bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of Alkenyl‐Substituted Allenecarboxylates
Authors: Lang Robert Werner , Kohl‐Mines Elisabeth , Hansen Hans‐Jürgen 
Published: December 2004

AbstractThe Wittig olefination of decanoyl chloride by using the phosphonium salt 1 in the presence of two equivalents of Et3N represents a one‐step synthesis of the racemic form of the naturally occurring pheromone (–)‐2 which contains an alkenyl‐substituted allenic moiety (ef. Scheme 1). It is also shown, that unsaturated acyl chlorides which contain at least one γ‐H‐atom undergo the Wittig reaction with an appropriate phosphorane yielding γ‐alkenyl‐substituted α‐allenic esters and α‐allenic γ‐lactones, respectively (ef. Schemes 2 and 3).
Zur Kenntnis des Faktors F430 aus methanogenen Bakterien: Absolute Konfiguration
Authors: Fässler Alexander , Kobelt André , Pfaltz Andreas , Eschenmoser Albert , Bladon Christine , Battersby Alan R. , Thauer R. K. 
Published: December 2004

Factor F430 from Methanogenic Bacteria: Absolute ConfigurationExperiments on F430M (2) aiming at a potentially biomimetic, reductive reconstruction of the F430 (1) chromophore from corresponding pyrrocorphinate intermediates provided us with F430 derivatives which contain an isobacteriochlorinate chromophore system similar to the one occurring in sirohydrochlorin (3) (cf. the Scheme). Comparison of their CD spectra with the‐CD spectrum of nickel(II)‐sirohydrochlorinate octamethyl ester demonstrates that the absolute configurations of factor F430 and sirohydrochlorin in the region of rings A and B are the same.
Chemical Alterations in Native Histone Octamer Complexes Induced by the Attak of · OH and · N3 Radicals
Authors: Deeg Klaus‐Jürgen , Katsikas Lynne , Schnabel Wolfrman 
Published: December 2004

Abstract·OH Radicals generated by short electron‐beam pulses were allowed to attack histone octamer complexes (extracted from calf‐thymus chromatin) in N2O‐saturated dilute solution (0.5–1.3 g/l, [NaClO4] = 1 – 2M, pH 9). They induced a volume contraction due to intra‐complex cross‐linking. In this process, essentially non‐tyrosine moieties of the proteins were involved. Phenol coupling via tyrosyl radicals occurred mainly as an intramolecular reaction, i.e., it was restricted to single histone moelecules. Furthermore, it turned out that only about 55% of the tyrosine moieties were accessible to attacking ·OH and/or ·N3 radicals. When ·N3 radicals were generated via continuous irradiation of N2O‐saturated octamer solutions containing NaN3 with 60Co‐γ‐rays, dimers, trimers, and tetramers were detected by SDS gel electrophoresis, in contrast to pulse radiolysis where only dimers were found. These results were explained in terms of denaturation being induced by small chemical changes and causing partial or complete dissociation of the complexes thus permitting, in the course of the γ‐irradiation, the attack and conversion of amino‐acid moieties non‐accessible in the native octamer complexes. Removal of steric restrictions for the combination of tyrosyl radicals may also play a role. By time‐resolved absorption measurements, it was shown that, upon the attack of intact octamer complexes by ·OH radicals, tyrosyl radicals were formed which were converted to dityrosine groups according to two modes with half‐lives of several 100 m̈s and 1–2 ms, respectively. Cross‐linking of histone molecules occurred with a definitely lower rate (1st half‐life: 50 100 ms). This process was detectable both by optical absorption measurements at λ = 300 400 nm and by light‐scattering measurements.
Interactions between Functional Groups. Part III. The Structure of N,N‐Dimethyl‐8‐nitro‐1‐naphthaleneamine in Seven Crystalline Environments
Authors: Egli Martin , Wallis John D. , Dunitz Jack D. 
Published: December 2004

AbstractThe N,N‐dimethyl‐8‐nitro‐1‐naphthaleneamine molecule has been observed in seven environments in three crystal modifications. A range of conformations, related by conrotatory motions about the two exocyclic CN bonds, is observed. In all seven conformations, the lone pair of the amino N‐atom is directed approximately towards the nitro N‐atom, which is slightly pyramidalized towards the amino group. The NO2 group appears to be a poorer through‐space electron acceptor than the carboxylic ester group, in contrast to their through‐bond electron‐accepting properties.
Structural and Spectroscopic Investigations of the 1:1 Complex between Europium Nitrate and a Tetraoxadiaza Macrocycle
Authors: Bünzli Jean‐Claude G. , Leonard Gordon A. , Plancherel Dominique , Chapuis Gervais 
Published: December 2004

AbstractThe crystal and molecular structure of dinitrato(1,7,10,16‐tetraoxa‐4,13‐diazacyclooctadecane)europium(III) nitrate, ([Eu(NO3)2(C12H26N2O4)]NO3) has been determined from single‐crystal X‐ ray diffraction: a = 12.567(3), b = 11.585(3), c = 16.354(5) Å, β = 112.45(2)°, space group P21/n, Z = 4. The structure consists of discrete dinitrato complex cations and of nitrate anions. The Eu(III) ion is 10‐coordinate, bonding to the six donor atoms of the macrocycle and to four O‐atoms of the two bidentate nitrates. The mean distances are EuO(ether) = 2.60(2), EuO(NO3) = 2.47(3) and EuN = 2.62(2) Å. The metal site has an approximate C2 symmetry. The IR and Raman spectra show the presence of an ionic and of two bonded bidentate nitrates. These latter have a different v1‐v4 splitting, which reflects their dissymmetrical bonding. Luminescence spectra have been recorded at 296, 77, and 4 K by laser‐excitation techniques. One sharp 5D0←7F0 transition was observed and almost all the sublevels of the 7FJ manifold could be identified. The interaction between a sharp distribution of the phonon states (especially between 950 and 1200 cm−1) and the electronic 7F2 sublevels results in the presence of several satellite lines accompanying the 5D0→7F2 transition. In MeCN solutions, both luminescence and conductivity data point to the presence of the [Eu(NO3)2(2,2)]+ cation.
Reaktionen von 3‐substituiertem 5‐Trifluormethyl‐1,3,4‐oxadiazol‐2(3H)‐on mit Nucleophilen
Authors: Kristinsson Haukur , Winkler Tammo , Mollenkopf Max 
Published: December 2004

Reactions of 3‐Substituted 5‐Trifluoromethyl‐1,3,4‐oxadiazol‐2(3H)‐one with NucleophilesThe 3‐substituted 5‐trifluoromethyl‐1,3,4‐oxadiazolones 3, 4, 13, and 15 are attacked by N‐ and S‐nucleophiles either at the ring C‐atom C(2) or C(5). Depending on the nature of the substituent and the nucleophile, the ring‐opening products 7, 10, 12, and 14 or the ring‐enlargement products 16 are formed. The reaction of 4 with thiols is a novel variant of the Grob‐type fragmentation. The reactivity of the 1,3,4‐oxadiazolones is compared with that of the analogous 1,3,4‐thiadiazolones. The structures of the new compounds were elucidated by 1H‐ and 13C‐NMR spectroscopy.
Optisch aktive 4,5‐Epoxy‐4,5‐dihydro‐α‐ionone und Synthese der stereoisomeren 4,5:4′,5′‐Diepoxy‐4,5,4′,5′‐tetrahydro‐ϵ,ϵ‐carotine und der sterische Verlauf ihrer Hydrolyse
Authors: Uebelhart Peter , Baumeler Andreas , Haag Andreas , Prewo Roland , Bieri Jost Hans , Eugster Conrad Hans 
Published: December 2004

Optically Active 4,5‐Epoxy‐4,5‐dihydro‐α‐ionones; Synthesis of the Stereoisomeric 4,5:4′,5′‐Diepoxy‐4,5,4′,5′‐tetrahydro‐ϵ,ϵ‐carotenes and the Steric Course of their HydrolysisWe prove that epoxidation with peracid of α‐ionone, contrary to a recently published statement, predominantly leads to the cis‐epoxide. Acid hydrolysis affords a single 4,5‐glycol whose structure, established by an X‐ray analysis, shows that oxirane opening occurred with inversion at the least substituted position (C(4)). Stable cis‐and trans‐epoxides are prepared by epoxidation of the C15‐phosphonates derived from α‐ionone. Both the racemic and optically active form are used for the synthesis of the 4,5:4′,5′‐diepoxy‐4,5,4′,5′‐tetrahydro‐ϵ,ϵ‐carotenes having the following configuration in the end groups: meso‐cis/cis, meso‐trans/trans, rac‐cis/trans, rac‐ and (6R, 6′ R)‐cis/cis, rac‐ and (6R, 6′R)‐trans/trans, rac‐ and (6R, 6′R)‐cis/trans, and (6R, 6′ R)‐cis/ϵ. Acid hydrolysis of the cis/cis‐epoxycarotenoids under relatively strong conditions occurs again with inversion at C(4)/C(4′) in case of the cis/cis‐epoxycarotenoids, but at C(5)/C(5′) in case of the trans/trans‐epoxycarotenoids. An independent synthesis of this 4,5,4′,5′‐tetrahydro‐ϵ,ϵ‐carotene‐4,5,4′,5′‐tetrol is presented. The irregular results of the oxirane hydrolysis are explained by assumption of neighbouring effects of the lateral chain. 400‐Mz‐1H‐NMR data are given for each of the stereoisomeric sets. In the visible range of the CD spectra, the (6R, 6R′)‐epoxycarotenoids compared with (6R, 6R′)‐ϵ,ϵ‐carotene exhibit an inversion of the Cotton effects.
An Ag‐Atom in the 6‐6 Subunit of a Zeolite: Model Calculations
Authors: Calzaferri Gion , Forss Lars 
Published: December 2004

AbstractSelf‐sensitisation of photo‐oxygen evolution occurs in aqueous dispersions of silver zeolites. In presence of Cl−, chlorine is the photoproduct in acidic medium, and the same type of self‐sensitisation occurs. Self‐sensitisation means that systems which are first insensitive to light of a certain wavelength become photo‐active after they have been illuminated by light of higher energy. For a better understanding of silver zeolites, we have carried out EH‐MO calculations on the 6–6 subunit (SBU) of a zeolite, on the 6–6 SBU with an Ag‐atom in the center, on the 6–6 SBU with one Ag‐atom in the center and one outside on top of the hexagon, and finally on another with one Ag‐atom in the center and two Ag‐atoms outside, each on top of a hexagon. The Ag0 in the cage of the 6–6 SBU is significantly polarized by the 6–6 SBU environment. The energy barrier to escape the 6–6 SBU is 0.8 eV for Ag0 and 0.5 eV for Ag+. The HOMO of the Ag(6–6 SBU) is a totally symmetric 5s* orbital and the LUMO is a 5pz* type. 5pz*←5s* electronic excitation reduces the energy barrier and allows an (Ag0)* to exit the 6–6 SBU, provided the excited‐state lifetime is long enough. The MO picture predicts low‐energy charge‐transfer transitions from the zeolite framework to the 5s* orbital. The highest occupied orbitals of the zeolite framework are localized on the O‐atoms. Interactions between an Ag‐atom in the 6–6 SBU and one or two external Ag‐atoms are discussed.
Fluorine‐Containing Organozinc Reagents Part 1 A Simple Synthesis of 2,2‐Dichloro‐3,3,3‐trifluoropropanol
Authors: Lang Robert Werner 
Published: December 2004

AbstractThe title compound 1, which can be regarded as a synthetic equivalent of substituted 1,1,1‐trifluoroacetone 2, is prepared by Zn‐induced reductive addition of 1,1,1‐trichloro‐2,2,2‐trifluoroethane (3) to formaldehyde (4). A brief survey of the scope of this CC‐bond formation leading to a variety of new CF3‐containing synthetic building blocks is also given.
5‐(N‐Arylnortropan‐3‐yl)‐ and 5‐(N‐Arylpiperidin‐4‐yl)‐2,4‐diaminopyrimidines. Novel Inhibitors of Dihydrofolate Reductase
Authors: Maag Hans , Locher Rita , Daly John J. , Kompis Ivan 
Published: December 2004

AbstractBased on a computer‐assisted analysis of the three‐dimensional structure of the binary complex of E.coli dihydrofolate reductase (DHFR) with methotrexate, 5‐(N‐arylnortropan‐3‐yl)‐ and 5‐(N‐arylpiperidin‐4‐yl)‐2,4‐diaminopyrimidines 2 and 4 were designed as inhibitors of DHFR. Syntheses of the designed compounds have been carried out. The most potent compound 2a inhibited E. coli DHFR with Ki = 0.49.10−9M. The activities within the series of compounds synthesized could be rationalized by molecular‐modelling experiments which served as the basis of this work. Several compounds within the presented series exhibit antimalarial activities in vitro and in vivo.
Nucleosides and nucleotides part 24 Investigation of ribo‐ and deoxyribonucleosides and ‐nucleotides by fast‐ atom‐bombardment mass spectrometry
Authors: Hogg Alan M. , Kelland Janice G. , Vederas John C. , Tamm Christoph 
Published: December 2004

AbstractThe fast‐atom‐bombardment mass spectra (FAB‐MS) of a series of ribo‐ and deoxyribonucleosides and ‐nucleotides were examined in both positive‐ion and negative‐ion modes. Behaviour of cytosine analogs having unnatural bases (2(1H)‐pyrimidone, 2(1H)‐pyridinone, and 4‐amino‐2(1H)‐pyridinone) was similar to that of compounds having naturally occurring bases. Nucleotides protected by dimethoxytrityl and p‐chlorophenyl groups were also investigated using this technique. Use of negative‐ion mode reduces interference from positive counter‐ions (e.g., Na+) and allows rapid sequence determination of simple di‐ and trinucleotides.
Synthese und Strukturaufklärung von Merucathin und Pseudomerucathin. Zwei Inhaltstoffe von Catha edulis FORSK
Authors: Wolf Jean‐Pierre , Pfander Hanspeter 
Published: December 2004

Synthesis and Structure Elucidation of Merucathine and Pseudomerucathine. Two Constituents of Catha edulis FORSK.Starting from L‐alanine, two constituents of Catha edulis FORSK. (3R,4S)‐4‐amino‐1‐phenyl‐1‐penten‐3‐ol ((3R,4S)‐4, merucathine) and (3S,4S)‐4‐amino‐1‐phenyl‐1‐penten‐3‐ol ((3S,4S)‐4, pseudomerucathine) were synthesized.
PE Spectra of Dewar Benzenes, Bridged by a Cyclohexadiene or a Butadiene Unit
Authors: Gleiter Rolf , Krennrich Gerhard , Bischof Peter , Tsuji Takashi , Nishida Shinya 
Published: December 2004

AbstractThe electronic structure of [4.2.2]propella‐2,4,7,9‐tetraene (1), 2,5‐etheno[4.2.2]propella‐3,7,9‐triene (2), and of several hydrogenated derivatives of 2 has been investigated using He(I) PE spectroscopy and MO calculations. It is found that in 2 the 1,4‐cyclohexadiene moiety interacts considerably with the bicyclo[2.2.0]hexadiene unit, while in 1 the interaction between the butadiene fragment and the Dewar benzene unit is minute. The syntheses of 3–5 are reported.
Neue Diterpene aus Blattdrüsen von Plectranthus barbatus (Labiatae). Die absolute Konfiguration der 2‐Hydroxypropyl‐Seitenkette in Coleon E
Authors: Rüedi Peter 
Published: December 2004

Novel Diterpenoids from Leaf Glands of Plectranthus barbatus (Labiatae). The Absolute Configuration of the 2‐Hydroxypropyl Group in Coleon EIn addition to the previously reported quinone methides coleon E (1a), coleon F (2a) and the spirocoleon 9 (plectrin), novel rearranged abietanoid dienediones, called (16R)‐plectrinon A (3a) and plectrinon B (5) as well as the allylroyleanone 8a have been isolated from Plectranthus barbatus and their structures elucidated mainly by spectroscopy. Closer investigation of acetylations of 1a and 2a established the hitherto unknown structures 1c, 2c, 3b, 10a, 10b, 11a, 11b, 12a, and 12b. The derivatives 3b, 11a, 11b, 12a, and 12a, and 12b are the products of a nucleophilic attack at the quinone methide system. The analysis of the 13C‐NMR spectra led to the full assignment of the signals in 1a, 1b, 2a, 3a, and 8a. Correlations by partial syntheses of 3a, from coleon E(1a), after oxidation or acetylation/saponification of the latter, established the (R)‐configuration of the 2‐hydroxypropyl group in 1a. The biomimetic transformation of plectrin (9) into (16R)‐coleon E (1a) is shown to proceed via the unexpected, highly reactive 2‐methylspiro[cyclopropane‐1,2′‐(2′H)‐phenanthrene]‐1′,3′, 6′‐trione 13. The solvolysis of the spiro(methylcyclopropane) moiety takes place with inversion of the configuration at the attacked C‐atom, as established in a previous communication. The 1,3,6‐trione 13 is supposed to be also the key intermediate in the biosynthesis of the allyl group in coleon F (2a) which proceeds via a homosigmatropic [1,5]‐H shift.
Photogeneration of Carbon Monoxide and of Hydrogen via Simultaneous Photochemical Reduction of Carbon Dioxide and Water by Visible‐Light Irradiation of Organic Solutions Containing Tris(2,2′‐bipyridine)ruthenium(II) and Cobalt(II) Species as Homogeneous Catalysts
Authors: Ziessel Raymond , Hawecker Jeannot , Lehn Jean‐Marie 
Published: December 2004

AbstractCO and H2 are photogenerated simultaneously by visible‐light irradiation of systems containing a photosensitizer, the [Ru(bpy)3]2+ complex, Co(II) species as homogeneous catalysts, which mediate CO2 and H2O reduction by intermediate formation of Co(I), a tertiary amine as electron donor, which provides the electrons for the reduction, and an organic solvent which also facilitates dissolution of CO2. The efficiency of (CO + H2) gas production and the selectivity CO/H2 markedly depend upon the composition of the medium, the nature of the tertiary amine, the solvent, and the ligand of the Co ions. 2,9‐Dimethyl‐1,10‐phenanthroline is particularly effective in promoting CO and H2 formation, giving a quantum yield of 7.7% in (CO + H2) (1.2% for CO and 6.5% for H2). The process consists of two catalytic cycles: a photocatalytic cycle for the Ru complex and a double dark reaction pathway for the Co species; oxidative and/or reductive quenching of the excited state of the photosensitizer lead to the formation of Co(I) species which reduce either CO2 or H2O to CO or H2, respectively.
Isoswerosid, ein neues Secoiridoidglycosid aus den Wurzeln des Zwergholunders Sambucus ebulus L. (Caprifoliaceae). 2. Mitteilung über die Inhaltsstoffe der Zwergholunderwurzel
Authors: Gross Gian‐Andrea , Sticher Otto 
Published: December 2004

Isosweroside, a New Secoiridoid Glycoside from the Roots of Sambucus ebulus L. (Caprifoliaceae)The paper describes the isolation and structure elucidation of isosweroside (6‐(β‐D‐ glucopyranosyloxy)‐methyl‐9‐vinyl‐2,8‐dioxabicyclo[3.3.1]non‐6‐en‐3‐one), the first Valeriana‐type secoiridoid glycoside from the roots of Sambucus ebulus L. along with the two known glycosides ebuloside and morroniside.
Diels‐Alder Approach to Highly Functionalized Tertiary α‐Hydroxy Ketones: A Novel Route to the Hexahydrobenzofuran Portion of the Avermectins and Milbemycins
Authors: Ireland Robert E. , Obrecht Daniel M. 
Published: December 2004

AbstractA highly regio‐ and stereoselective Diels‐Alder reaction between dienophiles of type I and dienes of type II (Scheme 1) gives rise to Diels‐Alder adducts of type III. Upon treatment with BF3.Et2O, these adducts are smoothly converted into the corresponding enones (Scheme 6). Under mild acidic conditions, enone (±)‐33 gave bicyclic diketone (±)‐34 via an intramolecular Michael‐type addition. Diketone (±)‐34 has the correct relative configuration and a suitable ketone function at C(6) for further conversion into the hexahydrobenzofuran portion of the avermectins and milbemycins.
Photochemical reactions. 148th communication. Photochemistry of acylsilanes: Preparation, photolyses, and thermolyses of α,β‐unsaturated silyl ketones
Authors: Scheller Markus E. , Iwasaki Genji , Frei Bruno 
Published: December 2004

AbstractThe syntheses, photolyses, and thermolyses of the α,β‐unsaturated silyl ketones (E/Z)‐7, (E)‐8, and (E)‐9 are described. On n,π*‐excitation (λ > 347 mm), the aforementioned compounds undergo (E/Z)‐isomerization followed by γ‐H abstraction. The intermediate enols are trapped intermolecularly by siloxycarbenes leading to the dimeric acetals 27A + B, 30A + B, and 31A + B. In addition, the acylsilanes (E/Z)‐7 undergo photoisomerization by δ‐H abstraction furnishing the acylsilanes 29A + B. Flash vacuum thermolyses (FVT) of (E/Z)‐7, (E/Z)‐8, and (E)‐9 give rise to intramolecular reactions of the siloxycarbene intermediates. Thus, FVT (520°) of (E)‐ and (Z)‐7 selectively leads to the enol silyl ethers 32 and (E)‐33, respectively, arising from carbene insertion into an allylic C–‐H bond. FVT of (E/Z)‐8 (560°) and (E)‐9 (600°) affords the trienol silyl ethers 34A + B and the cyclic silyl ethers 37A + B, respectively, which are formed by CH insertion of the siloxycarbenes. As further products of (E)‐8 and (E)‐9, the bicyclic enol ethers 35 and 36 are formed, presumably via siloxycarbene addition to the cyclohexene CC bond.
Neue Diterpenoide aus Blattdrüsen einer Plectranthus sp. aus Rwanda
Authors: Alder Alfredo Carlos , Rüedi Peter , Prewo Roland , Bieri Jost H. , Eugster Conrad Hans 
Published: December 2004

Novel Diterpenoids from Leaf‐Glands of a Plectranthus sp. from RwandaMore than 20 highly modified abietanoid compounds belonging to 6,7‐dioxocoleons, serveral kinds of royleanones, spirocoleons, extended quinones, quinone methides, and 1,4‐phenanthraquinones have been isolated from a Plectranthus sp. from the borders of Lake Kiwu (Rwanda). The structure of plectranthon A (1), a 5,7,8‐trimethyl‐1,4‐phenanthraquinone, has been confirmed by an X‐ray analysis of its p‐bromobenzoate. It is twisted around the C(4)–C(5) moiety; this fact renders the molecule chiral. Notable features of the hydroxylation pattern in all of the isolated compounds are: (a) a predominant hydroxylation at C(16) (abietan numbering) leading to the (15S)‐configuration of the 2‐hydroxy‐l‐methylethyl side‐chain and to the (13S, 15R)‐configuration of the derived spirocyclopropanes and to the derived (S)‐2‐hydroxypropyl side‐chain; (b) the 6β,7α‐dihydroxylation which, together with further hydroxylations at C(3) and/or C(2), are considered as a prerequisite for the formation of the conjugated system extending over rings A, B and C (e.g. in the coleons E and F), hence allowing a complete aromatization of the basic ring skeleton. The reasons for these extensive dehydrogenation and oxygenation reactions that cost the plant a great many of oxidation equivalents are not clear. Presumably, these modifying reactions preceed the degradation of the ring system.
X‐Ray Crystallographic and MO Studies on the Conformation of Corynoline and the Related Compounds
Authors: Kamigauchi Miyoko , Noda Yuko , Takao Narao , Ishida Toshimasa , Inoue Masatoshi 
Published: December 2004

AbstractThe crystal structure of (±)‐corynoline (1) has been determined by X‐ray diffraction methods. The rings B and C form the half‐chair and the twist‐half‐chair conformations, respectively. The B/C ring conjunction exists in an anti‐cis conformation, with a N …︁ HO intramolecular H‐bond. Conformational energy calculation by the CNDO/2 method show that the conformations of 1, (+)‐chelidonine (2), and their acetates, observed in crystal structures, are all in the one of total energy minimum.
Anion Selectivities of Triorganyltin Acetates and Halides in Solvent Polymeric Membranes
Authors: Wuthier Urs , Pham Hung‐Viêt , Rusterholz Bruno , Simon Wilhelm 
Published: December 2004

AbstractA series of triorganyltin compounds of the type R3SnY and RR2SnY has been studied in view of their anion selectivities exhibited in solvent polymeric membranes. A large variety of selectivity patterns has been observed first by varying the concentration of a given ionophore in the membrane phase, and second by using ionophores which differ in the organic substituents R on the Sn centre. With more space consuming substituents R, the observed selectivity patterns become more and more similar to that of a blank membrane, suggesting steric hindrance for the pentacoordination of the corresponding ionophores by sample anions.
Struktur von Edulon A
Authors: Künzle Josef Max , Rüedi Peter , Prewo Roland , Eugster Conrad Hans 
Published: December 2004

Structure of Edulon ABased on new chemical reactions and an X‐ray analysis of the derived camphanic ester 2e, edulon A has been shown to have the structure 2a, i.e. (10bS, 1′S)‐8‐(2′‐acetoxy‐1′‐methylethyl)‐2,4,6, 10b‐tetrahydro‐7,9, 10‐trihydroxy‐3, 10b‐dimethyl‐1H‐5‐oxaaceanthrylene‐4,6‐dione. Therefore, it is not a 2H‐1‐oxapyrene as previously assumed, but a derivative of the novel 4H‐5‐oxaaceanthrylene skeleton.