bluuebunny/crossref_metadata_2025_split huggingface dataset:
Temperature and Concentration Dependent Circular Dichroism of Mono‐ and Di‐cis Isomers of (3S,3′S)‐Astaxanthin Diacetate
Authors: Noack Klaus , Thomson Andrew J. 
Published: December 2004

AbstractThe circular dichroism (CD.) spectra of all‐trans‐(3S, 3′S) astaxanthin diacetate and its 9‐cis, 13‐cis, 9,9′‐di‐cis, 9,13′‐di‐cis, and 9,13‐di‐cis isomers conform to the rules previously formulated for optically active carotenoids with a 4‐oxo‐β‐end ring containing an asymmetric C‐atom [1]. Thus the CD. bands of the all‐trans and the di‐cis isomers show the same signs whereas those of the mono‐cis isomers have opposite signs. The CD. spectra of all the astaxanthin diacetate isomers invert sign upon cooling to −180°. The CD. spectra of the 9‐mono‐cis and 9,9′‐di‐cis isomers and to a lesser extent also those of the 9, 13′‐di‐cis and 9, 13‐di‐cis isomers are concentration dependent at −180°, with the longest wavelength band giving at the higher concentration a bisignate CD. curve under the main absorption characteristic of aggregation. This phenomenon has been observed only in isomers with a 9‐cis linkage. It is suggested that steric hindrance prevents such aggregation taking place in the other isomers.
Enamines. II. A theoretical and photoelectron spectroscopic study of the molecular and electronic structures of aliphatic enamines
Authors: Müller Klaus , Previdoli Felix , Desilvestro Hans 
Published: December 2004

AbstractComparison of PE. spectroscopic data for four series of enamines (including azetidine and some aziridine derivatives) for studying the influence of amine‐ring size on electronic structure show the pyrrolidino group to exhibit the strongest amine/double bond coupling in sterically unconstrained enamines. However, the azetidino group accommodates best steric congestion due to dialkyl substitution at the β‐position of the enamine unit. Quantum‐chemical calculations of equilibrium structures and energy profiles for amine rotations in model enamines by the PRDDO SCF method agree satisfactorily with experimental results. Notable exceptions are pyrrolidine derivatives for which PRDDO overestimates the amount of N‐pyramidality.
Activated C,H‐Acids: N‐Alkyl‐9‐fluorenimines. Preliminary communication
Authors: Bradamante Silvia , Colombo Silvana , Pagani Giorgio A. , Roelens Stefano 
Published: December 2004

AbstractN‐Substituted 9‐fluorenimines 1 are easily prepared from primary amines or aminoesters and 9‐fluorenimine: their conjugate carbanions 2 are formed by the action of alkoxides and are reprotonated to 1 or to the tautomeric 9‐alkylidenamino‐fluorenes 3 depending upon substituents.
Synthesis of L‐α‐aminoadipyl‐L‐serinyl‐D‐valine, a naturally occuring tripeptide from the fermentation of Penicillium chrysogenum
Authors: Shields James E. , Campbell Charles S. , Scott Doyle K. , Miller Roger D. , Neuss Norbert 
Published: December 2004

AbstractA new tripeptide, L‐α‐aminoadipyl‐L‐seryl‐D‐valine has been synthesized by coupling the protected L‐seryl‐D‐valine dipeptide with an appropriately protected L‐α‐aminoadipic acid ester. The free tripeptide was obtained after treatment with liquid HF and purification by HPLC.
A Convergent Synthesis of (±)‐α‐ and β‐Himachalenes
Authors: Oppolzer Wolfgang , Snowden Roger L. 
Published: December 2004

Abstract(±)‐α and β‐Himachalene, 5 and 6, have been synthesized in a convergent manner from 3,3‐dimethylacrolein (9), the ester enolate 10 and the silyloxypentadienyllithium 7. The key steps are the regioselective γ‐addition of the dienal 13 to 7 and the intramolecular Diels‐Alder addition 15 → 16. Hydrogenolysis of the diethylphosphate group and functionalization at C (5) completed the synthesis of 5 and 6.
Crystallographic and Spectroscopic Evidence for an Intramolecular (OH … π)‐Interaction
Authors: Bernd Schweizer W. , Dunitz Jack D. , Pfund Rolland A. , Ramos Tombo Gerardo M. , Ganter Camille 
Published: December 2004

AbstractCrystallographic and spectroscopic evidence for an intramolecular (OH … π)‐interaction in anti9,10‐10endo‐hydroxy, 10exo‐butyltricyclo [4.2.1.12.5]deca‐3, 7‐dien‐9‐one (1) is presented.
Nafion‐TMS‐ and TMS‐Trifluoroacetate‐Induced Rearrangements of Cyclopropyl Ketones ‐ A procedure for the regioselective conversion of semibullvalenes to barrelenes
Authors: Demuth Martin , Mikhail Gamal , George Manapurathu V. 
Published: December 2004

AbstractTrimethylsilyl trifluoroacetate (TMSTFA) and the polymer‐supported sulfonate Nafion‐TMS exhibit selective reaction modes in the opening of cyclopropyl ketones. The yields are generally high. Nafion‐TMS rearranges the tricyclooctanones 1a and 1b to the bicyclooctenones 4a and 4b (while TMSTFA gives ring‐opened adducts 6a,b) with high regioselectivity. Aro‐semibullvalenes (8a, 14, 17a,b) are efficiently rearranged to arobarrelenes (7a, 13, 20a,b) by both reagents. The latter rearrangements have also been achieved in mixtures of trifluoroacetic acid and tetramethylsilane (TMS), where the acid combines with an unidentified impurity of commercial TMS to form a strong electrophilic agent. The electrophile‐assisted rearrangement of the naphtho‐semibullvalenes 14a+b resulted in conversion to the naphthobarrelenes 13a+b with the opposite regioselectivity to that observed for the thermal equilibration at 220°.
1H‐ und 13C‐NMR.‐Spektroskopie der Nonadride
Authors: Nieminen Sirkku , Tamm Christoph 
Published: December 2004

1H‐ and 13C‐NMR. Spectroscopy of the NonadridesThe 1H‐ and 13C‐NMR. spectra of the nonadrides glaucanic acid (1), glauconic acid (2), heveadride (3), byssochlamic acid (4), scytalidin (5), rubratoxin A (6), and rubratoxin B (7) have been measured. Partial decoupling experiments permitted assignment of the majority of the signals.
The Effect of Solvent on Competing Hydroperoxide and Dioxetane Formation on Photo‐Sensitized Oxygenation of Olefins
Authors: Jefford Charles W. , Kohmoto Shigeo 
Published: December 2004

AbstractThe rates of the competitive photo‐sensitized oxygenation of 2‐isobutylideneadamantane (1) and 2‐propylidene‐adamantane (2) with 1, 1‐di‐t‐butyl‐2‐methoxyethane (3) in various solvents were determined. The rates for 1 and 2 were independent of solvent, whereas that for 3 varied markedly with solvent polarity. Compounds 1 and 2 gave only hydroperoxides while 3 gave dioxetane. These results are interpreted in terms of two competing processes involving little and much charge separation leading to hydroperoxide and dioxetane, respectively.
Synthese makrocyclischer Lactone durch Ringerweiterung. Vorläufige Mitteilung
Authors: Kostova Kalina , Lorenzi‐Riatsch Annalaura , Nakashita Yoshihiko , Hesse Manfred 
Published: December 2004

Synthesis of Macrocyclic Lactones by Ring Enlargement ReactionTreatment of 3‐(1‐nitro‐2‐oxocyclohexyl)propanal (1) prepared by Michael addition of 2‐nitrocyclohexanon and acrylaldehyde with methyltri (2‐propoxy)tita‐nium yielded a mixture of 2 and 3 which was converted into 6‐nitro‐9‐decanolide (4).
Synthese von (+)‐(5S, 6S)‐Azafrin‐methylester; absolute Konfiguration von Aeginetinsäure and von weiteren vicinalen Apocarotin‐diolen
Authors: Eschenmoser Walter , Uebelhart Peter , Eugster Conrad Hans 
Published: December 2004

Synthesis of (+)‐(5S, 6S)‐Azafrin Methyl Ester; Absolute Configuration of Aeginetic Acid and of Further Vicinal ApocarotenediolsWe describe the synthesis of a series of optically active vicinal apo‐β‐carotenediols. Thus, starting from (+)‐(5S, 6S)‐5,6‐dihydroxy‐5,6‐dihydro‐β‐ionone (2) we have prepared the (Z/E)‐isomeric (+)‐C15‐esters 7 and 8, the (+)‐retinoic derivatives 14, 15, 18, 19 and (+)‐methyl azafrinate (22), the enantiomer of the naturally occur‐ring compound (s. Scheme 1). Our synthesis also establishes the absolute configura‐tion of aeginetic acid (24), aeginetoside (25) and aeginetin (26), compounds isolated from the root parasite Aeginetia indica by Indian and Japanese workers (s. Scheme 2).The presented synthesis of optically active methyl azafrinate confirms our previous assignment [14] of the absolute configuration of azafrin (1a), which was based on degradative evidence.
Synthesis of Methyl 2‐Acetamido‐4,6‐di‐O‐acetyl‐3‐S‐acetyl‐2‐deoxy‐3‐thio‐α‐D‐mannopyranoside
Authors: Miljković Momčilo , Hagel Peter 
Published: December 2004

AbstractMethyl‐2‐acetamido‐4,6‐di‐O‐acetyl‐3‐S‐acetyl‐2‐deoxy‐3‐thio‐α‐D‐mannopy‐ranoside has been synthesized by conversion of methyl 2‐amino‐2‐deoxy‐4,6‐O‐benzylidene‐α‐D‐altropyranoside into the corresponding 3‐O‐methanesulfony1‐2‐N‐[(methylthio)thiocarbonyl]derivative followed by intramolecular displacement of the 3‐O‐methanesulfonyloxy group with the (methylthio)thiocarbamoyl group.
Variable temperature multinuclear NMR. Investigation of dimethylformamide exchange on the octakis (N,N‐dimethylformamide)‐thulium(III) ion
Authors: Pisaniello Dino L. , Merbach André E. 
Published: December 2004

AbstractThe rate of DMF exchange on [Tm (DMF)8]3+ has been determined by 1H‐ and 13C‐NMR. linebroadening techniques. 1H‐NMR. yields the following solvent exchange parameters; ΔH* = 33.2 (±0.5) kJ mol−1, ΔS* = 9.9 (±2.4) J K−1 mol−1and k (200 K) = 2.94 (±0.09)× 104 s−1, whilst results from 13C‐NMR. are similar. No evidence, by 35C1‐NMR., was found of contact ion‐pair formation when the perchlorate salts were used.
Structures cristallines et moléculaires des muses macrocycliques. II. La trans‐civettone et sa 2,4‐dinitrophénylhydrazone
Authors: Bernardinelli Gerald , Gerdil Raymond 
Published: December 2004

Crystal and Molecular Structure of Macrocyclic MUSKS. II. trans‐Civetone and its 2, 4‐DinitrophenylhydrazoneThe trans and cis isomers of civetone (C17H30O) crystallize in isomorphous systems and form plastic crystals (tetragonal, space group I41 a=9.95 (4), c = 32.79 (1) Å, Z = 8). Mixed crystals were prepared with cis‐civetone as second component. Accordingly the diffuse structural model obtained for the disordered phase of the cis‐isomer [1] is also regarded as representative of that of trans‐civetone.The crystal structure of trans‐civetone 2,4‐dinitrophenylhydrazone (DNPHTC; C23H34N4, Monoclinic, Space group P21/c, a=8.364(2), b=7.971(1), c=36.025(8) Å, β=91.44 (2)°) was solved by direct methods and refined to a final R of 0.09 (Rw = 0.021). The macrocycle adopts a sexangular conformation [23*434*44*], and its mean plane is approximatively perpendicular to that of the aromatic substituent. Empirical force field calculations have shown that the DNPH substituent has very little influence on the macrocycle conformation. The intermolecular interactions take place essentially between groups of the same type: macrocycle…macrocycle and DNPH…DNPH.
Formation and dissociation mechanism of amide complexes. V. Interconversion of dimeric and monomeric Cu2+‐complexes with 1,8‐diamino‐3,6‐diaza‐2,7‐octanedione: Comparison between the reactivity of terminal and internal amide groups
Authors: Zuberbühler Andreas D. , Kaden Thomas A. 
Published: December 2004

AbstractThe protonation and deprotonation rates of the coordinated amide groups in the Cu2+‐complexes of 1,8‐diamino‐3,6‐diaza‐2,7‐octanedione (DED = L) have been studied by stopped‐flow techniques. Starting at low pH from Cu2+ and DED the dimeric Cu2L24+‐complex, fully formed within the mixing time of the stopped‐flow instrument, reacts in two consecutive steps to yield the final product CuLH−2. The rate constants of the forward and backward reactions have been determined and are given in Table 1. The intermediate was identified as Cu2L2H−22+ by measuring its VIS.‐absorption spectrum.The rate constants for the interconversion of the amide groups from the O‐ to the N‐coordinated form in the Cu2+‐complexes of DED, 2,10‐dioxo‐1, 4, 8, 11 tetraazaundecane (DANA) and triglycine (TRIGLY) are compared with each other. It is shown that these rate constants are similar, no matter whether the amide group is terminal or internal as long as the rotation is easily possible as is the case in the dimeric species Cu2L24+ and Cu2L2H−22+. However, for CuLH−2 the inter‐conversion only takes place after opening of one of the chelate rings in a rapid protonation preequilibrium.
Herstellung der 1H‐Indazole durch Photolyse von 2‐Aminophenylketon‐O‐(äthoxycarbonyl)oximen und von 3,1,4‐Benzoxadiazepin‐2 (1H)‐onen
Authors: Pfoertner Karl‐Heinz , Foricher Joseph 
Published: December 2004

1H‐Indazoles Obtained by Photolysis of 2‐Aminophenylketon‐O‐(ethoxycarbonyl)oximes and of 3, 1, 4‐Benzoxadiazepine‐2(1 H)‐onesIrradiation of (E)‐ and (Z)‐O‐(ethoxycarbonyl)oximes 1 of 2‐aminophenyl ketones in solution with UV, and/or visible light gives 1 H‐indazole derivatives 2 in high yields (Scheme 1). For this reaction the amino group must be un‐ or mono substituted. With the N, N‐disubstituted (E)‐1d (Scheme 2) no 1 H‐indazole formation is observed, because the radicals formed by its photolysis react in an unspecific manner with each other and with the solvent. From the behaviour of (E)‐1d and from the lack of any E/Z‐isomerization of 1 we conclude that the photoreaction starts with a splitting of the N, O‐bond in two separate radicals, whereas the radical pair produced by the also studied photolysis of 3,1,4‐benzoxadiazepine‐2(1 H)‐one derivatives 3 is fixed in the parent molecule, and therefore tends to recombine.This makes a prolonged irradiation necessary to convert the benzoxadiazepinones 3 into the 1 H‐indazoles 2. The different reaction rates of the (E) and (Z)‐isomers of 1 (provided R4 = H) are understood by means of different intramolecular H‐bridges.
13C‐NMR. Spectra of Natural and Semi‐synthetic Cannabinoids
Authors: Binder Michael , Franke Ingo , Schmidt Burkhard , Dietrich Wolfgang 
Published: December 2004

AbstractThe 13C‐NMR. spectra of one natural and ten semi‐synthetic cannabinoids were analyzed in detail. Assignments of the signals are based on their chemical shifts, splitting patterns in 1H‐off‐resonance decoupling experiments and comparison with 13C‐NMR. data of related cannabinoids. With some compounds final assignments were made by selective 1H‐decoupling experiments and incremental calculations.
Technische Verfahren zur Synthese von Carotinoiden und verwandten Verbindungen aus 6‐Oxo‐isophoron. VII. Synthese von Rhodoxanthin und (3RS,3RS)‐Zeaxanthin aus der C15‐Ringkomponente
Authors: Widmer Erich , Zell Reinhard , Grass Hansjörg , Marbet Roman 
Published: December 2004

Technical Procedures for the Synthesis of Carotenoids and Related Compounds from 6‐Oxo‐isophorone. VII. Synthesis of Rhodoxanthin and (3RS,3RS)‐Zeaxanthin from the C15‐Ring Component1An efficient 7‐step synthesis of (3RS,3RS)‐zeaxanthin (3) in 20% overall yield starting from 6‐oxo‐isophorone (7) is described. Intermediates are 6,6′‐dihydro‐rhodoxanthin (4) and rhodoxanthin (1), which are now accessible in 4 and 5 steps, and 45 and 25% overall yield, respectively. Novel methods for the simultaneous removal of the hydroxy group and the partial reduction of the triple bond of a monoalkynylated 1,4‐dioxo‐2‐ene system have been developed.
Cyclometalation of arylazo compounds. Part 2Regioselectivity of the Cyclopalladation of Some Substituted 1‐Arylazonaphthalenes. 2nd Communication on Compounds with a Metal‐Arene σ‐Bond
Authors: Hugentobler Max , Klaus Alfred J. , Mettler Hanspeter , Rys Paul , Wehrle Gabi 
Published: December 2004

AbstractA variety of cyclopalladated 1‐arylazonaphthalenes is described, where ortho‐palladation occurs at C(2) in the naphthyl ring or at C(2′ or 6′) in the phenyl moiety. Two examples of Peri‐cyclopalladation at C(8) in the naphthyl ring are presented. The electronic and steric‐influences of substituents at either arene moiety on the relative basicities of the azo‐N‐atoms and the relative nucleophilicities of the potential palladation sites C(2), C(2′ or 6′), and C(8) are discussed qualitatively in order to rationalize the observed regioselectivity.
The Synthesis of Hetero‐Halogenated Derivatives of Phloroglucide Analogues[1]
Authors: Moshfegh Ali Akbar , Mazandarani Behnaz , Nahid Azarmidokht , Hakimelahi Gholam Hosein 
Published: December 2004

AbstractA short synthesis of the title compounds is reported. Most of the compounds prepared were found to be active against a number of pathogenic microorganisms in vitro.
Polar Effects. X. Polar Substituent Effects in the Solvolysis of 3‐Substituted 1‐Adamantyl Bromides and Toluenesulfonates
Authors: Grob Cyril A. , Schaub Bruno 
Published: December 2004

AbstractThe rate constants for 3‐substituted adamantyl p‐toluenesulfonates 3a‐3k in ethanol/water 80:20 correlate well with the respective inductive substituent constants σ. The reaction constant ρ for the toluenesulfonates 3 is 10% larger than for the corresponding bromides 2, indicating somewhat more charge separation in the activation of the toluenesulfonates. Evidence is presented that stabilization of the resultant 1‐adamantyl cations by induction involves graded 1,3‐bridging, which is favored when the substituent is an electrofugal group, and that stabilization by n‐electron donors involves C, C‐hyperconjugation. Rate ratios for the toluenesulfonates 3 and the bromides 1 exceed 103 and are almost independent of the 3‐substituents. The implications of this are discussed in the light of current hypotheses.
Rapid Silylation of a Glass Surface: Choice of Reagent and Effect of Experimental Parameters on Hydrophobicity
Authors: Deyhimi Farzad , Coles Jonathan A. 
Published: December 2004

AbstractThe silylation of the surface of sodium borosilicate glass was investigated under conditions that might be applied to the fabrication of ion‐selective microelectrodes of the liquid membrane type such as are used in physiology, Silylation was carried out for 15 min at different temperatures and with six different silanes. The hydrophobicity was measured and found to be greatest with reaction temperatures of 200–350°, the effectiveness of the different silylating agents being in the (increasing) order: trimethylchlorosilane, tributylchlorosilane, (dimethylamino)trimethylsilane, hexamethyldisilazane, dimethyldichlorosilane, bis(dimethylamino)dimethylsilane. The results give evidence of a catalytic effect of basic amine groups and show that the reactivity of the surface of freshly drawn glass is increased by acid leaching.
1‐p‐Menthene‐8‐thiol: A powerful flavor impact constituent of grapefruit juice (Citrus parodisi MACFAYDEN)
Authors: Demole Edouard , Enggist Paul , Ohloff Günther 
Published: December 2004

Abstract1‐p‐Menthene‐8‐thiol (B) is shown to be a potent character‐donating constituent of grapefruit juice, in which it occurs at the ppb‐level or below. A convenient synthesis is described for this terpene‐thiol, apparently the most powerful flavor compound ever found in nature.
Structural Factors Affecting the Basicity of ω‐Pyridylalkanols, ω‐Pyridylalkanamides and ω‐Pyridylalkylamines
Authors: Mayer Joachim M. , Testa Bernard 
Published: December 2004

AbstractThe present paper describes the preparation by conventional methods (when not available commercially) and the pKa‐determination of the α‐, β‐ and γ‐isomers of pyridylethanamide, 3‐pyridylpropanamide. 4‐pyridylbutanamide, 5‐pyridyl‐pentanamide, pyridylmethanol, 2‐pyridylethanol, 3‐pyridylpropanol, 4‐pyridyl‐butanol, 5‐pyridylpentanol, pyridylmethylamine, 2‐pyridylethylamine, 3‐pyridyl‐propylamine, 4‐pyridylbutylamine, and 5‐pyridylpentylamine. While a field effect accounts for many variations in pKa as a function of chain length, marked inductive effects are operative in some methyl and ethyl homologs. The pKa‐decreasing influence of an intramolecular H‐bond is also apparent in some lower homologs belonging to the α‐series.
A New Type of Photorearrangement of γ‐Hydroxy‐α, β, δ, ε‐dienone
Authors: Katsumura Shigeo , Isoe Sachihiko 
Published: December 2004

AbstractA new type of photorearrangement of the γ‐hydroxy‐α, β, δ, ε‐dienone, vomifoliol acetate (2) to the diketone 4 is described, and its facile rearrangement is compared with that of desoxyvomifoliol acetate (3).
Synthese einiger 1,2‐Dihalogen‐norbornane
Authors: Krebs Ernst‐Peter , Keese Reinhart 
Published: December 2004

Synthesis of some 1,2‐DihalogenonorbornanesThe synthesis of 1,2exo‐Dibromo‐norbornane as well as the preparation of the configurational isomers of 2‐bromo‐1‐iodo‐ and 2‐chloro‐1‐iodo‐norbornane are described.
Synthese und Hydrolyse von 6endo‐substituierten p‐Toluolsulfonsäure‐[2endo‐norbornyl]estern. Norbornanreihe, 9. Mitteilung
Authors: Grob Cyril A. , Günther Bettina , Hanreich Reinhard 
Published: December 2004

The Synthesis and Hydrolysis of 6endo‐Substituted 2endo‐Norbornyl p‐ToluenesulfonatesThe hydrolysis products of the p‐toluenesulfonates of several hitherto unknown 6endo‐substituted 2endo‐norbornanols have been determined.
Arylierungen von cyclischen Guanidin‐Analogen mit α‐halogenierten Anthrachinonen: neue Anthrapyrimidine
Authors: Adam Jean‐Marie , Winkler Tammo , Rihs Grety 
Published: December 2004

Arylation Reaction of Cyclic Guanidine‐Analogs with α‐Halo‐ anthraquinones: New Anthrapyrimidines2‐Amino‐benzimidazole gives on Ullmann‐reaction with α‐halo‐athraquinones such as 1‐amino‐4‐bromoanthraquinone‐2‐sulfonic acid (la) the new benzimidazo‐anthrapyrimidine 2a, whereas 3‐amino‐ triazole gives under the same conditions two products: the 1,2,4‐triazoloanthrapyrimidine 7 and l‐amino‐4‐(3‐amino‐1,2,4‐ triazolyl)anthraquinone‐2‐sulfonic acid (8). The new structures were elucidated by 1H‐ and 13C‐NMR. and X‐ray analysis.
Consecutive Application of the α‐Alkynone Cyclization: Total Synthesis of (±)‐Δ9(12)‐Capnellene
Authors: Huguet Joan , Karpf Martin , Dreiding André S. 
Published: December 2004

AbstractThe synthesis of the (±)‐form of the marine sesquiterpene (–)‐Δ9(12)‐capnellene (1) by double application of the a‐alkynone cyclization is described. Starting with 2, 2, 5‐trim ethylcyclopentanone (2), the elaboration of the tricyclo [6.3.0.02,6]undecane C‐skeleton of 1 proceeded through the a‐alkynone 3, which was cyclized thermally to the bicyclo [3.3.0]octenone 4. For the anellation of the third five‐membered ring, 4 was transformed into the a‐alkynone 5 and the latter cyclized thermally to a mixture of the angular triquinenone 6 and the linear triquinenone 7. The last steps in the synthesis of (±)‐Δ9(12)‐capnellene (1) were then accomplished from 7 by known methods.
Synthesis of Unbranched 4‐Alkylbenzaldehydes
Authors: Osman Maged A. 
Published: December 2004

AbstractThe preparation of unbranched 4‐alkylbenzaldehydes free of positional and branched‐chain isomers by different methods is described. A one‐step preparation of the aldehydes is reported which involves the ‐direct hydrogenation of a Friedel Craft's complex in the presence of Pd/C catalyst.
A Further Synthetic Approach to the Adamantane Isomer 2, 5‐Trimethylenenorbornane (Tricyclo [5.3.0.03,9]decane, 4‐Homotwistbrendane)
Authors: Känel Hans‐Ruedi , Ganter Camille 
Published: December 2004

AbstractA further synthetic approach to 2, 5‐trimethylenenorbornane (1; tricycle [5.3.0.03,9]decane, 4‐homotwistbrendane), a member of the «adamantaneland», is described starting from methyl 5‐oxo‐2endo‐norbornanecarboxylate (5). The required C2‐chain was introduced by a Wittig‐Horner reaction and the ring closure of the trimethylene bridge achieved by an acyloin condensation.
Effect of Doping and Solution Redox Relays on the Efficiency of Photocathodic Processes at the p‐InP/Water Interface
Authors: Geiger Thomas , Nottenberg Richard , Pélaprat Mary‐Lou , Grätzel Michael 
Published: December 2004

AbstractLight‐induced interfacial electron transfer from two p‐InP electrodes differing in the amount of majority carrier doping to a number of electron relays (R) dissolved in aqueous solution was investigated. The material with the lower carrier density (0.71 × 1018 cm−3) exhibited much better wavelength response and quantum yield for electron transfer than the electrode doped with 2.3 × 1018 cm−3 charge carriers. Using cobalt (III) sepulcrate, Co (sep)3+, as an electron relay a polychromatic light to electrical energy conversion efficiency of 18% was obtained. The potential of this relay for use in a regenerative photoelectrochemical cell is briefly discussed.