bluuebunny/crossref_metadata_2025_split huggingface dataset:
Die Oxidation von 3‐(1‐Nitro‐2‐oxocycloalkyl)propanal
Authors: Zürcher Alois , Hesse Manfred 
Published: December 2004

The Oxidation of 3‐(1‐Nitro‐2‐oxocycloalkyl)propanalOxidation of the title compound 1 with KMnO4 under neutral conditions led to the corresponding acid 2, 5‐(2,3,4,5‐tetrahydro‐2‐nitro‐5‐oxo‐2‐furyl)pentanoic acid (4), and 4‐oxononadioic acid (6). On the basis of experimental results the mechanism of the formation of 4 is discussed (Scheme 1). Oxidation of 1 with KMnO4 under basic conditions gave 6 which was transformed to (E)‐4,5‐dihydro‐5(2′‐oxocyclopentyliden)furan‐2(3H)‐one (12) with benzene/TsOH (Scheme 3). In contrast to this result the corresponding 4‐oxoheptandioic acid (22) yields 1,6‐dioxaspiro[4,4]nonan‐2,7‐dione (23) only (Scheme 4).
Are the known Δ2‐cephems inactive as antibiotics because of an unfavourable steric orientation of their 4α‐carboxylic group? Synthesis and biology of two Δ2‐cephem‐4β‐carboxylic acids
Authors: Cohen Nissim C. , Ernest Ivan , Scartazzini Riccardo , Wirz Peter , Fritz Hans , Fuhrer Hermann , Rihs Grety 
Published: December 2004

AbstractTwo representatives of the yet unknown type of Δ2‐cephem‐4β‐carboxylic acids were prepared. Contrarily to the prediction based on the activity model of Cohen, both acids proved inactive as antibiotics. Possible reasons for this discrepancy are briefly discussed.
Preparation and Odor Evaluation of Both Enantiomers of 3,4,4aα,5,6,7,8,8aβ‐Octahydro‐5,5,8aβ‐trimethyl‐2(1H)‐naphthalenone and 1,2α,3,4,4aβ,5,6,7,8,8aβ‐Decahydro‐5,5,8aβ‐trimethyl‐2β‐naphthalenyl Acetate, Four Woody Odorants
Authors: Gautier Antoine , Vial Christian , Morel Cédric , Lander Marina , Näf Ferdinand 
Published: December 2004

AbstractThe enantiomeric decahydro‐2‐naphthalenols (+)‐5 and (−)‐5 were prepared by enantioselective hydrolysis of the racemic chloroacetate (±)‐2 catalyzed by porcine pancreatic lipase, and converted to the corresponding acetates (+)‐1 and (−)‐1 and ketones (+)‐6 and (−)‐6. The absolute configurations of the ketones, alcohols, and acetates were established by chemical correlation with natural manool ((+)‐7) by making use of a retro‐ene cleavage reaction of the known manool degradation product 8 to (−)‐6. A distinct odour difference between the two enantiomers of each pair (+)‐1/(−)‐1 and (+)‐6/(−)‐6 has been found.
Syntheses of bile pigments. Part 15. First unequivocal assignment of the absolute configuration of an urobilinoid bile pigment by X‐ray diffraction analysis of its synthetic precursor
Authors: Pasquier Cécile , Gossauer Albert , Keller Walter , Kratky Christoph 
Published: December 2004

Abstract(−)‐(4S,16S)‐8, 12‐bis[de(2‐carboxyethyl)]mesourobilin‐IIIα hydrochloride (8) has been synthesized from the enantiomerically pure 1,4,5,10‐tetrahydro‐1‐oxodipyrrin‐9‐carboxylic‐acid precursor 6a whose absolute configuration was determined by X‐ray diffraction analysis of the N‐[(S)‐1‐(1‐naphthyl)ethyl] carboxamide 7b. The present results prove unequivocally that an (S,S)‐configurated urobilin chromophore displays a negative Cotton effect in the VIS absorption range. However, the helicity of the inherently dissymmetric chromophore remains undetermined.
Enantioselektive Verseifung der Diacetate von 2‐Nitro‐1,3‐diolen mit Schweineleber‐Esterase und Herstellung enantiomerenreiner Derivate von 2‐Nitro‐allylalkoholen (chirale Verknüpfungsreagenzien)
Authors: Eberle Martin , Egli Martin , Seebach Dieter 
Published: December 2004

Enantioselective Saponification of Diacetates of 2‐Nitro‐1,3‐propanediols by Pig‐Liver Esterase and Preparation of Enantiomerically Pure Derivatives of 2‐Nitro‐allylic Alcohols (Chiral Multiple‐Coupling Reagents)The reproducible enantioselective saponification of open‐chain and cyclic diacetates of meso‐2‐nitro‐1,3‐propanediols (see 4b–13b) with pig‐liver esterase (PLE) gives monoacetates (see 4c–l3c) of > 95% enantiomeric excess. The Re enantiotopic acetate group appears to be saponified preferentially, as proved by the X‐ray crystal structure analysis of three camphanoates 4d, 6d, and 7d. Elimination of H2O or AcOH from the hydroxy acetates thus available gives derivatives of nitro‐allylic alcohols (see 20–24, 27, and 29) which are subjected to diastereoselective Michael additions or SN2′ substitutions.
Das Spermin‐Alkaloid Chaenorpin
Authors: Zhu Ji‐Ping , Guggisberg Armin , Hesse Manfred 
Published: December 2004

The Spermine Alkaloid ChaenorpineChaenorpine (1) was isolated from Chaenorhinum minus (Scrophulariaceae). Its structure elucidation was achieved on the basis of chemical degradation and spectroscopic measurements in comparison to the known alkaloid chaenorhine (2). Structure 1 displays the absolute configuration.
Nouveaux flavonosides de Paeonia tenuifolia L
Authors: Stošić Dus̀ica , Gorunović Momčilo , Skaltsounis Alexios‐Léandros , Tillequin François , Koch Miechel 
Published: December 2004

New Flavonoid Glycosides from Paeonia tenuifolia L.Two novel flavonoid glycosides have been isolated from the stamens of Paeonia tenuifolia, sexangularetin‐3‐O‐yl β‐D‐sophoroside (1) and limocitrin‐3‐O‐yl β‐D‐sophoroside (3). Their structures have been elucidated by spectroscopic means, mainly desorption chemical ionisation mass spectrometry and ID and 2D high‐resolution 1H‐NMR spectroscopy of their acety1 derivatives.
Synthesis of D‐Erythro‐ and D‐Threo‐Sphingosine Derivatives From L‐Serine
Authors: Herold Peter 
Published: December 2004

AbstractThe protected serine aldehyde 10 was converted to the crystalline N‐Boc‐protected sphingosines 6–9 by a three‐step reaction sequence. Compound 10 was transformed with high diastereoselectivity (95%) either to the erythro‐ or threo‐alkynols, 17 and 18, respectively. The erythro‐isomer 17 is formed by the addition to 10 of lithium pentadecyne 16 in THF/HMPT at −78°, whereas the corresponding threo‐isomer 18 is produced in the presence of ZnBr2 in Et2O. Deprotection of the acetal moiety afforded 1,3‐diols 19 and 20. These diols were selectively reduced with Red‐Al to the (E)‐sphingosines 6 and 8, or the (Z)‐isomers 7 and 9 by partial hydrogenation over Lindlar's catalyst. Cleavage of the N‐Boc group and further transformation to ceramides were readily achieved as demonstarted by the conversion of 6 to N‐octadecanoyl‐D‐erythro‐sphingosine 5.
Circular Dichroism of Planar, Exocyclic S‐cis‐Butadienes Remotely Perturbed
Authors: Zhichen Zou , Schwager Luis , Carrupt Pierre‐Alain , Vogel Pierre 
Published: December 2004

AbstractOptically pure 5,6‐dimethylidenebicyclo[2.2.1]hept‐2‐yl derivatives have been prepared. The sign of the Cotton effects associated with lowest‐energy transition of 2–(dicyanomethylidene)‐((−)‐(1S,4S)‐15), (E)‐2‐(methoxyimino)‐((+)‐(1S,4S)‐16), (Z)‐2‐(methoxyimino)‐5,6‐dimethylidenebicyclo[2.2.1]heptane ((−)(1S,4S)‐17), and 2,3,5‐trimethylidenebicyclo[2.2.1]heptane ((−)‐(1R,4S)‐18) is opposite to the chirality constituted by the coupling of the electric transition moments of the two homoconjugated π‐chromophores (Kuhn‐Kirkwood dipole‐coupling mechanism). When the substituents at C(2) are not π‐functions, no general rule can be retained for the chiroptical properties of the 5,6‐dimethylidenebicyclo[2.2.1]hept‐2‐yl systems as shown for dimethyl acetal (−)‐(1S,4S)‐19, ethylene acetal (+)‐(1R,4R)‐20, exo and endo methyl ethers (+)‐(1R,2S,4R)‐21 and (+)‐(1R,2R,4R)‐22, and for spirol[5,6‐dimethylidenebicyclo[2.2.1]heptane‐2.2'‐oxiranes](−)‐(1S,2S,4S)‐23 and (−)‐(1S,2S,4S)‐24.
New Reactions of 3‐Vinyl‐ and 3‐(2‐Propenyl)Indoles with N‐Phenylmaleimide: [4 + 2] Cycloaddition, ene reaction, and dimerization
Authors: Pfeuffer Ludwig , Pindur Ulf 
Published: December 2004

AbstractDepending on the substitution pattern of the aminobutadiene subunit in the selected 3‐vinylindoles 1, 3, 6, and 9, stereospecific [4 + 2] cycloadditions (‘endo’‐preference) and dimerizations take place on reaction with N‐phenylmaleimide. In the reaction of 9 with N‐phenylmaleimide in the absence of a Lewis‐acid catalyst, a competing ene reaction occurs in addition to the Diels‐Alder reaction.
First Total Synthesis of Enantiomerically Pure(−)‐Silphiperfol‐6‐en‐5‐on
Authors: Demuth Martin , Hinsken Werner 
Published: December 2004

AbstractThe angular triquinane (−)‐silphiperfol‐6‐en‐5‐on ((−)‐14) has been synthesized for the first time time in enantiomerically pure form. A highly efficient triplet‐sensitized photoreaction, the oxadi‐π‐methane rearrangement of the complex β,γ‐enone(+)‐6 to (−)‐7, constitutes the key step. The know staring material, (1R, 7aR)‐3,6,7,7a‐tetrahydro‐1‐hydroxy‐7a‐methyl‐1H‐inden‐5(2H)‐one ((−)‐2), is readily accessible in > 97% enantiomeric purity. This new approach should enable access also to other angularly fused triquinanes of the silphinene type and related structures.
Synthesis of selectively trifluoromethylated pyridine derivaties as potential antihypertensives
Authors: Lang Robert W. , Wenk Paul F. 
Published: December 2004

AbstractA general synthesis of selectively 6‐(trifluoromethyl)‐substitued 2(1H)‐pyridinones is described. Further transformation of one of these compounds leads to the new CF3‐containing potassium‐channel openers 2a and 2b.
A Stereoselective Synthesis of (±)‐cis‐γ‐Irone
Authors: Nussbaumer Cornelius , Fráter Georg 
Published: December 2004

Abstract(±)‐cis‐γ‐Irone(1), a main constitutent of natural iris oil, has been stereoselectively synthesized from methyl (2E)‐3 ‐[(2,2,4‐trimethyl‐3‐cyclohexen‐1‐yl)methoxy]‐2‐propenoate (3) (6 steps, overall yield 14%). The cis‐configuration as the exocyclic position of the double bond of 1 were secured by the thermal ene reaction of the β‐(alkenyloxy)acrylate 3 yielding the 3‐oxabicyclo [3,3,1] nonane derivative 5.
Enantiomerically pure 7‐oxabicylo[2.2.1]hept‐5‐en‐zyl derivatives as synthetic intermediates. Part III. Total synthesis of D‐ and L‐ribose derivatives
Authors: Wagner Jürgen , Vieira Eric , Vogel Pierre 
Published: December 2004

AbstractEnantiomerically pure methyl 5‐bromo‐5‐deoxy‐2,3‐O‐ isopropylidene‐β‐D‐ (D‐5b) and ‐β‐l‐ribofuranoside (l‐5b) have been derived from (−)‐(1R,2S,4R)‐2‐exo‐cyano‐7‐oxabicylo[2.2.1]hept‐5‐en‐endo,‐yl (1′S)‐camphanate (1) and (+)‐(1S,2R,4S)‐2‐exo‐cyano‐7‐oxabicyclo[2.2.1]hept‐5‐en‐2‐endo‐yl(1′R)‐camphanate (2), respectively, in 5 synthetic steps and 28% overall yield. Hydrolysis of D‐5b and L‐5b afforded methyl 2,3‐O isopropylidene‐β‐D‐ribofuranoside (D‐5a) and methyl 2,3‐O‐isopropylidene β‐L‐ribofuranoside (L‐5a), respectively. The intermediate (+)‐(1R,4R,5R,6R) 5‐exo,6‐exo‐(isopropylidenedioxy)‐7‐oxabicyclo[2.2.1]heptan‐2‐one ((+)‐7) and its enantiomer(–)‐7 were also obtained enantiomerically pure by resolution of (=)‐7 by the Johnson‐Zeller method. In bothe approaches, the chiral auxiliaries ((–)‐ and (+)‐camphanic acids, or (+)‐(S)‐N,S‐dimethyl‐S‐phenylsulfoximide) were recovered at an early stage of the synthesis.
(−)‐N‐[(Cyclopropyl) methyl]‐3,4‐dimethoxy‐5‐methylmorphinan‐6‐one, an opioid agonist with preference for kappa opioid receptors
Authors: Schmidhammer Helmut , Fritsch Florian , Burkard Willy P. , Eggstein‐Aeppli Lislott , Hefti Fridolin , Holck Mark I. 
Published: December 2004

AbstractN‐Allyl‐ and N‐[(Cyclopropyl)methyl]‐3,4‐dimethoxy‐5‐methylmorphinan‐6‐one (9 and 10, resp.) were synthesized from 5‐methyldih drothebainone (1). This essential intermediate was prepared from the baine via 5‐methylthebaine (5) employing a novel route. The Pharmacological studies showed 9 and 10 to be potent opioid agonists. Compound 10 was found to have preference for kappa rather than mu opioid receptors.
Transition‐metal complexes with bidentate ligands spanning trans‐position. Part XVI. X‐ray structural and 31P‐NMR solution studies of 2,11‐Bis(diethylphosphinomethyl)benzo[c]phenanthrenesilver(I) perchlorate
Authors: Camalli Mercedes , Caruso Francesco , Chaloupka Stanislav , Chaloupka Luigi , Venanzi Luigi M. 
Published: December 2004

AbstractThe preparation of complexes {AgX(1c)} (X  Cl, Br, I, NO3 and ClO4; 1c = 2,11‐bis(diethylphosphinomethyl)benzo[c]phenanthrene) is reported. The 31P‐NMR spectra of the above complexes were recorded and the 1J(107Ag, 31P) values are compared with the corresponding data for related complexes. The X‐ray crystal structure of [Ag(1c)](ClO4) was determined. There are two crystallographically independent molecules in the unit cell each containing two‐coordinate silver, the O‐atoms of the perchlorate anions being outside bonding range from the central atom. The two molecules, however, show different bonding parameters: Thus for ‘molecule 1’ P(1)Ag(1)P(2) = 167.6(1)°, Ag(1)P(1) = 2.389(3) and Ag(1)P(2) = 2.393(3) Å, while for ‘molecule 2’ P(3)Ag(2)P(4) = 164.8(1)°, Ag(2)P(3) = 2.377(3), and Ag(2)P(4) = 2.378(3) Å. These differences are probably due to packing forces in the crystal lattice.
A (1,5)‐Vinyl Shift
Authors: Fráter Georg , Müller Urs 
Published: December 2004

AbstractThe structure of the by‐product of the pyrolysis of 1 has been proved to be 3. It is proposed that a (1, 5) Shift of an (alkoxycarbonyl)vinyl group (8⇄10) is the step in formation of 3.
Metabolism of Carotenoids in Salmonids. Part 3. Metabolites of astaxanthin and canthaxanthin in the skin of atlantic salmon (salmo salar, L.)
Authors: Schiedt Katharina , Vecchi Max , Glinz Ernst , Storebakken Trond 
Published: December 2004

AbstractDiets supplemented with astaxanthin and canthaxanthin, respectively, and a control diet without carotenoid additions, were fed to 1½‐year‐old Atlantic salmon (Salmo salar, L.) for one year. The integuments were investigated as to their quantitative and qualitative carotenoid composition. Astaxanthin and canthaxanthin deposited in the skin amounted to 20 and 14% of the total carotenoids only. Seventy % must be considered as metabolites of astaxanthin and canthaxanthin and 10% as basic xanthophylls also present in the control groups. Astaxanthin apparently underwent the following metabolic pathway: astaxanthin→idoxanthin→adonixanthin→zeaxanthin→zeaxanthin 5,6‐epoxides. Reduction of the 4′‐carbonyl group was stereospecific leading to the (4′R)‐idoxanthin. Canthaxanthin was obviously converted to β,β‐carotene via 4′‐hydroxyechinenone, echinenone, and 4‐hydroxy‐β,β‐carotene.
EPC syntheses from bicyclic dixoanones; (−)‐5‐epidehydrofukinone
Authors: Herradón Bernardo 
Published: December 2004

Abstract(−)‐5‐Epidehydrofukinone ((−)‐15) has been synthesized from (2S,4aS,5S,8aS)‐4a,5‐dimethyl‐2‐(tert‐butyl)‐perhydro‐4H‐1,3‐benzodioxan‐4‐one (4a), a counpound readily available by yeast reduction of ethyl 2‐oxocyclohexanecarboxylate.
Thermal and Photochemical Oxetane Formation. A Contribution to the Synthesis of Branched‐Chain Aldonolactone
Authors: Mattay Jochen , Buchkremer Karl 
Published: December 2004

AbstractDerivatives of 2‐C‐branched‐chain erythrono‐1,4‐lactones of the types 1 have been synthesized under reductive conditions using DIBAL from the oxetane 2, which is easily accessible from diethyl mesoxalate (4) and 2,2‐diisopropyl‐1,3‐dioxole (3) in high yield by means of a catalytic cycloaddition. Similarly, 2 rearranges in presences of AlMe3 under formation of an erythronolactone with an additional branching at C(4). The corresponding oxetanes 7–9 from ethyl pyruvate (5) and ethyl trimethylpyruvate (6), respectively, have been studied with regard to their reductions yielding building blocks of branched‐chain sugars.
A Vibrational Study of Some 1,2,4‐Trioxanes
Authors: Mohnhaupt Martin , Hagemann Hans , Perler Jean‐Pascal , Bill Hans , Boukouvalas John , Rossier Jean‐Claude , Jefford Charles W. 
Published: December 2004

AbstractThe vibrational spectra of some 1,2,4‐trioxanes present two characteristic bands at 790 and 880 cm−1. On the basis of 18O‐isotopic substitution and comparison with analogous compounds, these bands have been assigned to coupled CO and OO stretching modes of the COO element.
Singlet‐Oxygen Quenching by Carotenoids: Steady‐state luminescence experiments
Authors: Murasecco‐Suardi Patricia , Oliveros Esther , Braun André M. , Hansen Hans‐Jürgen 
Published: December 2004

AbstractThe near‐infrared luminescence of singlet oxygen (1O2) has been measured in order to determine the efficiency of 1O2 quenching by two carotenoid compounds, β‐carotene and canthaxanthin. 1H‐Phenalen‐1‐one and rose bengal have been used as photosensitizers in those steady‐state luminescence experiments. Stern‐Volmer analysis of the 1O2 luminescence in solutions of CCl4 and CD3OD, containing different concentrations of the carotenoids, has shown a very efficient quenching by canthaxanthin. The rate constants are about a factor of 2 below the diffusion limited values for the given solvents, confirming earlier results in benzene. In comparison, the efficiency of 1O2 quenching by β‐carotene is slightly lower than that by canthaxanthin in non‐polar solvents and is reduced by an order of magnitude in CD3OD, due to the aggregation of this quencher.
Synthesis and Characterisation of the Sodium and Lithium Cryptates of Macrobicyclic Ligands incorporating pyridine, bipyridine, and biisoquinoline units
Authors: Alpha Béatrice , Anklam Elke , Deschenaux Robert , Lehn Jean‐Marie , Pietraskiewiez Marek 
Published: December 2004

AbstractSythetic procedures have been deweloped for the preparation of sodium and lithium cryptates of the macrabicyclic ligands 1–11 containing pyridine, bipyridine, and biisoquinoline groups. They involve stepwise construction of the bicyclic system as will as direct macrobicyclisation procedures (Scheme 1) and give access to both symmetrical and dissymmetrical structures. Marked cation template effects have been found that facilitate the cyclisation processes. The ligands 1–11 were isolated as their cryptates with Na+ or Li+ cations.
Absorption Spectra and Luminescence Properties of Isomeric Platinum (II) and Palladium (II) Complexes containing 1,1′‐biphenyldiyl, 2‐phenylpyridine, and 2,2′‐bijpyridine as ligands
Authors: Maestri Mauro , Sandrini Diana , Balzani Vincenzo , von Zelewsky Alex , Deuschel‐Cornioley Christine , Jolliet Philippe 
Published: December 2004

AbstractThe absorption spectra, luminescence spectra, and luminescence lifetimes of the isomeric [M(bph)(bpy)] and [M(phpy)2] complexes M = Pt(II) or Pd(II), bph2− = 1,1′‐biphenyl‐2,2′‐diyl dianion, phpy− = 2‐phenylpyridine‐2′‐yl anion, and bpy = 2,2′‐bipyridine have been investigated and compared with those of [M(bpy)2]2+ complexes and of the free protonated ligands H2bph, Hbpy+, and Hphpy. In the absorption spectra, the region below 320 mm is dominated by ligand‐centered (LC) transitions, whereas metal‐to‐ligand charge transfer (MLCT) transitions are responsible for the bands present in the near UV/VIS region. The MLCT bands move to higher energies on replacing Pt with Pd and in going from [M(bph)(bpy)] to the [M(phpy)2] isomer. For the mixed‐ligand complexes, evidence for both M → bph2− (at higher energies) and M → bpy bands is found. The structured luminescence observed at 77 K shows lifetimes of 4.0 and 1.1 μs for [Pt(phpy)2] and [Pt(bph)(bpy)], respectively, and 480 and 250 μs for the analogous Pd complexes. On the basis of the energy and lifetime data, the luminescence of the Pt(II) complexes is assigned to the lowest triplet MLCT excited state, whereas for the Pd complexes the luminescent state is thought to result from a mixture of MLCT and LC triplet levels.
First Synthesis of 2‐Vinylindole and its diels‐Alder Reactions with CC‐Dienophiles
Authors: Pindur Ulf , Eitel Manfred 
Published: December 2004

AbstractBy means of an intramolecular Wittig process, 2‐vinylindole (2) was prepared. The indole 2 functions as a heterocyclic, donor‐activated 1,3‐diene and undergoes [4+2] cycloaddition reactions with dimethyl acetylenedicarboxylate, N‐phenylmaleimide, and p‐benzoquinone leading to the novel carbazole dervatives 3, 4, 5c, 6 and 7 respectively. The reaction of 2 with acceptor (A)‐Substituted dienophiles (e.g.) ACHCH2, AC≡(CH) does not yield products that can be isolated.
Design and Synthesis of 5‐Lipoxygenase Inhibitors
Authors: Strasser Michael , Cooper Philip , Dewald Beatrice , Payne Trevor 
Published: December 2004

AbstractBased on the substrate specificity for 5‐lipoxygenase and the known stereochemical course of the reaction, a hypothetical model of the enzyme active site was developed and used to design 2 types of selective inhibitors of 5‐lipoxygenase. Both inhibitor types used aromatic rings in place of (Z)‐olefins of the substrate and were designed to mimic the nonpolar end of arachidonic acid. One inhibitor type used a carboxylic‐acid interaction with the O‐binding centre of the enzyme in analogy with known cyclooxygenase inhibitors, whereas a second type employed a hydroxylamine function to interact with a presumed tyrosine or cysteinyl radical predicted to be in the enzyme active site. Selective 5‐lipoxygenase inhibitors were 7‐(hexyloxy) naphthalene‐2‐acetic acid (1) and N‐methyl;‐N(7‐propoxynaphthalene‐2‐ethyl)hydroxylamine (2). Structure‐activity relationships for both types of inhibitors are discussed.
Colchicine Models: Synthesis and Binding to Tubulin of Tertamethoxybiphenyls
Authors: Itoh Yoshikuni , Brossi Arnold , Hamel Ernest , Lin Chii M. 
Published: December 2004

AbstractSyntheis of tetramethoxybiphenyl 21 was accomplished from 4‐phenylcylohexane‐1,3‐dione 13 by aromatization to biphenyl 19 and reductive removal of the phenolic OH group as phenyltetrazolyl ether. Tertramethoxybiphenyls 34 and 40 were obtained from 4‐phenylcyclohexenone 26 via ester 27. The tetramethoxybiphenyls 21, 34, and 40, and analogs 28, 29, and 31 were evaluated for antitubulin activity and as antimitotic agents with L1210 murine leukemia cells. Compounds 31 and 34 had significant effects on the in‐vitro polymerization of tubulin. Compound 31 was the most cytotoxic of the six new biphenyls studied (IC50 for cell growth, 0.6M) and caused the accumulation of cells in metaphase arrest.
Antifungal Polyphenols from Cordia goetzeiGürke
Authors: Marston Andrew , Zagorski Michael G. , Hostettmann Kurt 
Published: December 2004

AbstractFour highly oxygenated polyphenols 1–4, have been isolated from the stem bark of Cordia goetzei Gürke (Boraginaceae) and their structures elucidated by a combination of one‐ and two‐dimensional (including COLOC) NMR spectroscopic techniques, mass spectroscopy, and chemical methods. The first new compound, cordigone (1), is a tetrahydrofuran derivative and the second one, cordigol (2), a furobenzopyran derivative. The benzofurans 3 and 4 are orange pigments, responsible for the coloration of the stem bark of the tree. All four polyphenols are fungicidal against cladosporium cucumerinum.
Synthese neuer schwefel‐ und selen‐haltiger ‘Donor‐Akzeptor‐stabilisierter’ Molekülsysteme mit zentraler bicyclo[4.4.1]undeca‐4,6,8,10‐tetraen‐2,3‐diyliden‐ oder Bicyclo[4.4.1]undeca‐3,6,8,10‐tetraen‐2,5‐diyliden‐Gruppe
Authors: Neidlein Richard , Lucchesini Francesco 
Published: December 2004

Synthesis of New Sulfur‐ and Selenium‐Containing ‘Donor‐Acceptor‐Stabilized’ Systems with Central Bicyclo‐[4.4.1]undeca‐4,6,8,10‐tetraene‐2,3‐diylidene‐ or Bicyclo[4.4.1]undeca‐3,6,8,10‐tetraene‐2,5‐diylidene GroupsSyntheses of starting materials 3–55 and 8 and of the S‐ and containing 1,6‐methano[10]annulene (=1,6‐methanobicyclo[4.4.1]undeca‐1,3,5,7,9‐pentaene) derivatives 12, 13, 15 and 16 are described.
Conformational Flexibility of the Acetoxyphenyl Group Studied by Statistical Analysis of Crystal Structure Data
Authors: Hummel Wolfgang , Roszak Aleksander , Bürgi Hans‐Beat 
Published: December 2004

AbstractThe preferred conformation of the acetoxyphenyl fragment shows a planar acctoxy (AcO) group perpendicular to the Ph ring. Steric hindrance strongly limits and affects rotation about the COCOCH3 bond: if the AcO group twists away from its perpendicular conformation, the carbonyl oxygen moves to keep the nonbonded distance to the atoms in ortho‐position maximal. This is achieved by some twisting about the OCOCH3 bond correlated with angle bending at the ipso‐C‐atom and ester O‐atom. The maximum observed deviation away from the perpendicular conformation is ∼ 47°. In the case of one or two ortho‐hydrogens, deviations of the AcO group from the perpendicular conformation tend to be larger than in the case of two substituents.