alder addition, and 1, 3‐dipolar addition (Scheme 4).
Synthesen von Moniliformin, einem Mycotoxin mit Cyclobutendion‐Struktur
Authors: Belluš Daniel , Fischer Hanspeter , Greuter Hans , Martin Pierre
Published: December 2004

Syntheses of Moniliformin, a Mycotoxine with a Cyclobutenedione Structure

Six different routes to 3‐hydroxy‐3‐cyclobutene‐1, 2‐dione (4), the free acid of the mycotoxine Moniliformin (=alkali salt of 4) are described. A common feature of all pathways is the synthesis of cyclobutanes having the oxidation level 6. Moniliformin precursors which are easily transformed to 4 by acid catalysed hydrolysis include [2+2]‐cycloadducts of ketene with tetraalkoxy‐olefins, 3,4,4‐trialkoxycyclobutenes, derivatives of polyfluorinated cyclobutenes, the brominated [2+2]‐cycloadduct of ethyl vinyl ether and dichloroketene, tetrabromocyclobutanone, [2+2]‐photocycloadducts of dichlorovinylenecarbonate with dichloroethylenes, and the dimer of chloroketene. The most convenient synthesis via the [2+2]‐cycloadduct of tetraethoxyethylene and ketene (14b) is reported in detail and produces 4 in four simple steps in 57% overall yield. In addition, two new syntheses of squaric acid (56) are described.
Molluscicidal saponins from cornus florida L.
Authors: Hostettmann Kurt , Hostettmann‐Kaldas Maryse , Nakanishi Koji
Published: December 2004

The molluscicidal principle of Cornus florida L. (Cornaceae) has been isolated from the methanolic bark extract by droplet counter‐current chromatography (DCC). The structure of the active compounds has been determined as sarsapogenin‐O‐β‐D‐xylopyranosyl‐(1 → 2)‐β‐D‐galactopyranoside (2) and sarsapogenin‐O‐β‐D‐glucopyranosyl‐(1 → 2)‐β‐D‐galactopyranoside (3).
Radical Ions in the Pentalene Series. Part. I. 1,3,5‐tri‐t‐butylpentalene
Authors: Fürderer Peter , Gerson Fabina , Hafner Klaus
Published: December 2004

The ESR. spectra of the radical anion and cation of 1, 3, 5‐tri‐t‐butylpentalene (II) have been reexamined under higher resolution. With the assistance of the ENDOR. technique, the coupling constants of all protons in II⊖. and II⊖. could be determined. The experimental data agree satisfactorily with the values predicted by the simple MO model which suggests that the π‐spin distributions in II⊖. and II⊖. should not strongly differ from those in the corresponding radical ions of parent pentalene (I). As in the case of other non‐alternant hydrocarbons, the proton coupling constants for II⊖. are very sensitive to experimental conditions, due to the association of the radical anion with its counterion. Spectra of II⊖. taken at low temperatures (down to 133 and 163 K for ESR. and ENDOR., respectively) have not revealed specific line‐broadening which could arise from the bond shift between the two Kekulé‐structures of pentalene.
Cob(I)alamin als Katalysator 2. Mitteilung [1]. Reduktion von gesättigten Nitrilen in wasserfreier Lösung
Authors: Fischli Albert
Published: December 2004

Cob (I)alamin as Catalyst 2. Communication [1]. Reduction of Saturated Nitriles in Anhydrous Solution

Using cob (I)alamin as homogenous catalyst in glacial acetic acid saturated nitriles are reduced following the path of a reductive amination. The results prove the presence of an intermediate imine during the reduction of saturated nitriles with cob (I)alamine.
Zum stereochemischen Verlauf der elektrophilen Substitution an CH‐Gruppen in α‐Stellung zum N‐Atom behinderter Amide Vorläufige Mitteilung
Authors: Seebach Dieter , Wykypiel Werner , Lubosch Winfried , Kalinowski Hans‐Otto
Published: December 2004

On the Sterochemical Course of Electrophilic Substitution at CH Groups in α‐Position to the N‐Atom of Hindered Amides

It is shown by 1H‐NMR. analysis of the aminoalcohol derivatives 4b and 4c that the lithiation/hydroxyalkylation with acetone of 1‐nitroso‐and 1‐(2,4,6‐triiso‐propylbenzoyl)‐4‐phenyl‐piperidine leads to configurationally different products. The assigned cis and trans configuration of the substituents in 4b and 4c, respectively, is compatible with the electronic structures 2 and 1, respectively, which were previously proposed for the lithio‐derivatives 3 involved in such transformations.
Efficient Conversion of Esters to α‐Trimethylsilylketones. Preliminary communication
Authors: Demuth Martin
Published: December 2004

Secondary and tertiary carboxylic methyl or ethyl esters (2a‐c) were converted with trimethylslylmethyllithium (3a‐c) in high yields. Under identical reaction conditions the primary esters 2d,e gave 3d, e in lower yields. Since the trimethylsilyl (TMS) group α to a ketone is known to undergo facile elimination under a variety of reaction conditions, the method also constitutes a highly versatile ester to methylketone sequence.
A Novel Entry to the Eremophilane and Valencane Sesquiterpenes via a Stereoselective Intramolecular Diels‐Alder Reaction. Preliminary communication
Authors: Näf Ferdinand , Decorzant René , Thommen Walter
Published: December 2004

A general stereoselective entry to racemic eremophilane and valencane sesquiterpenes, via a common key intermediate and using an intramolecular Diels‐Alder reaction, is described.
Planarization of Tetracoordinate Carbon Atom. Synthesis of 13‐oxa‐14‐oxo‐pentacyclo [5.5.2.1.04,15010,15]pentadecane, a bridged ‘tetraquinacane’ preliminary communication
Authors: Keese Reinhart , Pfenninger Armin , Roesle Alex
Published: December 2004

Structural aspects of planoid deformation of tetracoordinate carbon atom, particularly those in annulenes with central carbon atom are discussed. [12] Annulene 11 with central carbon atom is proposed as compound with strong planoid deformation around the internal carbon centre. The synthesis of a saturated precursor 15 is described.
The Reaction of Patchoulol with Lead Tetraacetate, a Regiospecific Fragmentation
Authors: Thomas Alan F. , Ozainne Michel
Published: December 2004

Patchoulol (1) forms 2,2,6,8‐tetramethylbicyclo [5.3.1]undec‐7‐en‐3‐one (5) with lead tetraacetate. This ketone undergoes acid‐catalyzed cyclization to 2,6,6,10‐tetramethyltricyclo [5.3.1.01,5]undec‐9‐en‐5‐ol (10), and is reduced to 2 stereoisomeric alcohols with lithium aluminium hydride. One of these alcohols 8 is readily dehydrated with cyclization to 2,6,6,10‐tetramethyltricyclo [5.3.1.01,5]undec‐9‐ene (12) and a double bond isomer 13, longer treatment with acid resulting in a Wagner‐Meerwein rearrangement to a mixture of two 1,3,7,7‐tetramethyltricyclo [6.2.1.02,6]‐undecenes (19 and 20), isomeric with β‐patchoulene (23). The other alcohol 7 with p‐toluenesulfonic acid forms the cyclic ether, 1,3,7,7‐tetramethyl‐11‐oxatricyclo‐[4.4.1.12,8]dodecane (15).
Totalsynthese von natürlichem α‐Tocopherol 3. Mitteilung. Aufbau der Seitenkette mit (−)‐(S)‐2‐Methyl‐γ‐butyrolacton als zentralem Baustein
Authors: Zell Reinhard
Published: December 2004

Total Synthesis of Natural α‐Tocopherol

(−)‐(S)‐2‐Methyl‐γ‐butyrolactone (2) represents a versatile chiral C5‐synthon. It serves as key intermediate in one of the syntheses of certain isoprenoid derivatives such as (R)‐dihydrocitronellol, (3R, 7R)‐hexahydrofarnesol and vitamin E of natural configurations. Their syntheses are described in detail.
The Structure of the Alkaloid Peduncularine. Communication no. 172 on organic natural products
Authors: Ros Hans‐Peter , Kyburz Rolf , Preston Nigel W. , Gallagher Rex T. , Bick I. Ralph C. , Hesse Manfred
Published: December 2004

The revised structure 1 is put forward for peduncularine, the main alkaloid of Aristotelia peduncularis (Labill.) HOOK. F. (Elaeocarpaceae), on the basis of its spectroscopic properties and those of its degradation products, the Hofmann base 3 and the hydrogenation product 4. Structure 1 represents the relative configuration of the alkaloid.

Peduncularine belongs to the class of indole alkaloids with a monoterpene unit as the aliphatic portion. To our knowledge it constitutes the first example in which an isopropyl group has become detached from the terpene unit and occurs as a substituent on nitrogen.
Studies on Radical Cations, II. Principles Involved in their Electrocyclic Reactions
Authors: Haselbach Edwin , Bally Thomas , Lanyiova Zuzana
Published: December 2004

Electrocyclic reactions connecting radical cations are compared with those of the parent neutrals. Principles governing over‐all reactivity and stereoselectivity of the open‐shell processes are discussed.
Studies on Radical Cations, III. The Type C Valence‐Isomeric System Quadricyclane Radical Cation/Norbornadiene Radical Cation
Authors: Haselbach Edwin , Bally Thomas , Lanyiova Zuzana , Baertschi Peter
Published: December 2004

The previously discussed principles involved in electrocyclic reactions of openshell ions are exemplified for a type C system, the radical cation couple quadricyclane+ (Q+)/norbornadiene+ (NBD+). Exhaustive calculations (MINDO/3) for the various states of the ions support the general predictions for such types of systems. The barrier of interconversion Q+ → NBD+ is estimated to be significantly lower than that for the corresponding neutrals. Experimental support to this prediction is obtained by γ‐irradiation of Q or NBD in an electron scavenging matrix. In both cases only NBD+ is observed, indicating that Q+ is not stable at 77 K. Previous observations and propositions referring to the system Q+/NBD+ are discussed in view of the present findings.
Synthesis of Xanthone‐O‐Glycosides. II.. Synthesis of 1‐O‐β‐glycosides
Authors: Chari V. Mohan , Klapfenberger Rosalinde , Wagner Hildebert , Hostettmann Kurt
Published: December 2004

Several naturally occurring xanthone‐1‐O‐glycosides have been synthesized in order to study monoamine oxidase (MAO) inhibition structure‐activity relationships. The syntheses also confirmed the structures as 1‐β‐D‐glucosyloxy‐3‐hydroxy‐5‐methoxyxanthone (Canscora decussata SCHULT.), 1‐O‐β‐primeverosyl‐3, 7, 8‐trimethoxyxanthone (decussatin‐1‐O‐primeveroside, Gentiana verna L.) and 1‐O‐β‐primeverosyl‐3, 8‐dimethoxy‐7‐hydroxyxanthone (gentiacaulein‐1‐O‐β‐primeveroside, Gentiana verna L.).
Identification et synthèse de nouveaux depsides isolés de la mousse de chêne (Evernia Prunastri (L.) ACH.). 4e Communication
Authors: Nicollier Gilles , Rebetez Michel , Tabacchi Raffaele
Published: December 2004

Identification and synthesis of new depsides isolated from oakmoss (Evernia Prunastri (L.) ACH.)

Lecanoric acid 5 and 4 new depsides have been isolated from oakmoss (Evernia Prunastri (L.) ACH.) extracts by means of silicagel column chromatography. Various spectral methods including 13C‐NMR. were used in determining the structure of 4,2″‐O‐methylgyrophoric acid (1), lecanoric acid (5), 2′‐O‐methylevernic acid (2), 3′‐methylevernic acid (3) and methyl 3′‐methyllecanorate (4).
Dérivés diglycosyliques. Communication préliminaire
Authors: Tronchet Jean M. J. , Habashi Ford , Martin Olivier R. , Bonenfant Alain P. , Baehler Bruno , Zumwald Jean‐Bernard
Published: December 2004

Diglycosyl Derivatives. Preliminary communication

Novel types of diglycosyl compounds, some of them bearing a resemblance to natural di‐ or tri‐saccharides are described: a diglycosyldiyne (1), a diglycosylthiophene (2), a diglycosylaziridine (3), a diglycosyldioxolane (4), as well as six C,N‐diglycosylnitrones, 9b–9f and 14. These C,N‐diglycosylnitrones, on treatment with an acetylenic Grignard reagent, led to the expected acetylenic diglycosyl‐hydroxylamine 11, whereas diglycosylisoxazolines (f. ex. 10) were obtained when these nitrones underwent 1,3‐dipolar cycloaddition to acetylenic compounds.
Additionsreaktionen von 3‐Dimethylamino‐2,2‐dimethyl‐2H‐azirin an Phenylisocyanat und Diphenylketen
Authors: Mukherjee‐Müller Gabriele , Heimgartner Heinz , Schmid Hans
Published: December 2004

Addition Reaction of 3‐Dimethylamino‐2,2‐dimethyl‐2H‐azirine with Phenylisocyanate and Diphenylketene

3‐Dimethylamino‐2,2‐dimethyl‐2H‐azirine (1a) reacts with carbon disulfide and isothiocyanates with splitting of the azirine N(1), C(3)‐double bond to give dipolar, fivemembered heterocyclic 1:1 adducts. In some cases, these products can undergo secondary reactions to yield 1:2 and 1:3 adducts. In this paper it is shown that the reaction of 1a with phenylisocyanate also takes place by cleavage of the N(1), C(3)‐bond, whereas with diphenylketene N(1), C(2)‐splitting is observed.

The reaction of 1a and phenylisocyanate in hexane at room temperature yields the 1:3 adduct 2 in addition to the trimeric isocyanate 3 (Scheme 1). A mechanism for the formation of 2 is given in Scheme 5. Hydrolysis experiments with the 1:3 adduct 2, yielding the hydantoins 4–6 and the ureas 7 and 8 (Schemes 3 and 5), show that the formation of this adduct via the intermediates d, e and f is a reversible reaction.

The aminoazirines 1a and 1b undergo an addition reaction with diphenylketene to give the 3‐oxazolines 14 (Scheme 8), the structure of which has been established by spectral data and oxidative degradation of 14a to the 3‐oxazolin‐2‐one 15 (R1  R2  CH3, Scheme 9).
Beitrag zum Reaktionsmechanismus der Synthese von Seychellen [1]
Authors: Fráter György
Published: December 2004

New Mechanistical Details Concerning the Synthesis of Seychellen [1]

In the last step of our synthesis of Seychellen (2) [1], the solvolysis of 1, only one side‐product was formed, namely 3 (Scheme 1). Now the structure of 3 has been elucidated, mainly by spectroscopic studies of its derivatives 7 and 9 (Scheme 2). In order to differentiate between two different solvolytic pathways from 1 to 3 (see Scheme 1 and 3) d3‐1 was prepared. Solvolysis of d3‐1 proved the mechanism shown in Scheme 1. Solvolysis of 1 and of 2‐epi‐1, respectively, furnished the same product distribution, which makes a common intermediate a very probable. In both cases 10 is an intermediate, which is slowly converted into 2 and 3. 2‐epi‐1 was prepared from 1 (Scheme 5).

Kinetic measurements with 1, d3‐1 and 2‐epi‐1 are also in agreement with the mechanism drawn in Scheme 4: k1(72°) = (5,2±0,5) · 10−5 sec−1, k1(H)/k1(D)(72°) = 1,4±0,15; k2(H)/k4(H) = 0,66 and k2(H)/k2(D) = 2,2 if k4(H) ≈ k4(D) is assumed.
Spiro‐β‐lactame durch [2+2]‐Cycloaddition von Ketenen an Iminolactone
Authors: Roth Martin
Published: December 2004

Spiro‐β‐lactams from [2+2]‐Cycloaddition of Ketenes to Iminolactones

Iminolactones (‘Isoimides’) derived from maleic anhydride and amines are shown to react with various ketenes in a [2+2]‐cycloaddition mode. Either preformed ketenes or the combination acid chloride/tertiary amine can be used as reagent. The reaction products have been assigned the spiro‐β‐lactam structure. Unsubstituted ketene is inert under the reaction conditions. It is possible to synthesize the spiro‐β‐lactams in a one‐pot procedure, starting from a mixture of maleic anhydride/amine and excess dialkylketene.
Medium Effects on C,C‐Bond Cleavage in the Alcohol Oxidation with Chromic Acid
Authors: Müller Paul , Blanc Jacky
Published: December 2004

The C,C‐bond cleavage which occurs during chromic acid oxidation of t‐butylphenylmethanol (1) and 1,2‐diphenylethanol (2) to the extent of up to 67% is reduced to 3% for 1 and 13% for 2 when the reaction is run in acetone, and totally suppressed upon co‐oxidation of the alcohols 1 and 2 with oxalic acid. Similarly, the yield of 7‐norbornanone obtained from 7‐norbornanol (7) is raised in going from acetic acid (24%) to acetone (41%) and approaches 100% in the co‐oxidation. With the co‐oxidation 5‐endo‐bicyclo [2.1.1]hexanol (3) is converted to the corresponding ketone in 54% yield. Mechanistic implications of these results are discussed.
On the Misleading Interpretation of the Properties of the f‐Electron Elements
Authors: Fidelis Irena
Published: December 2004

The aim of the paper is to elucidate the problem of the regular changes in the properties of f‐elements represented by the double‐double effect. It is pointed out that because of the half‐filled shell and double‐double effects the f‐element properties cannot be plotted as a linear function of the L‐quantum number, as suggested by Sinha [1][2].
An Answer to the Article ‘On the Misleading Interpretation of the Properties of the f‐Electron Elements’
Authors: Sinha Shyama P.
Published: December 2004

The position of the ‘Inclined W theory’, i.e., the linear correlation of the properties (Pi) of the lanthanide and the actinide ions with their ground state total orbital angular quantum numbers (L), Pi = wiL + ki, where wi and ki are the slopes and intercepts of the least squares lines, is made clear. The position of gadolinium is ambivalent, and it can be a common point for the symmetric ‘Inclined W plots’ or it may either belong to the second or the third tetrad depending on the system investigated. The propionate and the isobutyrate systems are used to elucidate the ‘Inclined W concept’. The ‘Inclined W parameters’ for the solvent extraction of the lanthanides with PMBP ligand have been calculated.
Photoreaktionen von 1‐Alkylbenztriazolen
Authors: Märky Michael , Schmid Hans , Hansen Hans Jürgen
Published: December 2004

The irradiation of benzotriazoles (cf. Scheme 2) with light of 225–325 nm in protic and in aromatic solvents was investigated. In aqueous 0.1N H2SO4 benzotriazole (5) and 1‐methyl‐benzotriazole (6) yielded 2‐amino‐ and 2‐methylaminophenol (25 and 26), respectively (Scheme 3). In 2‐propanol 6, 5‐chloro‐ and 6‐chloro‐1‐methyl‐benzotriazole (14 and 15) were reduced to N‐methylaniline, 4‐chloro‐ and 3‐chloro‐N‐methyl‐aniline (27, 28 and 29), respectively (Scheme 4). When the benzotriazoles were irradiated in aromatic solvents only C, C coupling products were observed (cf. Scheme 6 and Tables 1–4). It is of importance that 5‐chloro‐1‐methyl‐benztriazole (14) when decomposed photolytically in benzene solution yielded only 4‐chloro‐2‐phenyl‐N‐methyl‐aniline (49) and its 6‐chloro isomer only 5‐chloro‐2‐phenyl‐N‐methyl‐aniline (50), i.e. the intervention of benzo‐1H‐azirine intermediates (e.g. 53, Scheme 8) can be excluded. The substitution patterns which are observed when 6 is irradiated in toluene, anisole, fluoro‐, chloro‐, bromobenzene and benzonitrile (cf. Table 4) can best be explained by assuming that 6, after loss of nitrogen, forms a diradical intermediate in the singlet state with highly zwitterionic character. 1‐(1′‐Alkenyl)‐benzotriazoles (cf. Table 7) form on irradiation in cyclohexane solution indoles by intramolecular ring closure of the diradical intermediate and proton shift. After irradiation of 1‐decyl‐benzotriazole (8) in a glassy matrix at 77K a 7‐line ESR. spectrum characteristic of a triplet radical is observed. This is in agreement with the fact that the lowest lying state of intermediates of type 2 (Scheme 1) should be a triplet state (cf. [21] [26]).
Macrocycles by Olefination of Dialdehydes with 1,3‐Bis(dimethylphosphono)‐2‐propanone
Authors: Büchi George , Wüest Hans
Published: December 2004

Conjugated cyclic divinyl ketones containing fifteen and seventeen membered rings have been prepared in a single step by condensation of 1,3‐bis (dimethylphosphono)‐2‐propanone (10) with the dialdehydes 14, 17, 20, and 42 in the presence of hydrogencarbonate in aqueous t‐butyl alcohol at reflux without using high dilution techniques. The more highly unsaturated aldehydes give better yields and ketones 34 and 36, or mixtures of the two, were transformed to muscone (1) and Exaltone® by standard procedures. Civetone (2) was prepared by hydrogenation of 43 in pyridine solution. Dienone 29 appears to be the first α, β‐unsaturated ketone in which one of the β‐vinyl proton resonates at higher field than the corresponding α‐proton.
Crocetin‐dialdehyde from Coleus forskohlii BRIQ., Labiatae
Authors: Tandon Jai Shanker , Katti Seturam Bandacharya , Rüedi Peter , Eugster Conrad Hans
Published: December 2004

Aus den Wurzeln der im Titel genannten Labiate wurde Crocetin‐dialdehyd (8,8′‐Diapo‐carotin‐8,8′‐dial) (1), C20H24O2, isoliert. Chromatographisch wurde diese Verbindung auch in den oberirdischen Teilen dieser Pflanze nachgewiesen.
Einfache Synthese von 6‐[4‐Methyl‐3‐cyclohexen‐1‐yl]‐hept‐5‐en‐2‐on, einer Vorstufe für α‐Bisabolen und dessen Isopropenyl‐Isomers. Terpene und Terpen‐Derivate, 10. Mitteilung
Authors: Becker Manfred , Weyerstahl Peter
Published: December 2004

Simple Synthesis of 6‐[4‐Methyl‐3‐cyclohexen‐1‐yl]‐5‐hepten‐2‐on, a Precursor of α‐Bisabolene and Its Isopropenyl Isomer

The alcohol 14 reacts with vinyl resp isopropenyl ether by Claisen rearrangement to give the aldehyde 16/17 resp. the ketone 3/4. Contrary to other reports this separable (E/Z)‐mixture also occurs as a result of the synthesis following the pathway 7 → 8/9 → 10/11 → 12/13 (see also [2]). The bisabolene isomers 5 resp. 6 are obtained by reaction of 3 resp. 4 with methylidene triphenyl phosphorane. A mixture of 1 and 5. however, is formed from 3 via the alcohol 18 and its acetate 19. Likewise 4 reacts via 20 and 21 to give a (2/6)‐mixture.
Stereospezifische Synthese von (+)‐(3R, 4R)‐4‐Methyl‐3‐heptanol, das Enantiomere eines Pheromons des kleinen Ulmensplintkäfers (Scolytus multistriatus)
Authors: Fráter György
Published: December 2004

Stereospecific Synthesis of (+)‐(3R, 4R)‐4‐Methyl‐3‐heptanol, the Enantiomer of a Pheromone of the Smaller European Elm Bark Beetle (Scolytus multistriatus)

Reduction of 2 with actively fermenting baker's yeast gave (−)‐3. Stereospecific alkylation [3] of (−)‐3 with propyl iodide furnished ethyl (+)‐(2R, 3R)‐2‐propyl‐3‐hydroxypentanoate ((+)‐4, 58%) which was converted to the tetrahydropyranyl ether (−)‐5, then the alcohol 6, the p‐toluenesulfonate 7 and the thiophenyl ether 8 to give the title compound (+)‐1. The latter consisted of 97% of the threo‐ and 3% of the erythro‐isomer. The above synthesis also correlates the absolute configuration of (−)‐(R)‐3 with that of (+)‐(R)‐citronellic acid (see [2]).
1,7‐Trimethylenenorbornane. A novel member of the ‘adamantaneland’. Preliminary communication
Authors: Jäggi Franz Josef , Ganter Camille
Published: December 2004

A synthesis of the novel C10H16 hydrocarbon 1,7‐trimethylenenorbornane (13), one of the 19 members of the adamantane family, is described.
Metabolic Transformation of (3R, 4R)‐Δ1(7)‐Tetrahydrocannabinol by a Rat Liver Microsomal Preparation
Authors: Binder Michael , Barlage Uwe
Published: December 2004

The metabolism of the non‐psychotropic cannabinoid (3R, 4R)Δ1(7)‐tetrahydrocannabinol (1) (=Δ 1(7)‐THC) was investigated in a rat liver microsomal preparation. The metabolites obtained from the incubation mixture were separated, purified and identified by 1H‐NMR. spectroscopy and combined gas‐liquid chromatography/mass spectrometry. Metabolites 3–10 are derived from Δ1(7)‐THC (1) by mono‐hydroxylation in the isoprenoid moiety or the side chain of the molecule. Metabolites 11–16 are hydroxylated in the isoprenoid ring and the side chain simultaneously. The third group, metabolites 18–22, is derived from the 1,7‐epoxide 17 by hydrolysis of the oxirane ring, three of these metabolites bearing additional hydroxyl‐groups in the isoprenoid part or the side chain. The mass spectra of the metabolites are discussed in detail and a new rule for the fragmentations of tetrahydrocannabinols is presented.
Eine neue Synthese von 8‐Hydroxy‐2‐methyl‐1,2,3,4‐tetrahydroisochinolin
Authors: Gray Robert W. , Dreiding Andréa S.
Published: December 2004

A new Synthesis of 8‐Hydroxy‐2‐methyl‐1,2,3,4‐tetrahydroisoquinoline

Vilsmeier formylation of N‐[2‐(3,5‐dimethoxyphenyl)ethyl]‐trifluoroacetamide (5) yielded the aldehyde 6, which under mild basic conditions was hydrolyzed to 7 and cyclized to 6,8‐dimethoxy‐3,4‐dihydroisoquinoline (3). Methylation of 3 and reduction of the double bond in 10 afforded 6,8‐dimethoxy‐2‐methyl‐1,2,3,4‐tetrahydroisoquinoline (11). The methoxyl group at C(6) was selectively demethylated and the free hydroxyl group in 12 was phosphorylated to give 13. Reduction of the latter with potassium in liquid ammonia yielded 8‐methoxy‐2‐methyl‐1,2,3,4‐tetrahydroisoquinoline (2), which was demethylated to the title compound 1.
Perkow Reaction Induced C,C‐Bond Formation
Authors: Winkler Tammo , Bencze William L.
Published: December 2004

The reaction of a cinnamoyl chloride with excess trimethyl phosphite gives a substituted 1,5‐hexadiene, in which C,C‐bond formation has taken place between the β‐C‐atoms of the two α, β‐unsaturated carbonyl moieties.
Photochemische Reaktionen. 107. Mitteilung. Zur Photochemie offenkettiger 2,6‐bzw. 2,7‐Dien‐Carbonylverbindungen
Authors: Yoshioka Michikazu , Ishii Keitaro , Wolf Hans Richard
Published: December 2004

The Photochemistry of Open‐Chained 2,6‐ or 2,7‐Dien‐Carbonyl Compounds

On 1n, π*‐excitation (λ > 347 nm) citral (5) and the methyl ketone 10 isomerize to compounds A (7, 19) and B (6, 20), whereas the phenyl ketone 11 changes into the isomer 24 of type E. Evidence is given that the conversions to A and B may arise from the 3n, π*‐state of the 2,6‐diene‐carbonyl compounds.

On 1n, π*‐excitation (λ = 254 nm) 5 and 10 yield the isomers A (7, 19) and D (18, 22), but no products of type B. Furthermore, conversion of 10 to the isomer 21 of type C is observed.

Selective 1n, π*‐excitation (λ = 254 nm) as well as selective 1n, π*‐excitation (λ > 347 nm) of the 2,7‐diene‐carbonyl compounds 12 and 13 give rise to isomerization to the compounds F (25, 28), exclusively. The intramolecular [2 + 2]‐photocycloadditions are shown to be triplet processes.

UV.‐irradiation (λ > 280 nm) of compounds F (25, 28) furnishes the isomeric products G (26, 29) which photoisomerize to oxetanes of type H (27, 30).
Saponins with Molluscicidal Activity from Hedera helixL
Authors: Hostettmann Kurt
Published: December 2004

Four triterpenoid saponins (1–4) have been isolated from the berries of Hedera helix L. (Araliaceae) by droplet counter‐current and preparative liquid chromatography. The structures have been established by FD./MS. and 13C‐NMR. spectroscopy. The isolated compounds were found to possess strong molluscicidal activity against the bilharziasis‐transmitting snail Biomphalaria glabrata. Saponin 4, identified as hederagenin 3‐O‐β‐D‐glucopyranosyl‐(1 → 2)‐β‐D‐glucopyranoside, is a new natural product.
Neue Wege zu 1H‐ und 2H‐Pyrrolen
Authors: Pfoertner Karl‐Heinz , Foricher Joseph
Published: December 2004

New Routes to 1H‐ and 2H‐Pyrroles

A synthesis of 1H‐pyrroles is described starting with pyridine analogues of chalcones and involving the reaction of acetic anhydride with 1‐pyrroline‐1‐oxides. Another route leads from 1‐pyrrolines to 2 H‐pyrroles via bromination with N‐bromosuccinimide and subsequent dehydrobromination in dimethylformamide.
Synthese von Diaza‐octahydroporphinato‐kobalt (III)‐Komplexen als Vitamin‐B12‐Modellverbindungen
Authors: Rytz Gerhard , Scheffold Rolf
Published: December 2004

Synthesis of Octahydro‐porphinato‐cobalt(III) Complexes as Vitamin B12 Model Compounds

The synthesis of (±)‐dibromo[1‐hydroxy‐2,2,3,3,7,7,8,8,12,12,13,13,17,17,18,18‐hexadecamethyl‐10,20‐diaza‐octahydroporphinato]cobalt(III) (2a) is described. The dicyano complex 2b and the corresponding annulene complex 3 have been obtained by exchange of its axial ligands and by elimination of the hydroxy group, respectively.
Crystal Structure of 4‐Trimethyltin‐quinuclidinium Perchlorate
Authors: Zehnder Margareta
Published: December 2004

The crystal structure of 4‐trimethyltin‐quinuclidinium perchlorate has been determined by direct methods and refined by least squares techniques. Crystals of C10H22ClNO4Sn are monoclinic, space group I2/c with lattice parameters a = 29.445 (13), b = 18.400(8), c = 11.300(5) Å, β = 95.82(5)°, V = 6090.65Å3, and two independent molecules (Z = 16), Interatomic distances are compared with those of known structures of quinuclidinium chloride and 4‐haloquinuclidinium chlorides and perchlorates.
Alcaloïdes bis‐indoliques de Catharanthus ovalis
Authors: Langlois Nicole , Andriamialisoa Ratremaniaina Z. , Neuss Norbert
Published: December 2004

Bis‐indolic Alkaloids of Catharanthus ovalis

Vindolicine and fourteen bis‐indolic alkaloids of the vinblastine group have been isolated from the aerial parts of Catharanthus ovalis MGF. Three of them: vincovaline, vincovalinine and vincovalicine had not been previously isolated from a Catharanthus species.
1,2endo‐Trimethylenenorbornane. A novel isomer of adamantane
Authors: Jäggi Franz Josef , Ganter Camille
Published: December 2004

An easy approach to the novel adamantane isomer 1,2endo‐trimethylenenorbornane (2) is described. Starting from a mixture of pent‐4‐ynylcyclopentadienes 3 the tricyclic monosaturated key intermediate 5 was prepared by intramolecular cycloaddition (→4) and subsequent regioselective reduction of the C(5), C(6) double bond. The title hydrocarbon 2 was obtained from 5 upon stereoselective hydrogenation by diimide. In addition specifically deuteriated analogues of 2 were prepared applying dideuteriodiimide. Compound 2 rearranged to 2endo, 6endo‐trimethylenenorbornane (4‐homobrendane, 10) in sulfuric acid as well as with aluminium bromide in carbon disulfide.