bluuebunny/crossref_metadata_2025_split huggingface dataset:
Enantiopure Indolizidones and Pyrrolizidones from Maleic Imide
Authors: Dockner Michael , Meyer Thorsten , Nemes Peter , Otten Martina G. , Winterfeldt Ekkehard 
Published: September 2010

AbstractThe alkylated maleic imide adducts of type 3 have been shown to undergo highly regioselective selectride reductions. As with these compounds regioselectivity in further transformations including a thermal retro process translates directly into enantioselectivity, various cyclisation techniques were applied. The advanced cycloadducts obtained led to the enantiopure alkaloid precursors 9, 17, 20 and 25 in very high yield.
Aluminiumchloride‐Induced Additions of Formaldehyde to Alkenes
Authors: Metzger JüRgen O. , Biermann Ursula 
Published: September 2010

AbstractThe addition of formaldehyde to alkenes induced by AlCl3 is a simple route to alkylsubstituted tetrahydropyrans. Additions of two equivalents of formaldehyde to 1‐alkenes and 1,2‐dialkylsubstituted alkenes give 3‐alkyl‐4‐chlorotetrahydropyrans and 3,5‐dialkyl‐4‐chlorotetrahydropyrans, respectively. The products are obtained as a mixture of diastereomers. 2,5‐dialkyl‐4‐chlorotetrahydropyrans are obtained in AlCl3‐induced additions of one equivalent of formaldehyde to homoallylic alcohols. Reductive dechlorination gives the corresponding 3‐, 3,5‐ and 2,5‐alkylsubstituted tetrahydropyrans, respectively.
Derivatives of Triphenylphloroglucinol
Authors: Gaudig Tanja , Siegfried Hünig  , Peters Karl , Schnering Hans‐Georg Von 
Published: September 2010

AbstractSince triphenylphloroglucinol (1) has been described with widely differing properties, the correct structure has been substantiated by X‐ray analysis. On oxidation of 1 the dimer 5 is formed irreversibly by coupling between two phenyl groups. All three OH groups in 1 were acylated by pivaloyl chloride/AlCl3 (→2). By methylation of 1 both the dimethoxy‐(3) and trimethoxy‐(4) derivatives are formed. On oxidation with K3[Fe(CN)6]/OH− phenol 3 yields the persistent radical 3rad, which was characterized by its ESR signal and isolated as the dimer 6. Hydroquinone reverts 6 back to 3.
Microbial Oxidation of Geranylacetone and Geranyloxycoumarin, Aurapten
Authors: Müller A. , Abraham W. R. , Kieslich K. 
Published: September 2010

AbstractGeranylacetone and geranyloxycoumarin (aurapten) were investigated with 14 selected microorganisms for ω‐hydroxylation and epoxydation of the subterminal double bond. Trichoderma koningii and Verticillium theobromae are in principal useable for both reactions of geranyacetone. Although the yields of these preferably intended reactions were low, while ω‐1‐, ω‐3‐, ω‐4‐hydroxylations partially combined with reductive side reactions take place, the results gave an insight in the different pathways of oxidations dependent on the microorganism used. In contrast aurapten is transformed in relatively high yield to the E‐ or/and Z‐configurated ω‐alcohols (auraptenols) and to the aurapten‐6,7‐epoxide. The exclusively useable microorganisms for the oxidation of aurapten selected from the 237 strains tested were Nocardia alba and Bacillus cereus, which both formed enantioselectively the naturally configurated epoxyaurapten R‐(+)‐[6′,7′‐epoxy‐3′,7′‐dimethyl‐2′ octenyl]‐7‐oxycoumarin in yields of 10.5% respectively 21% of excellent optical purity of 99%ee.
Total Synthesis of Periplanone‐B Via Intramolecular Diels‐Alder Reaction with Furan‐Diene and Allene‐Dienophile
Authors: Geyter Tom De , Cauwberghs Serge , De Clercq Pierre J. 
Published: September 2010

AbstractA synthetic route towards (±)‐periplanone‐B is described based on (i) an intramolecular Diels‐Alder reaction involving a furan‐diene and an allene‐dienophile, (ii) selective (C‐O)‐cleavage in the resulting adduct by lithium di‐tert‐butylbiphenyl radical anion; (iii) a Grob fragmentation leading to the ten‐membered ring, as key‐steps.
Dichloro(2,2‐Dimethylcyclopropyl)Methyl Phenyl Sulfone ‐ a Radical Probe for Detecting Single Electron Transfer Processes
Authors: Makosza Mieczyslaw , Kwast Andrzej 
Published: September 2010

AbstractThe title compound was synthesized and was shown to be a fast radical probe for studying single electron transfer processes in reactions of carbanions with polyhaloalkanes. It has a universal character ‐ being originally an electron acceptor, upon dehelogenation forms carbanion which is an electron ‐ donor radical probe.
The Reaction of Perfluorobutanesulfonyl Fluoride with Alcohols in the Presence of 4‐Dialkylaminopyridines
Authors: Bennua‐Skalmowski Bärbel , Krolikiewicz Konrad , Vorbrüggen Helmut 
Published: September 2010

AbstractPrimary hydroxy groups as in neopentyl alcohol 7 or neopentylglycol 18 react readily with perfluorobutanesulfonyl fluoride 1 in the presence of 2 equiv. of the nucleophilic 4‐dialkylaminopyridines 4 to afford high yields of the corresponding N‐alkyl‐4‐dialkylaminopyridinium perfluorobutanesulfonates (nonaflates). Secondary hydroxy groups give rise to a mixture of the corresponding olefins and monofluorides as well as of the corresponding N‐alkyl‐4‐dialkylaminopyridinium nonaflates.
Synthesis of Glycosidase‐Inhibiting Iminopolyols Via Isoxazolines1,2
Authors: Jäger Volker , Müller Rudolf , Leibold Thomas , Hein Matthias , Schwarz Marietta , Fengler Marion , Jaroskova Libuse , Pätzel Michael , Leroy Pierre‐Yves 
Published: September 2010

AbstractThe 1,3‐dipolar cycloaddition of allyl halides with chiral nitrile oxides, derived from glyceraldehyde derivatives, affords ca. 1:1‐mixtures of C5‐epimeric isoxazolines. The diastereomers can be separated on a preparative scale by MPLC; the configurations at C5 are established by chemical correlation/X‐ray analysis initially, and then routinely, based on consistent, large differences of respective specific rotations. – An unexpected finding, which turned out to be the key to efficient transformation of 5‐halomethyl‐isoxazolines into hydroxy‐pyrrolidines, is that highly stereoselective catalytic hydrogenations are feasible with proper combination of both 3‐ and 5‐side chain structures and the catalyst system. – This (C3 + Cn)‐approach is extended to include dihydroxy‐pyrrolidines, i. e. 1,4‐iminopolyols, and further 1,5‐iminopolyols and bicyclic 1,5,8‐iminopolyols. The substrates for the latter hydrogenation/cyclization are derived from optically active furoisoxazolines. – Some of the new iminopolyols show strong inhibition of glucosidases.
Phosphorus Substituted “CN2 ” Groups: Building Blocks in Heterocyclic Chemistry
Authors: Baceiredo Antoine , Réau Régis , Bertrand Guy 
Published: September 2010

AbstractThe synthesis and reactivity of diazomethylenephosphoranes 2, bis(phosphanyl)carbodiimide 5, and N‐phosphanyl nitrilimine 10 are presented. The synthesis of transient N‐phosphanyl isodiazirine 19 and its rearrangement into 1,3,2λ5‐diazaphosphete 20 are discussed.
Design and Synthetic Applications of New Heterometallacycles
Authors: Echavarren Antonio M. , Cárdenas Diego J. , Castaño Ana M. , Cuerva Juan M. , Mateo Cristina 
Published: September 2010

AbstractThe reaction of cyclic anhydrides with Ni(0) complexes lead to the formation of nickelacycles by oxidative addition followed by decarbonylation. The preparation of chiral nickelacycles from anhydrides derived from amino acids and their reactivity is described. The formation of new heteropalladacycles by C‐H activation or transmetallation reactions and their reactivity will be also discussed.
Palladium‐Catalyzed Aerobic Oxidation of Allylic Amines via Heterocyclic Intermediates
Authors: Hiemstra Henk , van Benthem Rolf A. T. M. 
Published: September 2010

AbstractThe efficient transformation of allylic amines into 2‐amino‐3‐alken‐1‐ols and 1,2‐diamino‐3‐alkenes is described. The key step is the functionalization of the π‐bond of the starting material via palladium(II)‐mediated attack by an oxygen or nitrogen nucleophile, followed by palladium hydride elimination. When this reaction is carried out in DMSO as the solvent, molecular oxygen serves as a clean and efficient oxidant (without the need of a co‐oxidant), thus making the process catalytic in palladium. By tethering the nucleophile to the nitrogen atom of the starting allylic amine, the intramolecular character of the key reaction ensures excellent regio‐ and stereoselectivity in several cases. The tether is readily removed by using an electrochemical oxidation and hydrolysis.
Highly Stereocontrolled Formal Total Synthesis of Hemibrevetoxin B
Authors: Yamamoto Yoshinori , Kadota Isao 
Published: September 2010

AbstractStereocontrolled synthesis of hemibrevetoxin B framework, 7,7,6,6‐tetracyclic ether skeleton, has been accomplished via the intramolecular allylic tin‐aldehyde (and ketone) condensation.
AIPO4 AS CATALYST IN ORGANIC REACTIONS. V. INFLUENCE OF THE CHEMICAL AND TEXTURAL PROPERTIES OF SOLID CATALYST IN THE ESTERIFICATION PROCESS
Authors: Fernández‐Sánchez C. , Gandasegui M. T. , Marinas J. M. , Sinisterra J. V. 
Published: September 2010

AbstractThe influence of the chemical and textural properties of several aluminium orthophosphates catalysts in the esterification of acetic acid with n‐amyl alcohol is studied. The surface area but not the number of acid site of the catalyst is the determinant property in the catalytic activity. The influence in the yield of the water present in the medium is analyzed.
LINEAR AND ANGULAR ANALOGUES OF 5‐METHOXYFUROCOUMARIN
Authors: Antonello Cipriano , Zagotto Giuseppe , Miranda RocÍO , Uriarte Eugenio 
Published: September 2010

AbstractFormation of the furan ring of 5‐methoxyfurocoumarins by cyclization of the corresponding keto‐ether gave angular and linear isomers in ratios varying between 3:1 and 3:2 in favour of the angular isomer. Starting 7‐hydroxy‐5‐methoxy‐4‐methylcoumarin (5) and its 5‐hydroxy‐7‐methoxy isomer (6) were obtained in approximately 1:1 ratio by Pechman reaction of 5‐methoxyresorcinol (4) and ethyl acetoacetate. All products were isolated by flash chromatography and characterized by NOE spectroscopy.
SYNTHESIS, CHARACTERIZATION AND ELECTRIC PROPERTIES OF TERNARY LANTHANIDE(III) COMPLEXES WITH M‐HYDROXYBENZOATE AND THE BIDENTATE LIGAND (BIPY OR PHEN)
Authors: Zhao Xiueyuan , Wang Liufang , Wang Shuangxi , Wu Jigui , He Fengying , Xu Jiwu 
Published: September 2010

AbstractThe ternary lanthanide (III) complexes with m — hydroxybenzoate and the bidentate ligand (the ligand = bipy. phen) having the formulas Ln(bipy)L3. nH2O and Ln(phen) L3(where L = m‐hydroxybenzoate, Ln = La, Gd, Dy, Y) have been prepared and characterized by elemental analyses, IR and electronic spectra, molar conductance and thermal analyses. The electrically conductive properties for these complexes have also been examined. It has been found that the bipy complexes have semiconductor properties, whereas the phen complexes don't.
FACILE SYNTHESIS OF 2‐SUBSTITUTE BENZOTHIAZOLES VIA KETENES
Authors: Abayeh O. J. , Olagbemiro T. O. , Agho M. O. , Amupitan J. O. 
Published: September 2010

AbstractThe generation of phenyl‐, diphenyl‐, phenoxy‐, and chloroketenes, by the dehydrochlorination of the corresponding acid chlorides with triethylamine, in the presence of 2‐aminothiophenol 1 gave 2‐substituted benzothiazoles 3 in good yields.
ORTHOAMIDES, XLVIII: REACTIONS OF AN AZAVINYLOGUE AMIALESTER [2‐AZA‐1,3‐BIS(DIMETHYLAMINO)‐3‐METHOXY‐1‐PROPEN] WITH CH2‐ACIDIC COMPOUNDS
Authors: Kantlehner Willi , Hauber Michael 
Published: September 2010

AbstractCondensation reactions of azavinylogue orthoamides 5a and 6a with CH2‐acidic compounds are described. Reaction products are formylated ‐ or azavinylogue formylated compounds 8 and 9 resp. The condensation reactions of 5a can be enhanced by addition of trimethyl borate. Under these conditions the formylations reaction‐leading to compounds of type 8 ‐ is preferred.
SYNTHETIC MODIFICATIONS OF ANTISENSE OLIGONUCLEOTIDES: NOVEL BACKBONE REPLACEMENTS WITH IMPROVED PROPERTIES
Authors: Mesmaeker Alain De , Waldner Adrian , Fritsch ValÉRie , Lebreton Jacques , Wolf Romain M. 
Published: September 2010

AbstractEleven different types of backbone replacements have been investigated. The thermodynamic stability of the duplexes formed between these modified oligonucleotides and their RNA complements are summarized. Among these backbone replacements, we identified two amide derivatives which display improved properties for their application to the antisense strategy. A summary of our molecular modeling study on some of these modifications is also presented.
CYCLOADDITION DIPOLAIRE‐1,3 DES N‐ARYL‐C‐ETHOXYCARBONYLNITRILIMINES SUR LA 1‐METHYL‐5,7‐DIPHENYL‐1,4‐DIAZEPINE ET SUR LA 2‐METHYL‐4‐PHENYL‐1,5‐BENZODIAZEPINE
Authors: Baouid A. , Benharref A. , Hasnaoui A. , Lavergne J. P. 
Published: September 2010

AbstractThe reaction of N‐aryl‐C‐ethoxycarbonyl nitrilimines with the title compounds leads to [1,2,4] triazolo [1,4] diazepine, [1,2,4] triazolo [1,5] benzodiazepine and bis [1,2,4] triazolo [1,5] benzodiazepine. The 1,3‐dipolar cycloaddition is completely peri and regioselective.
ADDITION DE 2‐ALCOXYCARBONYL AZIRIDINES YLURES D'AZOMETHINE POTENTIELS A QUELQUES VINYLISOCYANATES
Authors: Mamoun O. , Benhaoua H. 
Published: September 2010

AbstractThe addition of azomethine ylides generated from the thermal ring opening of the corresponding 2‐alcoxycarbonylaziridines on various vinylisocyanates occured exclusively on the CN double bond. Only one orientation of the addition was observed in accordance with previous work in this area. The structure of the epimeric imidazolidones obtained was established by spectroscopic methods (RMN1H, 13C and mass spectrometry).
OLD AND NEW APPROXIMATE FORMULAE FOR ELEMENTARY PH CALCULATIONS, AND THEIR LIMITS OF APPLICABILITY
Authors: Cardinali Mario E. , Giomini Claudio , Marrosu Giancarlo 
Published: September 2010

AbstractThe paper discusses the limits of applicability of the most common approximate formulae employed for calculating the [H3O+] value of aqueous solutions containing a weak electrolyte whose acid‐base behaviour is completely described by a single ionization process. These limits are so fixed as to avoid that absurd results are obtained. In addition, a new simple formula is proposed, that overcomes some drawbacks of the traditional formulae, and an unknown, singular feature of a well‐known formula is pointed out.
UNSUPPORTED NiMo CATALYSTS. INFLUENCE OF THE SULFINDING TEMPERATURE AND EVOLUTION OF THE UNSUPPORTED NiMoS PHASE DURING REACTION
Authors: Karroua M. , Matralis H. , Grange P. , Delmon B. 
Published: September 2010

AbstractA series of unsupported NiMo catalysts, containing 30% Ni atoms, were prepared by the homogeneous sulfide precipitation method (HSP) and sulfided at different temperatures in the range 673‐1073 K. XPS, XRD, microelectrophoresis and BET surface area measurements were used to characterize the samples. The catalytic activity of the various catalysts for the hydrodesulfurization of thiophene and the hydrogenation of cyclohexene in a mixture containing both compounds was measured in mild conditions (573 K, 3 MPa). Both the evolution of the “NiMoS phase” during catalytic reaction and the influence of the sulfidation temperature on the properties of the unsupported NiMo catalysts were investigated.The sample sulfided at 673 K gave all the characteristic signals of the “NiMoS phase”. As the sulfidation temperature increases, larger amounts of nickel segregate from “NiMoS phase” to form nickel sulfide. The “NiMoS phase” was found unstable under reaction conditions. The maximum catalytic activity for both HDS and HYD reactions was obtained when both “NiMoS phase” and bulk Ni3S2were present in the catalyst. It thus appears as a precursor of a very active mixture of phases rather than of the stable catalyst itself. These results are discussed in relation to some models attempting to explain the synergy in the NiMo catalysts. They are compatible with the remote control mechanism.
PREPARATION DE PYRROLIDINES N‐METHYLEES A PARTIR DE PYRROL‐1‐INES
Authors: Perrocheau J. , Danion D. , Carrié R. 
Published: September 2010

AbstractPyrrol‐1‐ines obtained by 1,3‐dipolar cycloaddition of nitriles ylides to gem‐disubstituted by withdrawing groups olefins are converted to 1‐pyrrolinium salts by methylfluorosulfonate. Nucleophilic addition to these iminium salts affords 1 ‐pyrrolidines in good yields. Attempts to synthesize aziridines by thermolysis or flash thermolysis of these pyrrolidines through cycloreversion was unsuccessful. However the fragmentation under electronic impact of the pyrrolidines obtained from imidoyl chloride 5A and 5B allowed us to establish the 5 position of the paranitrophenyl group in the pyrrol‐1‐ine cycloadducts.
A CONVENIENT ACCES TO 1,7‐DIFUNCTIONAL NAPHTHALENES: THE SYNTHESIS OF THE 1,7‐DICARBALDEHYDE 7‐MONODIMETHYLACETAL
Authors: Jouanno Chantal , Floc'H Yves Le , Grée René 
Published: September 2010

AbstractAn easily accessible route to the 1,7‐dicarbaldehyde 7‐monodimethylacetal 7 is described. It proceeds in a six step sequence from the known 7‐methyl‐l‐tetralone.
REACTION DES METHYLENE γ‐BUTYROLACTONES AVEC LES ARYLNITRILOXYDES. EVOLUTION INATTENDUE DU BISADDUIT ISSU DE LA 5‐METHYLENE(5H)FURAN‐2‐ONE
Authors: Fihi Rachid , Ciamala Kabula , Vebrel Joël , Rodier Noël 
Published: September 2010

AbstractIn explorations of synthesis and chemistry of spiroheterocycles, we found that reaction of aromatic nitrile oxydes with methylene γ‐butyrolactones (at room temperature) produced spiroheterocycles 4, 5 and 6. When cycloadditions were carried out in refluxing toluene, the methylene(5H)furan‐2‐one 3 gives a totally unexpected product 8.
STUDIES ON MACROCYCLIC DITERPENOIDS (XV) ‐ TOTAL SYNTHESIS OF (R)‐(‐)‐CEMRENE‐A
Authors: Yue Xiangjun , Li Yulin 
Published: September 2010

AbstractThe total synthesis of (R)‐(‐)‐cembrene‐A was described in ∼29% overall yield from E‐geranyl acetone and (R)‐(+)‐limonene through ten steps by using the modified Wittig reaction and titanium‐induced intramolecular carbonyl coupling as key steps.
FIRST TOTAL SYNTHESIS OF (‐)‐DEHYDROCARISSONE
Authors: Liu Lijun , Xiong Zhaoming , Nan Fajun , Li Tongshuang , Li Yulin 
Published: September 2010

AbstractThe first synthesis of (‐)‐ dehydrocarissone (1) has been described, employing the dehydrogenation with DDQ as the key step.
CRYSTAL STUDIES OF MUSK COMPOUNDS. XIV. A REDETERMINATION OF THE MOLECULAR STRUCTURES OF THREE NITROBENZENE MUSKS : DISCUSSION OF THE GEOMETRY OF A TERT‐BUTYL GROUP ATTACHED TO A BENZENE RING AND EMBEDDED BY TWO NITRO GROUPS
Authors: De Ridder Dirk J. A. , Schenk Henk 
Published: September 2010

AbstractThe crystal structures of Musk Xylene (1, 1‐tert‐butyl‐3,5‐dimethyl‐2,4,6‐trinitrobenzene), Musk Ketone (2, 4‐acetyl‐1‐tert‐butyl‐3,5‐dimethyl‐2,6‐dinitrobenzene) and Musk Tibetene (3, 1‐tert‐butyl‐3,4,5‐trimethyl‐2,6‐dinitrobenzene) have been redetermined (1 and 3 at reduced temperature) and the accuracy is compared. Compound 2 has four molecules in the asymmetric unit but no additional crystallographic symmetry could be detected.The tert‐butyl group in the molecules is adjacent to two nitro groups at the neighbouring sites and a systematic pattern is observed in its bond distances and angles. The influence of a tert‐butyl group on the endocyclic angles of a phenyl ring is discussed.
THERMOLYSIS OF N‐BENZYL DERIVATIVES OF 2‐AMINOPYRIDINES. A CHARGE SENSITIVITY (CS) AND MNDO STUDY OF ELECTROPHILIC SUBSTITUTION OF 2‐AMINOPYRIDINES
Authors: Kowalski Piotr 
Published: September 2010

AbstractThe thermolysis reaction of N‐mono (1, 2) and N‐disubstituted (3, 4) benzyl derivatives of 2‐aminopyridines were carried out at 250°C in order to verify the scheme of the reaction of 2‐aminopyridines with electrophiles. N‐Annular benzyl substituent in 1 and 3 rearrange into N‐exocyclic (2 and 4, respectively) both in mono and disubstituted series. C‐Benzyl derivative formation (2‐benzylamino‐5‐benzylpyridine (10) hydrochloride) takes place as the result of rearrangement of N‐disubstituted benzyl derivatives, 3 and 4 hydrochlorides, only. N‐Mono benzyl derivatives, 1 and 2 hydrochlorides, did not rearrange to C‐benzyl compounds. Hard‐soft parameters of atoms‐in‐molecule (AIM) in 2‐aminopyridine systems as well as the nature of the electrophilic agent influence different reactivity of the 2‐aminopyridine systems. The N‐annular derivative formation (B) is controlled mainly by an electrostatic component (ES) i.e. interaction hard‐hard, while C‐substitution, formation of D, mainly by charge transfer (CT) component i.e. interaction soft‐soft. Increasing of effectively of N‐exocyclic (C) and C‐substituted (D) derivative formation is influenced by decreasing of the hardnesses of an electrophilic agent and hardnesses of AIM in 2‐aminopyridine system.
NICKEL(II) AND COPPER(II) COMPLEXES OF 5‐ARYL‐1‐PHENYLPENT‐1‐YNE‐3,5‐DIONES
Authors: Hassaan Aly M. A. , Marei M. G. 
Published: September 2010

AbstractNi(II) and Cu(II) complexes of 5‐aryl‐1‐phenylpent‐1‐yne‐3,5‐diones have been synthesized and characterized by elementary analysis, infrared and electronic spectra, molar conductivity and magnetic measurements. Octahedral and distorted octahedral configurations are suggested for Ni(II) and Cu(II) complexes, respectively.
VANADIUM‐TITANIUM OXIDE CATALYSTS. INFLUENCE OF THE PREPARATION METHOD ON THE o‐XYLENE SELECTIVE OXIDATION
Authors: Georgiadou I. , Slavov S. , Papadopoulou CH. , Matralis H. K. , Kordulis CH. 
Published: September 2010

AbstractVanadium oxide supported on titania catalysts prepared by the “Equilibrium Deposition followed by Filtration” method (EDF) and the conventional Wet‐impregnation method (WI) were extensively characterized by the joint use of various physicochemical techniques (BET, XRD, FT‐IR, DRS, XPS, AEM, TPR, and TPD of NH3) and were tested for the partial gas‐phase oxidation of o‐xylene. It was found that the EDF method leads to more selective monolayer catalysts. The increased selectivity has been attributed to the reduction of the surface acidity, to the enhancement of the VV/ VIV ratio and to the redox properties induced in this catalyst by the above preparation method
CONVERSATION DU GAZ DE SYNTHESE EN HYDROCARBURES LIQUIDES:INFLUENCE DU SUPPORT ET DES PROMOTEURS (La, Ce ET Mn) SUR LES CATALYSEURS AU COBALTS
Authors: Barrauit JoËL , Biwole Nazaire 
Published: September 2010

AbstractThe hydrocondensation of carbon monoxide into liquid hydrocarbons was studied in presence of cobalt catalysts modified with cerium, lanthanum or manganese salts and supported on carbon. After an oxidative activation of the support, the addition of cerium to cobalt increases the (C5‐C11) fraction while the addition of manganese increases the (C12‐C25) fraction.
GC/MS SEPARATION AN IDENTIFICATION OF THE C5H10 ISOMERS. APPLICATION TO THE Hg 6(3P1) PHOTOSENSITIZED REACTIONS OF cis‐2‐PENTENE, 1‐PENTENE AND trans‐1,2‐DIMEHYLCYCLOPROPANE
Authors: De Maré George R. , Termonia Marc 
Published: September 2010

AbstractThe analysis (separation and identification) of eleven C5H10 isomers is performed using coupled GC/MS with a 70 m glass capillary column containing a 2.5 μm thick film of PS225 as stationary phase. Cryogenic CO2 cooling improves the separations. The total analysis time is less than 12 minutes.Some mechanistic details on the Hg 6(3P1) (hereafter denoted by Hg*) photosensitization of the title compounds are elucidated. Thus the Hg* photosensitization of cis‐2‐pentene at 20 Torr yields methylcyclobutane with a quantum yield ø = 0.1, not ethylcyclopropane as was previously thought. (Ethylcyclopropane is formed in trace quantities.) The photostationary state for the Hg* sensitization of the 2‐pentenes is confirmed to correspond to the concentration ratio [trans]/[cis] = 1.00. Trans‐1,2‐dimethylcyclopropane is a product of the Hg* photosensitization of 1‐pentene. The major products of the Hg* photosensitization of trans‐1,2‐dimethylcyclopropane at 80 Torr are 3‐methyl‐1‐butene, trans‐ and cis‐2‐pentene and cis‐1,2‐dimethylcyclopropane which are all formed with quantum yields near 0.1 and in the ratios 1.04:1.07:1.00:1.45.