bluuebunny/crossref_metadata_2025 huggingface dataset:
A Norrish Type I cleavage in the photolysis of a steroidal α,β‐unsaturated δ‐lactone. Photochemical Reactions. XIV [1]
Authors: Cánovas Antonio , Bonet Juan‐Julio
Published: December 2004

The UV. irradiation of 17 β‐acetoxy‐4‐oxa‐5 α‐androst‐1‐en‐3‐one (1) yields A,B‐diseco‐steroids originating from a Norrish I process of the lactone function.
A structural investigation of the antibiotic rubiflavin. Preliminary communication
Authors: Nadig Heinz , Séquin Urs
Published: December 2004

Rubiflavin is shown to be a mixture of antibiotics. The main components have been named rubiflavin A (3) and rubiflavin B (2) and are identified by NMR. spectroscopy as desacetylpluramycin A and kidamycin, respectively.
Nucleoside und Nucleotide. Teil 15. Synthese von Desoxyribonucleosid‐monophosphaten und ‐triphosphaten mit 2(1H)‐Pyrimidinon, 2(1H)‐Pyridinon und 4‐Amino‐2(1H)‐pyridinon als Basen
Authors: Kohler Peter , Wachtl Michael , Tamm Christoph
Published: December 2004

Nucleosides and Nucleotide. Part 15. Synthesis of Deoxyribonucleoside Monophosphates and Triphosphates with 2(1H)‐Pyrimidinone, 2(1H)‐Pyridinone and 4‐Amino‐2(1H)‐pyridinone as the Bases

The phosphorylation of the modified nucleosides 1‐(2′‐deoxy‐β‐D‐ribofuranosyl)‐2(1 H)‐pyrimidinone (Md, 4), 4‐amino‐1‐(2′‐deoxy‐β‐D‐ribofuranosyl)‐2(1 H)‐pyridinone (Zd, 6) and the synthesis of 1–2′‐deoxy‐β‐D‐ribofuranosyl‐2(1 H)‐pyrimidinone‐5′‐O‐triphosphate (pppMd, 1), 1‐(2′‐deoxy‐β‐Dribofuranosyl)‐2(1 H)‐pyridinone‐5′‐O‐triphosphate (pppIId, 2), and 4‐amino‐1‐(2′‐deoxy‐βD‐ribofuranosyl)‐2(1 H)‐pyridinone‐5′‐O‐triphosphate (pppZd, 3) are described. The nucleoside‐5′‐monophosphates pMd (5) and pZd (7) were obtained by selective phosphorylation of Md (4) and Zd (6), respectively, using phosphorylchloride in triethyl phosphate or in acetonitril. The reaction of pMd (5) pII d (8) or pZd (7) with morpholine in the presence of DCC led to the phosphoric amides 9, 10 and 11, respectively, which were converted with tributylammonium pyrophosphate in dried dimethylsulfoxide to the nucleoside‐5′triphosphates 1, 2 and 3, respectively.
The Synthesis of an O‐2‐Isooxacephem
Authors: Hakimelahi Gholam Hosien , Just George , Ugolini Antonio
Published: December 2004

The synthesis of an iso‐oxacephem is described. Reaction of methanesulfonyl chloride with hydroxyaldylmalonates can form sulfones or sulfonates, their ratio varying with the basicity of the tertiary amine used in the sulfonation.
Regioselective Synthesis of 2‐oxo‐2,8‐dihydro‐[l,2,4] oxadiazolo [2,3‐a]pyrimidine‐7‐carbamates: A New Class of Antihypertensive Peripheral Vasodilators
Authors: Muller Jean‐Claude , Ramuz Henri
Published: December 2004

The synthesis of new 2‐oxo‐2,8‐dihydro‐[l,2,4]‐oxadiazoo‐[2,3‐a] pyrimidine‐carbamates 3 described in this paper is based upon a regioselective heterocyclization of the pyrimidine‐2,6‐bis (alkoxycarbonylamino) N‐oxides 4. Structural and mechanistic aspects of that cyclizalion are discussed.
Structural Analysis of Eukovoside, A New Phenylpropanoid Glycoside from Euphrasia rostkoviana HAYNE
Authors: Sticher Otto , Salama Osama , Chaudhuri Ratan K. , Winkler Tammo
Published: December 2004

The isolation and structure determination of a phenylpropanoid glycoside from Euphrasia rostkoviana HAYNE, named eukovoside (1). are reported.
Chaetoglobosin L, a New Metabolite of Diplodia macrospora
Authors: Probst Alessandro , Tamm Christoph
Published: December 2004

From cultures of Diplodia macrospora a new metabolite of the cytochalasan family, Chaetoglobosin L (3), has been isolated and its structure elucidated together with the known compounds diplosporin (1) and Chaetoglobosin K (2).
2′‐Deoxy‐β‐D‐ribofuranosides of N6‐Methylated 7‐Deazaadenine and 8‐Aza‐7‐deazaadenine: Solid‐phase synthesis of oligodeoxyribonucleotides and properties of self‐complementary duplexes
Authors: Seela Frank , Kaiser Klaus , Bindig Uwe
Published: December 2004

The syntheses of 7‐deaza‐N6‐methyladenine N9‐(2′‐deoxy‐β‐D‐ribofuranoside) (2) as well as of 8‐aza‐7‐deaza‐N6‐methyladenine N8− and N9−(2′‐deoxyribofuranosides) (3 and 4, resp.) are described. A 4,4′‐dimeth‐oxylritylation followed by phosphitylation yielded the methyl phosphoramidites 12–14. They were employed together with the phosphoramidite of 2′‐deoxy‐N6v‐methyladenosine (15) in automated solid‐phase oligonucleotide synthesis. Alternating or palindromic oligonucleotides derived from d(A‐T)6 or d(A‐T‐G‐C‐A‐G‐A*‐T‐C‐T‐G‐C‐A) but containing one methylated pyrrolo[2,3‐d]pyrimidine or pyrazolo[3,4‐d]pyrimidine moiety in place of a N6‐methylaminopurine (A*) were synthesized. Melting experiments showed that duplex destabilization induced by a N6‐Me group of 2′‐deoxy‐N6‐methyladenosine is reversed by incorporation of 8‐aza‐7‐deaza‐2′‐deoxy‐N6‐meihyladenosine, whereas 7‐deaza‐2′‐deoxy‐N6‐methyladenostne decreased the Tm value further. Regiospecific phosphodiester hydrolysis of d(A‐T‐G‐C‐A‐G‐m6A‐T‐C‐T‐G1‐C‐A) by the endodeoxyribonuclease Dpn I, yielding d(A‐T‐G‐C‐A‐G‐m6A) and d(pT‐C‐T‐G‐C‐A), was prevented when the residue c7m6Ad (2), c7m6z8Ad (3), or c7m6z8Ad′ (4) replaced m6Ad (1) indicating that N(7) of N6‐methyladenine is a proton‐acceptor site for the endodeoxyribonuclease.
Silicon‐Directed Regio‐ and Enantioselective Synthesis of α‐Hydroxy‐ketones Preliminary Communication
Authors: Lohray Braj B. , Enders Dieter
Published: December 2004

α‐Silylated ketones (S)−2 (ee ≥ 98%), easily available through silylation or silylation/alkylation from ketones 1 using the (−)‐(S)‐1‐amino‐2‐(methoxymethyl)pyrrolidine (SAMP)−/(+)‐(R)‐1‐amino‐2‐(methoxymethyl)pyrrolidine (RAMP)‐hydrazone method, are oxidized to give α‐hydroxy‐ketones (R)−5 of high enantiomeric purity (ee ≥ 98%) and in good overall yields (51‐70%). The key step of the procedure is the silicon‐directed diastereoselective oxidation of the corresponding silyl enol ethers of (S)−2, with m‐chloroperbenzoic acid or 3‐phenyl‐2‐(phenylsulfonyl)oxaziridine, followed by flash chromatography and desilylation.
Synthèse du virensate de méthyle
Authors: Pulgarin César , Tabacchi Raffaele
Published: December 2004

Synthesis of Methyl Virensate

The synthesis of methyl virensate (=methyl 4‐formyl‐3,8‐dihydroxy‐1,6,9‐trimethyl‐11‐oxo‐11H‐dibenzo‐[b, e][1,4]dioxepin‐7‐carboxylate; 18) by the condensation of the substituted β‐orcinol and orcinol units 9 and 10 followed by formylation and demethylation of the depsidone 13 is described.
The Infrared Multiphoton‐Dissociation Spectra of Bromopropene Isomeric Cations
Authors: Gäumann Tino , Riveros José M. , Zhu Zhiqing
Published: December 2004

The infrared quasi‐resonance stepwise‐multiphoton‐dissociation spectra of the molecular ions of 1‐bromo‐propene, 2‐bromopropene, 3‐bromopropene, and bromocyclopropane have been obtained at selected wavelengths between 9. 2 and 10. 7 μm in a Fourier ‐transform mass spectrometer. The resulting spectra and the photo fragmentation kinetics suggest that these molecular ions retain their identity upon ionization, and can, thus, provide fingerprint spectral identifications for the ions.
The chemistry of coumarin derivatives, part 2. Reaction of 4‐hydroxycoumarin with α,β‐unsaturated aldehydes
Authors: Appendino Giovanni , Cravotto Giancarlo , Tagliapietra Silvia , Nano Gian Mario , Palmisano Giovanni
Published: December 2004

4‐Hydroxycoumarin (= 4‐hydroxy‐2H‐1‐benzopyran‐2‐one) reacts with enals to give 1,2‐ or 1,4‐addition products, depending on the nature and relative location of the substituents on the olefinic double bond (Scheme 2). The resulting adducts further react intra‐ or intermolecularly, affording dimeric coumarins or pyranocoumarins in the case of 1,2‐addition and acetalic pyranocoumarins in the case of 1,4‐addition. With enals bearing alkyl groups at C(β), 2H‐pyrano[3,2‐c]coumarins are the only products formed, and the reaction represents an easy and straightforward entry into this class of recently described biologically active natural products.
Configuration‐Odor Relationships in 5β‐Ambrox
Authors: Escher Sina , Giersch Wolfgang , Niclass Yvan , Bernardinelli Gérald , Ohloff Günther
Published: December 2004

The four possible A/B cis‐fused diastereoisomers of Ambrox® have been synthesized and their configurations and conformations established by X‐ray and NMR analysis. Only 5β‐ambrox (= 1,2,3a,4,5,5β,6,7,8,9,9a,9bα‐dodecahydro‐3aβ,6,6,9aβ‐tetramethylnaphtho[2,1‐b]furan; 5) has an odor quality comparable to Ambrox®. The 1,3‐synperiplanar/diaxial conformation of the substituents at C(8) ( = C(3a)) and C(10) (= C(9a)) has thus been confirmed to be a compulsory structure element for the particular odor.
Bicyclo[4.2.0]octa‐1,3,5‐triene: 2‐Mono‐ and 2,5‐Disubstituted Derivatives via Highly Regioselective Lithiation of Its Cr(CO)3 Complex and via Reductive Silylation/Oxidation
Authors: Kündig E. Peter , Ferret Celia , Rudolph Bruno
Published: December 2004

Treatment of [η6‐(bicyclo[4.2.0]octa‐1,3–5 triene)]tricarbonylchromium(0) (2) with BuLi or lithium 2,2,6,6‐tetramethylpiperidinide (TMPLi) gives rise to a highly regioselective deprotonation at C(2). Subsequent reaction with electrophiles (6 examples) gives [η6‐(2‐R‐bicyclo[4.2.0]octa‐1,3,5‐triene)]tricarbonylchromiurn complexes 3 and 5–9 in moderate (RI, 50%; RCHO, 67%) to good (RMe, D, SiMe3, CO2Me, > 80%) yield (Scheme 1). Analogous reactions with tricarbonyl (η6‐indane)chromium (10) give mixtures of complexes substituted at C(4) and C(5) (Scheme 2). In 10, deprotonation β to the ring junction is strongly favoured with the bulky base TMPLi. Double lithiation/electrophile additions to 2 give access to [η6‐(2‐R′‐5‐R″‐bicyclo[4.2.0]octa‐1,3,5‐triene)]tri‐carbonylchromium complexes (e.g. 13 (R′R″Me3Si) and 14 (R′Me3Si, R″CHO)) as single products. The Cr(CO)3 group can be easily removed by oxidation (I2, Ce(IV), O2/light; 2 examples each) to give the free arenes. Base‐catalyzed (CsF, DMF/D2O) deuterodesilylation of 13 yields the [(2,5‐2H2)bicyclo[4.2.0]octa‐1,3,5‐triene]chromium complex 15, and treatment of 2,5‐bis(trimethylsilyl) compound 16 with CF3COOD gives the 2,4‐dideuterated 17. Compound 16 is also accessible more directly via reductive silylation/oxidation of bicyclo[4.2.0]octa‐1,3,5‐triene (1). Stereoselective base‐catalyzed (t‐BuOK.) H/D exchange of the benzylic H‐atoms. opposite to the Cr(CO)3 moiety in 2 takes place rapidly in (D6)DMSO, but benzylic functionalization via this route remains elusive.
Coenzyme F430 from Methanogenic Bacteria: Complete Assignment of Configuration Based on an X‐Ray Analysis of 12,13‐Diepi‐F430 Pentamethyl Ester and on NMR Spectroscopy
Authors: Färber Gerald , Keller Walter , Kratky Christoph , Jaun Berhard , Pfaltz Andreas , Spinner Christoh , Kobelt André , Eschenmoser Albert
Published: December 2004

The structure of a derivative of coenzyme F430 from methanogenic bacteria, the bromide salt of 12,13‐diepi‐F430 pentamethyl ester (5, X = Br), was determined by X‐ray structure analysis. It reveals a more pronounced saddle‐shaped out‐of‐plane deformation of the macrocycle than any hydroporphinoid Ni complex investigated so far. The crystal structure confirms the constitution proposed for coenzyme F430 (2) and shows that in the epimer 5, the three stereogenic centers in ring D, C(17), C(18), and C(19), have the (17S)‐, (18S)‐, and (19R)‐configuration, respectively. Deuteration and 2D‐NMR studies independently demonstrate that native coenzyme F430 (2) has the same configuration in ring D as the epimer 5. Therefore, our original tentative assignment of configuration at C(19) and C(18) [1] has to be reversed. This completes the assignment of configuration for all stereogenic centers in coenzyme F430, which has the structure shown in Formula 2.
Condensation of 2,3‐Di(methylidene)‐7‐oxabicyclo[2.2.1]heptane Derivatives into Dicarbonyl[η3:η3‐octa‐2,6‐diene‐1,8‐diyl]iron Complexes with Nonacarbonyldiiron. Crystal Structure of (1RS,2RS,3RS,4SR,5RS,6SR,1′RS,2′RS,3′RS,4′SR,5′RS,6′SR)‐Dicarbonyl‐{(2,3,C‐η:2′,3′,C‐η)‐2,2′‐ethylene‐5,5′,6,6′‐tetrakis[(methanesulfonyloxy)‐methyl]‐3,3′‐di(methylidene)‐bis[7‐oxabicyclo[2.2.1]hept‐2‐yl]}iron
Authors: Araki Shuki , Vogel Pierre , Blanc Eric , Chapuis Gervais , Schenk Kurt
Published: December 2004

The reactions of [Fe2(CO)9] with 2‐exo,3‐exo‐bis(chloromethyl)‐5,6‐di(methylidene)‐7‐oxabicycio[2.2.1]‐heptane (5) and with 5,6‐di(methylidene)‐7‐oxabicyclo[2.2.1]heptane‐2‐exo,3‐exo‐dimethyl bis(methanesulfonate) (6) afforded, together with the corresponding [exo‐Fe(CO)3(1,3‐diene)] complexes 7 and 8, the products of dimerization in the form of stable [Fe(CO)2{(1,2,3‐η:6,7,8‐η)‐octa‐2,6‐diene‐1,8‐diyl}] complexes 9 and 10, respectively, with high stereoselectivity. The structure of 10 was established by means of single‐crystal X‐ray diffraction.
Chiral Acylsilanes in Organic Synthesis. Diastereoselective 1,2‐Additions to Racemic Alkoxymethyl‐Substituted Acylsilanes
Authors: Bienz Stefan , Chapeaurouge Alexander
Published: December 2004

The synthesis of the three alkoxymethyl‐substituted acyisilanes 1–3 is described (Schemes 1 and 2). Their reactions with NaBH4 as well as PhLi gave the corresponding alcohols with moderate to good diastereoisomeric induction (up to 78% de; see Table), depending upon the solvent used (Scheme 3). The results indicate that in Et2O, the reactions with PhLi proceed via 6‐membered chelates (see C in Scheme 4) leading to the products with high de's (74–78%). In THF, these chelates are not formed, and as a consequence, the additions take place with reversed and lower stereoselectivities (34–50% de).
1,2‐Stereoinduction in Radical Reactions: Stereoselective Synthesis of 2‐Alkyl‐3‐hydroxybutanoates
Authors: Bulliard Michel , Zehnder Margareta , Giese Bernd
Published: December 2004

Radical addition to 2‐cyclohexyl‐5‐methylidene‐6‐methyl‐1,3‐dioxan‐4‐one (2) affords stereoselectively 5,6‐trans‐products trans‐3. The size of the radical has no influence on the selectivity. These trans‐acetals are converted into threo‐3‐hydroxy‐butanoates 4. Methyl 2‐methylidene‐3‐[(tert‐butyl)diphenylsilyloxy]butanoate (5), treated under the same conditions, leads mainly to the erythro‐isomer of 4 after deprotection. An influence of the steric bulkyness of the radical is observed. The stereochemical course of the reactions is discussed.
Catalytic One‐Pot Osmylation of Cyclohexadienes: Stereochemical and conformational studies of the resulting polyols
Authors: Tschamber Théophile , Backenstrass Frédérique , Fritz Hans , Streith Jacques
Published: December 2004

Catalytic double osmylation is described for a series of cyclohexadienes in acetone/H2O in the presence of the co‐oxidant N‐methylmorpholine N‐oxide (NMO). The formation of polyols occurred stereospecifically with cyclohexadienes 3,7, and 11a, leading thereby to tetrols 5a, and 9a and to allo‐inositol (14a), respectively. To the contrary, trans‐cyclohexadiene‐diol 15a gave a mixture of the stereoisomeric inositols 18a (epi), 19a (neo), and 20a (chiro). High‐field NMR let to clearcut conformational analyses of the polyhydroxylated derivatives.
Synthèse et propriétés photochromiques de 1, 3‐dihydrospiro[2H‐indole‐2,3′‐[3H]pyrimido[5,4‐f][1,4]benzoxazines] et de 1,3‐dihydrospiro[2H‐indole‐2,7′‐[7H]thiazolo[5,4‐f][1,4]benzoxazines]
Authors: Tardieu Pascale , Dubest Roger , Aubard Jean , Kellmann Arlette , Tfibel Francis , Samat André , Gugliemetti Robert
Published: December 2004

Synthesis and Photochrmic Characteristics of 1,3‐Dihydrospiro[2H‐indole‐2,3′‐[3H‐]pyrimido[5,4‐f][1,4]benzoxazines] and 1,3‐Dihydrospiro[2H‐indole‐2,7′[7H]thiazolo[5,4‐f][1,4]benzoxazines]

Two new series of 1,3‐dihydrospiro[2H‐indole‐ozazine] derivatives were synthesized, the 1,3‐dihydrospiro[2H‐indole‐2,3′‐[3H]pyrimido[5,4]pyrimido[5,4‐f][1,4]benzoxaines] 4‐10 and the 1,3‐dihydrospiro[2H‐indole2,7′‐[7H]thiazolo‐[5,4‐f][1,4]benzoxaines] 11–17. These series extend the available range of photochromic properties (rate constant of thermal bleaching, UV/VIS spectrum of the opened coloured form, and photocoloration yield), an interesting feature of variable‐transmission materials. The synthesis of these compounds (Scheme 1) required the preliminary synthesis of intermediate β‐hydroxy‐α‐nitrosotherocycles 18 and 19 (Scheme 2). Important amounts of a coloured, non‐photochromic, stable secondary product (See 20) were found in the condensation in the spiro[indole‐thiazolobenzoxazine] series. The photochromic characteristics of the new derivatives were determined using a flash‐photolysis apparatus coupled to a fast‐scanning spectrometer. The role of the heteroatoms in the oxazine moiety and the role of substitutents in the indole moiety were investigated quantitatively through the study of the photochromic properties and the solvent effects. The presence of an S‐atom gives rise to interesting properties which open up new prospects for synthesis and application.
Pterin Chemistry. Part 92.. Loading experiments with 6α,β‐tetrahydro‐L‐[3′‐2H1] biopterin
Authors: Adler Carmen , Curtius Hans‐Christoph , Wetzel Erich , Viscontini Max , Giudici Tullio A. , Blaskovics Milan , Rolland Marie O. , Guibaud Pierre
Published: December 2004

6α,β‐Tetrahydro‐L‐[3′‐2H1]biopterin ([3′‐2H1]‐1) was administered orally to two primapterinuric patients in order to investigate the biosynthetic pathway of 7‐substituted pterins in humans. L‐Primapterin (2) and L‐biopterin were isolated from urine after loading and measured by GC/MS. L‐Biopterin and L‐primapterin were labelled with 2H to an equal extent. From this result, one can conclude that L‐primapterin is formed from tetrahydro‐L‐biopterin, very probably via an intramolecular rearrangement.
Nucleosides. Part L.. Structure of lumazine N1‐(2′‐deoxy‐D‐ribonucleosides) ( = 1‐(2′‐deoxy‐D‐ribofuranosyl)pteridine‐2,4(1H,3H)‐diones): A revision of the anomeric configuration
Authors: Cao Xiaodong , Pfleiderer Wolfgang , Rosemeyer Helmut , Seela Frank , Bannwarth Willi , Schönholzer Peter
Published: December 2004

The anomeric configuration of the glycosidic bond in lumazine N1‐(2′‐deoxy‐D‐ribonucleosides) 1–6 was investigated by NOE difference spectroscopy. The former configurational assignment of the α ‐ and β ‐D‐anomers 1 and 2, 3 and 4, and 5 and 6, respectively, has to be reversed to be in agreement with the physical data. Additional proof is presented by X‐ray analysis of 3 and 6. Chemical interconversions of 1‐(2′‐deoxy‐β‐D‐ribofuranosyl)‐6,7‐diphenyllumazine (6) into 2,3′ ‐anhydrolumazine 2′‐deoxyribonucleosides 16 and 17 are also in agreement with the revised anomeric configuration.
Stereoselectivity in Reactions of Metal Complexes. Part XIV.. Use of circular dichroism to determine the stereoselective formation of [M(his)2] and [M(PhEt‐sal)2] (M = Ni2+, Cu2+, his = histidine, PhEt‐sal = N‐(1‐phenylethyl)salicylaldimine)
Authors: Bernauer Klaus , Bourqui Stephanie , Huti‐Cleary Deirdre , Warmuth Ruth
Published: December 2004

The stereoselective formation of the 1:2 complexes [M(his)2] and [M(PhEt‐sal)2] (M = Ni2+, Cu2+, PhEt‐sal = N‐(1‐phenylethyl)salicylaldimine) has been determined by circular dichroism (CD) measurements. Stereoselectivity, defined as S = Kmeso/2Krac' has been found to be 2.48 for [Ni(his)2], corresponding to a 21% excess of the mixed species relative to the statistical amount. This value is temperature‐independent between 15 and 35°. Whereas the absence of stereoselectivity in the formation of [Cu(prol)2] is confirmed, weak stereoselectivity is observed for [Cu(his)2] (2% excess of the mixed species). The CD intensity of the latter complex strongly depends on temperature and decreases by 12%, when the temperature is increased from 15 to 35°. Small but significant stereoselectivity is found for the formation of the Schiff‐base complexes [Ni(PhEt‐sal)2] and [Cu(PhEt‐sal)2] in acetone with 1.0% and 2.4% excess, respectively, of the mixed species over the statistical value.
Generation of ‘Bare’ FeF+ by CF Bond Activation in the Gas Phase and Evaluation of Thermochemical Data. Short communication
Authors: Schröder Detlef , Hrušák Jan , Schwarz Helmut
Published: December 2004

The title compound FeF+ has been generated in a Fourier‐transform ion‐cyclotron‐resonance mass spectrometer via CF bond activation by reacting hexafluorobenzene with bare FeO+. Bracketing experiments provide a bond‐dissociation energy (BDE) for FeF+ of 86 < BDE < 101 kcal/mol. High‐level CAS‐MCSCF pseudopotential ab initio calculation, including 501036 electronic configurations, predict a BDF(Fe+F) of 100.9 kcal/mol.
Ru‐Catalyzed Heptalene Formation from Azulenes and Dimethyl Acetylenedicarboxylate
Authors: Rippert Andreas Johannes , Hansen Hans‐Jürgen
Published: December 2004

It is shown that azulenes react with dimethyl acetylenedicarboxylate (ADM) in solvents such as toluene, dioxan, or MeCN in the presence of 2 mol‐% [RuH2(PPh3)4] already at temperatures as low as 100° and lead to the formation of the corresponding heptalene‐1,2‐dicarboxylates in excellent yields (Tables 1 and 2). The Ru‐catalyzed reaction of ADM with 1‐(tert‐butyl)‐4,6,8‐trimethylazulene (31) takes place even at room temperature, yielding the primary tricyclic addition product 32 and its thermal retro‐Diels‐Alder product dimethyl 4,6,8‐trimethylazulene‐1,2‐dicarboxylate (21; Scheme 4). At 100° in MeCN, 32 yields 90% of 21 and only 10% of the corresponding heptalene. These observations demonstrate that [RuH2(PPh3)4] catalyzes the first step of the thermal formation of heptalenes from azulenes and ADM which occurs in apolar solvents such as tetralin or decalin at temperatures > 180° (cf. Scheme 1).
Thermal Reaction of Azulene and Some of Its Symmetrically Substituted Methyl Derivatives with Dimethyl Acetylenedicarboxylate
Authors: Chen Yi , Hansen Hans‐Jürgen
Published: December 2004

It is shown that azulene (1) and dimethyl acetylenedicarboxylate (ADM) in a fourfold molar excess react at 200° in decalin to yield, beside the known heptalene‐ (5) and azulene‐1,2‐dicarboxylates (6), in an amount of 1.6% tetramethyl (1RS,2RS,5SR,8RS)‐tetracyclo[6.2.2.22,501,5]tetradeca‐3,6,9,11,13‐pentaene‐3,4,9,10‐tetracarboxylate(‘anti’‐7) as a result of a SHOMO (azulene)/LUMO(ADM)‐controlled addition of ADM to the seven‐membered ring of 1 followed by a Diels‐Alder reaction of the so formed tricyclic intermediate 16 (cf. Scheme 3) with a second molecule of ADM. The structure of ‘anti’‐7 was confirmed by an X‐ray diffraction analysis. Similarly, the thermal reaction of 5,7‐dimehtylazulene (3) with excess ADM in decalin at 120° led to the formation of ca. 1% of ‘anti’‐ 12, the 7,12‐dimethyl derivative of‘anti’‐7, beside of the corresponding heptalene‐ 10 and azulene‐1,2‐dicaboxylated (cf Scheme 2). The introduction of Me groups at C(1)and C(3)of azulene (1) and its 5,7‐dimethyl derivative 3 strongly enhance the thermal formation of the corresponding tetracyclic compound. Thus, 1,3‐dimethylazulene (2) in the presence of a sevenfold molar excess of ADM at 200° yielded 20% of ‘anti’‐9 beside an equal amount of dimethyl 3‐mehtylazulene‐1,2‐dicarboxylate (8;cf. Scheme 1), and 1,3,5,7‐tetramethylazulene (4) with a fourfold molar excess of ADM AT 200° gave a yield of 37% of‘anti’‐15 beside small amount of the corresponding heptalene‐ 13 and azulene‐1,2‐dicarboxylates 14 (cf.Scheme 2).
Synthesis and Biological Evaluation of 14‐Alkoxymorphinans. Part 9. 14‐O‐ethyl‐5‐methylnaltrexone, and opioid antagonist with unusual selectivity
Authors: Schmidhammer Helmut , Schratz Andrea , Schmidt Charlotte , Patel Dinesh , Traynor John R.
Published: December 2004

14O‐Ethyl‐5m‐ethylnaloxone (7) and 14O‐ethyl‐5‐methylnaltrexone (8) have been prepared starting from 14O‐ethyl‐5‐methyloxycodone (9) in several steps. Both, 7 and 8, were found to be opioid antagonists in vitro and in vivo. Compound 7 exhibited some selectivity for μ opioid receptors, whereas compound 8 did not show selectivity for any of the receptor types. In the AcOH‐writhing antagonism test, 8 was not able to antagonize morphine‐induced antinociception, but antagonized fentanyl‐ and sufentanil‐induced antinociception.
Glyconothio‐O‐lactones. Part I. Preparation and reactions with nucleophiles
Authors: Hürzeler Marianne , Bernet Bruno , Vasella Andrea
Published: December 2004

Furanoid and pyranoid glyconothio‐O‐lactones were prepared by photolysis ofS‐phenacyl thioglycosides or by thermolysis ofS‐glycosyl thiosulfinates, which gave better results than the thionation of glyconolactones withLawesson's reagent. Thermolysis of the thiosulfinates obtained from the dimannofuranosyl disulfide7or the manofuranosyl methly disulfide8(Scheme 2) gave low yields of the thio‐O‐lactone2. However, photolysis of theS‐phenacyl thioglycoside6obtained byin situalkylation of the thiolato anion derived from5led in 78–89% to2. Similarly, the dithiocarbonate10was transformed,via11a, into theribo‐thio‐O‐lactone12(79%). Thermolysis of the peracetylated thiosulfinates14(Scheme 3) led to the intermediate thio‐O‐lactone15, which underwent facile β‐elimination of AcOH (→16, 75%) during chromatography. The perbenzylatedS‐glucopyranosyl dithiocarbonate18(Scheme 4) was transformed either into theS‐phenacyl thioglucoside19or into a mixture of the anomeric methyl disulfides21a/b. Whereas the photolysis of19led in moderate yield to 2‐deoxy‐thio‐O‐lactone20, oxidation of21band thermolysis of resulting thiosulfinates gave the thio‐O‐lactone4(79%), which was transformed into20(36%) upon photolysis. The pyranoidmanno‐thio‐O‐lactone26was prepared in the same way and in good yields from22viathe dithiocarbonate24band the disulfide25. The ring conformations of the δ‐thio‐O‐lactones, flattened4C1for15and4andB2,5for26, are similar to the ones of the O‐analogous oxo‐glyconolactones. The reaction of2(Scheme 5) with MeLi and then with MeI gave the thioglycoside27(29%) and the dimeric thio‐O‐lactone29(47%). The analogous treatment of2with lithium dimethylcuprate (LiCuMe2) and MeI led to a 4:1 mixture (47%) of31and27. The structure of2was proven by an X‐ray analysis, and the configuration at C(6) and C(5) of29was deduced from NOE experiments. Substitution of MeI by CD3I led to the CD3S analogues of27,29, and31,i.e.28,30, and32, respectively, evidencing carbophilic addition and ‘exo’‐attack on2by MeLi and the enethiolato anion derived from2. The preferred ‘endo’‐attack of LiCuMe2is rationalized by postulating a single‐electron transfer and a diastereoselective pyramidalization of the intermediate radical anion.
Nachbargruppeneffekte in der Gas‐Phase: Intramolekulare Deacetalisierung von Hydroxyacetalen unter den Bedingungen der chemischen Ionisation
Authors: Matile Stefan , Janowitz Agnes , Ghirlanda Sandro , Lorenzi‐Riatsch Annalaura , Horni Albert , Moricz Attila , Bienz Stefan , Bild Norbert , Woggon Wolf‐Dietrich , Hesse Manfred
Published: December 2004

Neighboring‐Group Participation in the Gas Phase: Intramolecular Deacetalization of Hydroxyacetals under the Conditions of Chemical Ionization

Herrn Prof. Dr. Christoph Tamm zum 70. Geburtstag gewidmet

Under the conditions of chemical ionization (NH3, isobutane, ND3), hydroxyacetals do not show the expected [M + H+] signal, but the peak corresponding to the loss of the alcohol component of the acetal. This reaction is dependent on the presence of the OH group in the vicinity of the acetal and on the ring size of the heterocycle being formed. M+· is detected to a small extent as a consequence of charge exchange during chemical ionization.
Nucleotide Coupling in Reverse Micelles
Authors: Böhler Christof , Luisi Pier Luigi , Bannwarth Willi , Giustini Mauro
Published: December 2004

Nucleotide coupling was investigated in reverse micelles formed by (cetyl)trimethylammonium bromide (CTAB), in hexane/pentan‐1‐o1. In particular, the coupling of 2′ ‐deoxy‐5′‐O‐methylcytidine 3′ O‐phosphate, prepared by phosphoramidite chemistry, with 5′‐amino‐5‐deoxythymidine was studied in the presence of a H2O‐soluble carbodiimide at (wo) = 11 and 22 (wo=[H2O]/[CTAB]). The effect of wo on the reaction rate was investigated. A solid‐phase strategy was developed for the synthesis of 2′‐deoxy‐5′O‐methyl‐cytidyl‐(3′‐5′)‐5′‐amino‐5′deoxythymidine. The nucleotide coupling yieldig the expected product occurred readily in reverse micelles. Nucleotide coupling is thus possible in reverse micelles, and this is discussed in connection with the micellar self‐replication program.
Redetermination of the Crystal Structure of the 1,2,4,7‐anti‐tetramethylbicyclo[2.2.1]heptan‐2‐yl cation at 110 K
Authors: Laube Thomas
Published: December 2004

The structure of the 1,2,4,7‐anti‐tetramethylbicyclo[2.2.1]heptan‐2‐yl cation (1) was redetermined by X‐ray crystal structure analysis of its Sb2F11 salt at 110 K (P21/c, R1 = 5.76%). The most important structural features of 1 are: C(1)C(2) = 1.409(9), C(1)C(6) = 1.710(8), and C(2)…C(6) = 2.113(9) Å and C(2)C(1)C(6) = 84.7(4)°. These results agree with those obtained earlier by other methods for the rapidly equilibrating, partially s̀‐delocalized 1,2‐dimethylbicyclo[2.2.1]heptan‐2‐yl cation (2). The detailed experimental procedure for the preparation of crystalline 1 · Sb2F11 and the crystal selection and mounting are described.
X‐Ray Structure Analysis of 15‐Apoviolaxanth‐15‐al
Authors: Linden Anthony , Eugster Conrad Hans
Published: December 2004

The X‐ray structure of 15‐apoviolaxanth‐15‐al ( = (1′S,2′R,4′S,2E,4E,6E,8E)‐9‐(1′,2′‐epoxy‐4′‐hydroxy‐2′,6′,6′‐trimethylcyclohexyl)‐3,7‐dimethylnona‐2,4,6,8‐tetraenal) is reported. The four symmetry‐independent molecules in the asymmetric unit are linked into X‐shaped spirals by intermolecular H‐bonds. Additional H‐bonds interconnect the spirals, forming wave‐like chains. The geometry of the polyene side chain possesses the same in‐plane bending observed for related retinal and carotenoid compounds. The polyene side chain deviates from planarity by twists of up to 10° about each bond; some of the largest twists are about CC bonds. The epoxycyclohexane ring possesses a distorted ‘C(3)‐sofa’ conformation. The torsion angles about the bond connecting the polyene chain to the cyclohexane ring are compared with equivalent torsion angles in molecules containing epoxide rings substituted with a π‐system in order to examine possible interactions between the epoxide group and the π‐system, either through pseudoconjugation, or through an interaction of the nonbonding orbitals of the epoxy O‐atom with the π‐orbitals of the polyene chain. The latter is considered to be more likely.
Synthesis of Chlorophyll a Labeled at C(32) from Pheophorbide a Methyl Ester
Authors: Fischer Rolf , Engel Norbert , Henseler Arthur , Gossauer Albert
Published: December 2004

[32‐14C]Chlorophyll a (10b) was synthesized from pheophorbide a methyl ester (5a) in a seven‐step partial synthesis. The key intermediate pheophorbide d methyl ester (6) was obtained by ozonolysis of the vinyl group of 5a in 91% yield. Selective reduction of the CHO group of 6 gave the corresponding alcohol 7, and conversion of the latter to the phosphonium bromide 8 yielded after Wittig reaction with [14C]paraformaldehyde, [32‐14C]pheophorbide a methyl ester (5b). The final transformation to the title compound was achieved by acid hydrolysis of 5b, esterification with natural phytol to [32‐14C]pheophytin a (9b), and eventual insertion of a Mg2+ ion.
Oncinotine‐Type Spermidine Alkaloids from Oncinotis tenuiloba. Transformation of N‐acetyloncinotin‐12‐one to N,N′‐diacetylinandenin‐12‐one
Authors: Doll Martin K.‐H. , Guggisberg Armin , Hesse Manfred
Published: December 2004

From extracts of Oncinotis tenuiloba STAPF, two novel polyamine alkaloids, oncinotin‐11‐one (5) and oncinotin‐12‐one (6), were isolated. Peracetylation of 6 provided the N‐acetyl derivative 11 as well as N,N′‐diacetylinandenin‐10‐en‐12‐one (12) due to a β‐elimination‐type side reaction resulting in ring enlargement of 11 (Scheme 1). Deuteration of 12 yielded 13, showing the same retention time as N,N′‐diacetylinandenin‐12‐one (14), when co‐HPLC was performed together with different keto‐isomeric N,N′‐diacetylinandeninones. Structure elucidation was extended by Schmidt degradation of 6 and N,N′‐diacetyl(10,11‐2H2)inandenin‐12‐one (13); the degradation products were identified by GC and ESI‐MS. The structure of 5 was proposed on the basis of spectroscopic means. Comparison of the spectroscopic data of 5 with those obtained from synthetic material as well as co‐HPLC of the N‐acetyl derivative 20 together with the corresponding synthetic compound revealed the identity of the substances and confirmed the structure of 5. Additionally, oncinotine (2) and neooncinotine (3) were isolated, separated, and identified with authentic samples by co‐HPLC of their N‐acetyl derivatives 8 and 9, respectively.
Theory‐enforced Re‐investigation of the Origin of the Large Metal–Carbon Bond Strength in PdCH2I+ and its reactions with unsaturated hydrocarbons
Authors: Schwarz Joseph , Schröder Detlef , Schwarz Helmut , Heinemann Christoph , Hrušák Jan
Published: December 2004

State‐of‐the‐art ab initio studies demonstrate that the reaction Pd+ + CH3I → PdCH2I+ + H. is endothermic by ca. 20 kcal/mol, which translates into a bond dissociation energy (BDE) of ca. 83 kcal/mol for the Pd+CH2I bond. This figure is in agreement with an experimental bracket of 68 kcal/mol < BDE(Pd+CH2I) < 92 kcal/mol. Based on these findings, the previously studied Pd+/CH3I system was re‐investigated, and double‐resonance experiments demonstrate that the formation of PdCH2I+ occurs stepwise via PdCH as a reactive intermediate. Further, ion/molecule reactions of PdCH2I+ with unsaturated hydrocarbons are studied, which reveal the formation of carbon–carbon bonds in the gas phase.
Oligosaccharide Analogues of Polysaccharides. Part 7. Synthesis of a monosaccharide‐derived monomer for amylose and cyclodextrin analogues
Authors: Bürli Roland , Vasella Andrea
Published: December 2004

The synthesis of monomers of type C (Scheme 1) is described. In a first approach, chloro‐acetyl‐addition to the dioxolane 2 (Scheme 2), followed by treatment of the resulting chlorides 3 (α‐D/β‐D 1:3) with excess AgOTf and Bu3SnCCSiMe3 gave the axial C‐alkynyl‐glycoside 4 (31%) and the C‐arylglycoside 5 (29%). The structure of the dialkyne 6, obtained by deacetylation of 4, was established by X‐ray analysis. The yield of the C‐alkynyl‐glycoside was slightly improved by protecting the C(4)‐ethynyl group as the triethysilyl derivative, but not by substituting the benzyl by allyl or 2,6‐difluorobenzyl groups. Silylation of the diol 1 with (chloro)diethyl[2‐(trimethylsilyl)ethynyl]silane (19) resulted in 90% of the monosilyl ether 20. HOC(3) of 20 should favor coordination of a Lewis acid to OC(6), and intramolecular, inverting acetal opening should lead to the product of axial alkynylation. Indeed, treatment of 20 with in situ generated BuAlCl2, followed by treatment of the crude product with 0.1M HCl in MeOH, gave the dialkynylated triol 22 in yields of 85 to 90%. Under similar conditions, the disilyl ether 21 reacted more slowly to 22 (75%). The slower reaction correlates with the assumed intramolecular interaction of the precoordinated Lewis acid with OC(6) in 20.
1,3‐Oxathiole and Thiirane Derivatives from the Reactions of Azibenzil and α‐diazo amides with thiocarbonyl compounds
Authors: Kägi Martin , Linden Anthony , Mlostoń Grzegorz , Heimgartner Heinz
Published: December 2004

The reactions of α‐diazo ketones 1a,b with 9H‐fluorene‐9‐thione (2f) in THF at room temperature yielded the symmetrical 1,3‐dithiolanes 7a,b, whereas 1b and 2,2,4,4‐tetramethylcyclobutane‐1,3‐dithione (2d) in THF at 60° led to a mixture of two stereoisomeric 1,3‐oxathiole derivatives cis‐ and trans‐9a (Scheme 2). With 2‐diazo‐1,2‐diphenylethanone (1c), thio ketones 2a–d as well as 1,3‐thiazole‐5(4H)‐thione 2g reacted to give 1,3‐oxathiole derivatives exclusively (Schemes 3 and 4). As the reactions with 1c were more sluggish than those with 1a,b, they were catalyzed either by the addition of LiClO4 or by Rh2(OAc)4. In the case of 2d in THF/LiClO4 at room temperature, a mixture of the monoadduct 4d and the stereoisomeric bis‐adducts cis‐ and trans‐9b was formed. Monoadduct 4d could be transformed to cis‐ and trans‐9b by treatment with 1c in the presence of Rh2(OAc)4 (Scheme 4). Xanthione (2e) and 1c in THF at room temperature reacted only when catalyzed with Rh2(OAc)4, and, in contrast to the previous reactions, the benzoyl‐substituted thiirane derivative 5a was the sole product (Scheme 4). Both types of reaction were observed with α‐diazo amides 1d,e (Schemes 5–7). It is worth mentioning that formation of 1,3‐oxathiole or thiirane is not only dependent on the type of the carbonyl compound 2 but also on the α‐diazo amide. In the case of 1d and thioxocyclobutanone 2c in THF at room temperature, the primary cycloadduct 12 was the main product. Heating the mixture to 60°, 1,3‐oxathiole 10d as well as the spirocyclic thiirane‐carboxamide 11b were formed. Thiirane‐carboxamides 11d–g were desulfurized with (Me2N)3P in THF at 60°, yielding the corresponding acrylamide derivatives (Scheme 7). All reactions are rationalized by a mechanism via initial formation of acyl‐substituted thiocarbonyl ylides which undergo either a 1,5‐dipolar electrocyclization to give 1,3‐oxathiole derivatives or a 1,3‐dipolar electrocyclization to yield thiiranes. Only in the case of the most reactive 9H‐fluorene‐9‐thione (2f) is the thiocarbonyl ylide trapped by a second molecule of 2f to give 1,3‐dithiolane derivatives by a 1,3‐dipolar cycloaddition.
The Photoisomerization Behavior of the (4‐Hydroxycinnamoyl)‐spermidines
Authors: Hu Wenquing , Werner Christa , Hesse Manfred
Published: December 2004

The photoisomerization behavior of three mono[(E)‐3‐(4‐hydroxyphenyl)prop‐2‐enoyl]spermidines, 1, 2, and 3, and three bis[(E)‐3‐(4‐hydroxyphenyl)prop‐2‐enoyl]spermidines, 4, 5, and 6, are investigated. The synthetic product (E)‐1 could be almost quantitatively (> 96%) converted into its isomer (Z)‐1 under UV light irradiation. In the cases of (E)‐2 and (E)‐3, a mixture of (E)/(Z) ca. 1:2 was obtained, when the same conditions were applied. The comparison of their UV spectra provides the possible explanation for these different behaviors. Furthermore, it was noticed that the (Z) → (E) isomerization of the CC bond took place during the purification by reverse‐phase high‐performance liquid chromatography (RP‐HPLC), and the (E)/(Z)‐mixture is thus inseparable. The same feature could be observed during the isolation of the (Z,Z)‐N,N′‐bis[3‐(4‐hydroxyphenyl)prop‐2‐enoyl]‐spermidines, (Z,Z)‐4, (Z,Z)‐5, and (Z,Z)‐6. Nevertheless, the fractions of (Z,Z)‐5 and (Z,Z)‐6 were in almost pure state collected, and their 1‐NMR spectra are presented.
N,Se‐Acetals: Preparation and use in diastereoselective radical reactions
Authors: Stojanovic Aleksandar , Renaud Philippe
Published: December 2004

A new facile synthesis of N,S‐ and N,Se‐acetals starting from aldehydes and primary amines is presented (Schemes 3–5). These acetals are used as precursors for stereoselective radical deuteration and allylation reactions (Schemes 6 and 7, Tables 1 and 2). The stereochemical outcome of the reactions depends on the radical trap and the substituents at the N‐atom. Deuterations give always anti products with moderate to high selectivities. The allylation reactions give either syn or anti products with low to moderate selectivities. The observed stereoselectivities can be explained with a model based on minimization of A1,3 strain and are controlled by steric and stereoelectronic effects.
Etudes sur les matières végétales volatiles. XXXIV. Sur la composition de l'huile essentielle de lavandin
Authors: Naves Y. R.
Published: December 2004

La présence dans l'essence de lavandin de d‐camphre, de d‐bornéol et de d‐camphène, annoncée dès 1941, est confirmée ici. Aux constituants signalés de divers cǒtés, il convient d'adjoindre le l‐α‐terpinéol, le l‐lavandulol, le nérol, l'alcool l‐périllique, décelés dans l'essence saponifiée, le l‐α‐pinène, le l‐camphène, le l‐limonène et le dipentène.
Beiträge zur Kenntnis von Oxy‐ und Hydrocellulose III. Die quantitative Bestimmung der Carbonylgruppen in Hydrocellulosen
Authors: Geiger Ernst , Wissler Alfred
Published: December 2004

1. Durch Kondensation von primären Aminen, Hydrazinen und Hydraziden mit den Aldehydgruppen in Halbactalbindung der Hydrocellulose lassen sich basische oder saure Gruppen in die Molekel einführen. Diese geben durch Ionenaustausch mit Farbstoffionen Salze, aus denen der Farbstoff leicht wieder abspaltbar ist und quantitativ bestimmt werden kann. Einer Aldehydgruppe entspricht ein Farbstoffion.
Beitrag zur Oxydbestimmung in Reinaluminium
Authors: Boner J. E.
Published: December 2004

Einleitend werden die bisher am meisten ausgeübten Verfahren zur Bestimmung des Oxydgehaltes in Rein‐Aluminium kritisch betrachtet und die damit erhaltenen Ergebnisse erwähnt. Anschliessend wird ein neues Verfahren beschrieben und einige Ergebnisse von allgemeinem Interesse mitgeteilt.
On the rapid computation of matrix elements
Authors: Prosser Franklin , Hagstrom Stanley
Published: December 2004

A method is presented for evaluating the overlap contribution to matrix elements over Slater determinantal wave functions formed from products of nonorthogonal spin orbitals. The method utilizes the overlap cofactor formulation for matrix elements. Prescriptions are given for rapid computation of the necessary cofactors. The method is particularly well suited to the evaluation of integrals over one‐, two‐, and three‐electron operators, such as are encountered in conventional configuration interaction calculations, density matrix evaluations, calculations using functions of interelectronic coordinates, etc.
Eigenspace manipulation in SCF theory
Authors: Arnau Catalina , Carbó Ramón , Huzinaga Sigeru
Published: December 2004

The procedure proposed by Silverstone and others to modify virtual levels in SCF theory is extended as a technique to be used in any type of generalized secular equations. Some useful results are obtained.
Exact calculation of exchange polarization energy for H ion
Authors: Chałasiński G. , Jeziorski B.
Published: December 2004

The exchange polarization energy and higher‐order exchange corrections arising in the second order of the Murrell‐Shaw and Musher‐Amos (MS‐MA) theory are evaluated analytically for the hydrogen molecule ion. At large internuclear distances the second‐order exchange energy predicted by MS‐MA theory behaves like \documentclass{article}\pagestyle{empty}\begin{document}$- \frac{1}{{18}}Re^{ - R}$\end{document}. It represents only 80% of the difference between the exact result of Holstein and the asymptotic value of the first‐order exchange energy. The same result holds for the case of Hirschfelder‐van der Avoird (HAV) and Hirschfelder‐Silbey (HS) theories.
The electronic structure of the excited states for B, C+, and C arising from the configuration 1s2 2s 2pn—the effect of removal of the “equivalence” restriction
Authors: Horino Yasuyo , Tatewaki Hiroshi
Published: December 2004

In order to test the effect of a removal of an “equivalence” restriction, some excited states of B, C+ and C arising from the configuration 1s22s2pn (n = 2, 3) are calculated by the use of a one‐diffuse‐electron model with the optimal spin coupling (DO), in which the freedom of the spin coupling is fully used. The configuration employed is 1s22s2pn–12p′ (n = 2, 3).

The DO method gives a good agreement with the term energies especially for boron (4P → 2P) and carbon (5S° → 3S°). A diffuse 3p natural orbital with a large occupation number is found for boron 2P and carbon 3S° by DO. This result is confirmed by configuration interaction calculations.

Using the same configuration as above, we also examine a one‐diffuse‐electron model with a fixed spin coupling for boron. This method almost reproduces the results of restricted Hartree–Fock and the effect of a removal of an “equivalence” restriction is not found.

The importance of utilizing the freedom of the spin coupling in a one‐diffuse‐electron model is strongly indicated in this article.
Nonrigid molecule effects in molecules with linear or nongeometrically equivalent equilibrium configurations
Authors: Dalton Bryan J. , Nicholson Philip D.
Published: December 2004

A theoretical study is made of the states of nonrigid molecules, extending earlier work to apply Longuet–Higgins' symmetry group of feasible permutation/inversions in two previously untreated cases. The first involves nonrigid molecule processes between different stereoisomers, that is between molecular equilibrium configurations of different geometrical shapes. The second takes into account nonrigid molecule processes in linear molecules. The theory is applied to the specific case of nonrigid molecule effects in the butyl ion C4H (case i), and the form of the nonrigid molecule energy levels and spectra are determined. The theory is also applied to determine the nonrigid molecule energy levels in linear H2F2 (case ii).
Calculated anisotropies in the fermi surface of alkali metals
Authors: Kennard E. B. , Waber J. T.
Published: December 2004

The densities of states and Fermi energies were accurately calculated from E(k) data obtained by the self‐consistent‐band Augmented Plane Wave (APW) method, using a quadratic energy expansion. The reliability of the Monte Carlo integration was investigated. It was sufficiently good to determine the anisotropy of the Fermi surface of lithium, sodium, and potassium.
Best optimized one‐electron wave‐functions. III. Direct examination of optimization effectiveness
Authors: Jakubowski P.
Published: December 2004

The effectiveness of the recently developed method for optimization of one‐electron wave‐functions is directly examined by means of a simple procedure. By means of the same procedure the dependence of electron correlation on the nuclear charge and on the number of electrons is also investigated.
Generalized spherical functions in the theory of many‐electron atoms
Authors: Rudzikas Z. B. , Kaniauskas J. M.
Published: December 2004

A new method for finding non‐relativistic and relativistic wave‐functions of an electron moving in the field of a nuclear charge in the jj coupling scheme is proposed. It is based on the usage of generalized spherical functions. The mathematical apparatus necessary to find the expressions for matrix elements of the non‐relativistic and relativistic energy or electron transition operators is developed. The formulas obtained for these matrix elements are more convenient than those usually used in jj coupling scheme; only their radial integrals and some phase multipliers depend on orbital quantum numbers.
Antineoplastic activity of honey in an experimental bladder cancer implantation model: In vivo and in vitro studies
Authors: SWELLAM TAREK , MIYANAGA NAOTO , ONOZAWA MIZUKI , HATTORI KAZUNORI , KAWAI KOJI , SHIMAZUI TORU , AKAZA HIDEYUKI
Published: December 2004

Objectives: The antitumor effect of bee honey against bladder cancer was examined in vitro and in vivo. Methods: Three human bladder cancer cell lines (T24, 253J and RT4) and one murine bladder cancer cell line (MBT‐2) were used in these experiments. In an in vitro study, the antitumor activity was assessed by 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyl tetrazolium bromide (MTT) assay, TdT‐mediated dUTP‐biotin nick end labeling (TUNEL) assay, 5‐Bromodeoxyuridine (BrdU) labeling index and flowcytometry (FCM). In the in vivo study, cancer cells were implanted subcutaneously in the abdomens of mice, and the effects were assessed by the tumor growth.

Results: In vitro studies revealed significant inhibition of the proliferation of T24 and MBT‐2 cell lines by 1–25% honey and of RT4 and 253J cell lines by 6–25% honey. BrdU labeling index was significantly lower. FCM showed lower S‐phase fraction, as well as absence of aneuploidy compared with control cells. In the in vivo studies, intralesional injection of 6 and 12% honey as well as oral ingestion of honey significantly inhibited tumor growth.

Conclusion: Bee honey is an effective agent for inhibiting the growth of T24, RT4, 253J and MBT‐2 bladder cancer cell lines in vitro. It is also effective when administered intralesionally or orally in the MBT‐2 bladder cancer implantation models. Our results are promising, and further research is needed to clarify the mechanisms of the antitumor activity of honey.