bluuebunny/crossref_metadata_2025_split huggingface dataset:
«Alkaloide» in tierischem und menschlichem Gewebe. 6. Mitteilung [1] [2]. Synthese und absolute Konfiguration chiraler 2, 3, 10, 11 ‐ Tetrahydroxy‐8‐methyl‐berbine [3]
Authors: Bruderer Hans , Metzger Jean , Brossi Arnold , Daly John J. 
Published: December 2004

Synthesis and absolute configuration of chiral 2, 3, 10, 11‐tetrahydroxy‐8‐methylberbines [3].The synthesis and absolute configuration of the four optically active berbines Xa, b and XIa, b are described. These compounds consitute potential ‘alkaloids’ obtained by condensation of either R‐(+) or S‐(−)‐norlaudanosoline (THP, III) with acetaldehyde, a major metabolite of ethanol.
Aspects of Cyclization Reactions of 2,2′‐Diaminoazobenzene and 1,2‐Bis(2‐aminophenylazo)benzene macrocyclic Aza compounds, II
Authors: Skrabal Peter , Hohl‐Blumer Magadalena 
Published: December 2004

AbstractCyclization of diamine 5 with phthalaldehyde and of diamine 6 with glyoxal results in formation of the macrocyclic amino alcohol 8 and the rearrangement product 16, respectively. The properties and stability of 8 and the reactions of 6 with other bifunctional molecules are discussed.
Heterotricyclodecane XXI 2‐Aza‐7‐thia‐twistane (bzw. 2‐Thia‐7‐aza‐twistane)
Authors: Szczepanski Henry , Ganter Camille 
Published: December 2004

2‐Aza‐7‐thia‐twistanes (or 2‐thia‐7‐aza‐twistanes, respectively)The suitably substituted 9‐thiabicylo[3.3.1]nonanes 7–9 and 17 were synthesized and subsequently cyclized to the 2‐aza‐7‐thia‐twistanes 21–23 and 19, respectivelly, from which several other twistane derivatives (20 and 24–29) were prepared.
Réactions d'addition‐élmination à partir d'hétérocycles germaniés du type . III. Cas des diéthyl‐2,2‐germa‐2‐oxazolidines‐1,3 (R = et; X = O; Y = NH, NMe)
Authors: Dousse Gabriel , Lavayssière Hélène , Satgé Jacques 
Published: December 2004

Addition‐elimination reactions from germanium heterocycles . III. 2,2‐Diethyl‐2‐germa‐1,‐3‐oxazolidines (R = Et; X = O; Y = NH, NMe).The reactions of 2,2‐diethyl‐2‐germa‐1,3‐oxazolidines with heterocumulenes (PhNCO, PhNCS, CS2, CO2, CH2CO) and carbonyl compounds (aldehydes and ketones) are studied. Generally, monoinsertion derivatives are formed by addition of one molecule of the unsaturated compound accross the GeN bond. This bond is always the most reactive center of the molecule. In the case of the carbonyl compounds used, diinsertion may occur in a second step by a further addition across a GeO bond. Generally, this latter reaction is reversible. By thermal eliminat on of (Et2GeO)n or (Et2GeS)3 the monoaddition derivatives yield the corresponding oxazolidines and thiooxazolidines. The mechanisms of these reactions are discussed.
Neue, ungewöhnlich verlaufende Arylierungen der 1,5‐Dihydroxy‐4,8‐diaminoanthrachinon‐2,6‐disulfonsäure mit Kresolen
Authors: Adam Jean‐Marie , Hindermann Peter , Winkler Tammo 
Published: December 2004

A novel course of a phenylation reaction of 1,5‐dihydroxy‐4,8‐diaminoanthraquin‐one‐2,6‐disulfonic acid with cresols.The arylation of 1,5‐dihydroxy‐4,8‐diaminoanthraquinone‐2,6‐disulfonic acid with m‐cresol in conc. sulfuric acid gives in the presence of boric acid a mixture of monosulfonic acids which differ in the substitution of the m‐cresol moiety. The main product (8, 95%) is substituted at the p‐position to the methyl group, the side product (12, 5%) at the p‐position to the OH group. The monosulfonic acid 8, which could not be isolated is further sulfonated under the reaction conditions to the disulfonic acid 9. In the case of o‐cresol, the cresol moiety is substituted in the p‐position (16) to OH group and in the case of p‐cresol in the o‐position (20) to OH group. The obtained monosulfonic acids 16 and 20 resp. are partially sulfonated further under the reaction conditions. The new structures are elucidated by 1H‐ and 13C‐NMR. spectroscopy and the pattern of arylation reaction with phenol is discussed.
Lokalisierung der Ketogruppe in Inandenin‐onen. 160. Mitteilung über Alkaloide
Authors: Guggisberg Armin , Veith Hans‐Jürgen , Hesse Manfred , Schmid Hans 
Published: December 2004

Localization of the keto group in Inandenin‐ones.By Schmidt degradation of the spermidine alkaloids inandenine‐12‐on (1) and inandenine‐13‐on (2) from Oncinotis inandensis followed by hydrolysis, acetylation and esterification four different types of products were obtained: the dicarboxylic diesters 9 and 10, the ω‐amino‐carboxylic esters 11 and 12, the acetylated polyamines 14 and 15, and the acetylated triaminecarboxylic esters 16 and 17. By GLC. and mass spectral analysis of these degradation products, and by comparison with synthetic compounds it was possible to confirm the structures 1 and 2. The same alkaloid mixture (1+2) was obtained from the leaves of Oncinotis nitida BENTH.
Cryptates XXIV: Structure and stability of mononuclear and binuclear cation inclusion complexes of cylindrical macrotricyclic ligands
Authors: Lehn Jean‐Marie , Simon Jacques 
Published: December 2004

AbstractThe cylindrical macrotricyclic ligands 1–3 yield inclusion complexes, [3]‐cryptates, with various metal cations. NMR. studies indicate the successive formation of a mononuclear and a binuclear complex. The former is probably unsymmetrical undergoing fast intramolecular cation exchange; the latter is symmetrical, with a cation located on each macrocyclic subunit of the macrotricyclic system. A heteronuclear (Ag2+, Pb2+) complex has been observed. The stability constants of the mononuclear and binuclear alkali and alkaline‐earth cation complexes of ligands 1–3 have been determined by potentiometric methods. The stabilities are comparable to those of the complexes of the isolated macrocyclic subunit 5b. The binuclear complexes are almost as stable as the mononuclear one even in highly charged species like for instance the complex of ligand 2 with two barium cations. Cylindrical macrotricyclic ligands are topologically well suited for the designed positioning of two metal cations in a binuclear inclusion complex.
Über Pterinchemie. 58. Mitteilung [1]. Sterische Eigenschaften von acylierten 5,6,7,8‐Tetrahydropterinen. Rotameren von 5‐Trifluoracetyl‐tetrahydropterin‐Derivaten
Authors: Weber Rudolf , Viscontini Max 
Published: December 2004

Sterochemical Properties of the Acylated 5,6,7,8‐Tetrahydropterines. Rotameres of the 5‐Trifluoroacetyl‐tetrahydropterine Derivatives6‐Methyl‐ and 6,7‐dimethyl‐5,6,7,8‐tetrahydropterine are acylated with the anhydrides of acetic acid and trifluoroacetic acid. It is shown that the reactivity of the nitrogen otoms increases in the following order: N(3), N(8), N(2′) and N(5). Two rotameres are present in the 1H‐NMR. spectra of the N(5)‐trifluoroacetates, but not in those of the N(5)‐acetates.
Über Pterinchemie. 59. Mitteilung [1]. Konformationsanalyse von acylierten 5,6,7,8‐Tetrahydropterinen
Authors: Weber Rudolf , Viscontini Max 
Published: December 2004

Conformational Analysis of Acylated 5,6,7,8‐TetrahydropterinesThe conformation of N(5)‐acetates, and of N(5)‐ and N(8)‐trifluoroacetates, respectively, of 6‐methyl‐ and cis‐6, 7‐dimethyl‐tetrahydropterines is studied by 1H‐NMR. spectroscopy. It is shown that the methyl group next to the acylated nitrogen atom is in quasi‐axial position.
Gasförmige Komplexe zwischen Kobaltchlorid und Indiumchlorid
Authors: Dienstbach Falko , Emmenegger Franzpeter 
Published: December 2004

Gaseous Complexes between Cobaltchloride and IndiumchlorideThe equilibria (1) and (2):

were investigated by optical spectroscopy and by vapour pressure measurements using the transpiration method:

Together with thermodynamic data from the literature the results obtained allow a complete description of all heterogeneous solid/gas as well as the homogeneous equilibria in the gas phase of the system CoCl2/InCl3 in the temperature range 500–800°.
Réactions chimiques oscillantes (type Belousov‐Zhabotinskii) impliquant des cétones cycliques et aliphatiques
Authors: Farage Vincent J. , Stroot Philippe , Janjic Désimir 
Published: December 2004

Oscillating Chemical Reactions (Belousov‐Zhabotinskii type) involving cyclic and aliphatic KetonesFour ketonic compounds (cyclohexanone, cyclopentanone, butanone, and 3‐pentanone) have been found to generate chemical oscillations in the BrO3−/Ce4+/ketone system. The effect of changes in concentrations of the reagents has been investigated and differences in behaviour with other systems found. The dependence of these reactions on temperature has been studied and activation energies calculated.
Etudes photochimiques en série hétérocyclique. V. Mise en évidence d'oxazoles par photooxydation de thiazoles
Authors: Vernin Gaston , Treppendahl Svend , Metzger Jacques 
Published: December 2004

Formation of oxazoles as by‐products of photooxydation of thiazolesIn the presence of air, light (high pressure mercury lamp) and iodine as sensitizer, benzene solution of arylthiazoles 2, 3 and 13 (see scheme 1) were converted into a mixture of photoisomers and aryloxazoles (see scheme 2).Upon shorter times of irradiation under oxygen in chloroform containing methylene blue as a sensitizer 2,4,5‐triphenylthiazole (7) is converted in 2,4,5‐triphenyloxazole.Under usual photooxidation conditions, in methanol as solvent, most of arylthiazoles studied gave a mixture of nitriles, amides, acids esters and diketones. In the case of thiazole 7, the corresponding oxazole was also found.A possible mechanism for the photochemical oxidation of arylthiazoles to aryloxazoles, via 2,5‐ and 4,5‐endo‐peroxides, may be proposed (see schemes 5 and 6).
Das unterschiedliche massenspektrometrische Fragmentierungsverhalten von Lysinmethylester und dessen N,N′‐Diacetylderivat. 27. Mitteilung über das massenspektrometrische Verhalten von Stickstoffverbindungen
Authors: Roessler Felix , Hesse Manfred 
Published: December 2004

The Different Behaviour of Lysine Methyl Ester and its N,N′‐Diacetyl Derivative under Electron ImpactThe base peak in the spectrum of lysine methyl ester is due to the fragment ion C5H10N (m/e 84), for which the cyclic structure g (Scheme 1) is deduced. During its formation from the [M‐COOCH3]‐ion an equilibration of both nitrogen atoms takes place (ion c, Scheme 1). The cyclic nature of ion m/e 84 is in agreement with the intensity of the corresponding ions in the spectra of homologues of lysine methyl ester (Fig. 1). Although in comparison with lysine methyl ester (1) N,N′‐diacetyl‐lysine methyl ester (7) shows the same general fragmentation pathway with formation of the ions [M‐COOCH3] and [M‐COOCH3‐H2NCOCH3] (m/e 126), the exact fragmentation mechanism proves to the different. Two mechanisms are discussed for the formation of the ion m/e 126 from 7 (Schemes 2 and 3). The results are based on the spectra of labelled derivatives.
Synthese und Umwandlungen von Isoxazolidin‐Nucleosiden
Authors: Vasella Andrea 
Published: December 2004

Synthesis and Transformations of Isoxazolidine‐NucleosidesReaction of the oxime 12 with formaldehyde, acetaldehyde or acetone in the presence of methacrylic acid methylester leads in a highly stereoselective 1,3 dipolar cycloaddition of the corresponding nitrones to the protected isoxazolidine ribosides 13, 14, 20, 21 and 26 (Scheme 1 and 2).Using a new, mild procedure to effect detriylation, the cycloaddition products were transformed into the alcohols 16–19, 22–25 and 27.Cleavage of a mixture of the glycosides 16 and 17 yielded the N‐unsubstituted isoxazolidine 29 in 65% optical purity while the cleavage of 27 gave optically pure 28.Alternatively, the isoxazolidine ribosides 13, 14, 16–18 and 26 were transformed via reductive cleavage of the isoxazolidine N‐O bond and subsequent lactamization into the corresponding pyrrolidinone‐ribosides 30, 33, 35, 42, 49 and 50, the ribitolyl pyrrolidinones 31, 34, 36–39 and 43–46 (see Scheme 4) and the ribitolyl isoxazolidine 47.
Notiz über Methoden zur Umwandlung von 1,2‐Dicarbonsäuren in konjugiert ungesättigte Monocarbonsäuren. Über synthetische Methoden, 12.Mitteilung
Authors: Gygax Peter , Eschenmoser Albert 
Published: December 2004

A Note on Methods for the Transformation of 1,2‐Dicarboxylic Acids into α, β‐Unsaturated Monocarboxylic Acids.A model study using the Diels‐Alder adduct of maleic anhydride and butadiene (see scheme 3) exemplifies the conversion of the succinic acid type of structure into α, β‐unsaturated carboxylic acids via two complementary fragmentations of 3,6‐dioxo‐perhydro‐1,2‐oxazine derivatives.
Asymmetric Hydroformylation of α‐[2H]‐Styrene. Preliminary Communication
Authors: Stefani Annibale , Tatone Dante 
Published: December 2004

AbstractThe hydroformylation of α‐[2H]‐styrene in the presence of an asymmetric rhodium‐catalyst afforded two optically active isomeric aldehydes. The origin of the asymmetric induction is discussed on the basis of the chirality and the optical purity of the two products.
Exo‐ und endo‐Tricarbonyleisenkomplexe von bicyclischen 2,3‐Dimethylidenverbindungen
Authors: Steiner Ulrich , Hansen Hans‐Jürgen , Bachmann Kurt , Von Philipsborn Wolfgang 
Published: December 2004

Exo‐ and endo‐Tricarbonyliron Complexes of Bicyclic 2,3‐Dimethylidene Compounds.The preparation of exo‐ and endo‐tricarbonyliron complexes (exo‐ and endo‐5, ‐6, ‐8, and 9) of 2,3‐dimethylidene‐5‐bicyclo[2.2.1]heptene(1), ‐bicyclo[2.2.1]‐heptane (2), ‐5‐bicyclo[2.2.2]octene (3) and ‐bicyclo[2.2.2]octane (4) is described. The complexes are obtained by thermal reaction of the bicyclic butadienes with di‐ironenneacarbonyl in hexane solution. exo‐ and endo‐5 are also formed photochemically from ironpentacarbonyl and 1 in pentane solution at −35°. The structural assignment of exo‐ and endo‐5 and ‐6 is based on their mass‐spectra and on coordination shifts in 1H‐ and 13C‐NMR.‐spectra exo‐ and endo‐6 are correlated with exo‐ and endo‐5, respectively, by hydrogenation. Hydrogenation of the uncomplexed double bond in exo‐ and endo‐5 occurs in both complexes from the exo side as shown by deuteration experiments. The free ligand 1 reacts in the same stereospecific manner.
Dysidin, ein neuartiger, chlorhaltiger Naturstoff aus dem Schwamm Dysidea herbacea
Authors: Hofheinz Werner , Oberhänsli Willi E. 
Published: December 2004

Dysidin, a novel chlorine containing natural product from the sponge Dysidea herbaceaDysidin (1) has been isolated from the marine sponge Dysidea herbacea. It structure has been determined by degradation studies and spectroscopic methods. The synthesis of a degradation product is described. The relative and absolute configuration is established by X‐ray diffraction methods.
Zur Regioselektivität von Cycloadditionen photochemisch erzeugter Benzonitril‐isopropylide. 51. Mitteilung über Photoreaktionen
Authors: Gerber Ulrich , Heimgartner Heinz , Schmid Hans , Heinzelmann Willy 
Published: December 2004

On the regioselectivity of cycloaddition reactions of photochemically generated benzonitrile‐isopropylidesThis paper deals with the physical and chemical differences of zwitterionic benzo‐nitrile‐isopropylides, which differ by a p‐substituent in the phenyl ring (H, F, OCH3; Scheme 2). These dipolar species (4–6) are produced by irradiation of the corresponding 2 H‐azirines (1–3; Scheme 1) in a 2‐methylpentane glass at −185°. Their UV. spectra are reproduced in the Figure. The spectra of 4 and 5 are characterized by an ‘aromatic band’ at short wavelength, and a longer wavelength band at approximately 275 nm, which is considered to be characteristic of the nitrile‐ylide system. The UV. spectrum of the methoxy derivative 6, which shows a broad absorption at 260 nm, arises by an addition of the ‘nitrile‐ylide band’ and the anisole band. The three dipolar species 4–6 do not show any significant differences in the regioselectivity of the cycloaddition with methyl α‐methacrylate even though F and OCH3 have quite different σ‐constants (Scheme 1). The addition according to modus A is very much preferred (B/A = 0,076). – It seems, that the substituents F and OCH3 do not affect the physical and chemical behaviour of the parent benzonitrile‐isopropylide (4). All three dipolar species 4–6 react regiospecifically according to modus A with methyl trifluoroacetate (Scheme 1). The regioselectivity is reduced in the cycloaddition of 4 with methyl propiolate and ethyl phenylpropiolate (B/A = 0,04 and 0,28, respectively). The reduced regioselectivity in the latter case may be attributed to a reduced polarity of the triple bond in the dipolarophile.
Metallkomplexe von N‐substituierten 3‐Imino‐isoindolinonen
Authors: L'Eplattenier François A. , Frey Christoph , Rihs Greti 
Published: December 2004

Metal Complexes of N‐substituted 3‐Imino‐isoindolinonesThe condensation of 3‐imino‐isoindolinone 4 and benzimidazoles or benzthiazoles containing activated methyl‐, methylen‐ or aminogroups (5 resp. 6), yields the iso‐indolinone‐ligands 1 and 2. Metal ions such as Co2+, Ni2+, Cu2+ and Zn2+ form (1:2)‐complexes with these ligands of very high chemical and photochemical stabilities. The magnetic properties of these complexes indicate that the geometry around the central atoms is distorted tetrahedral. A X‐ray diffraction study of one of the Co(II)‐complexes confirms these findings.
Metal ion exchange in square planar Nickel and Palladium Mercaptoethylamine Complexes
Authors: Reichert R. , Schläpfer C. W. 
Published: December 2004

AbstractAustauschversuche mit radioaktivem Nickel zeigen, dass Ni2+ und Pd2+ in Mercaptoäthylamin(MEA‐)‐Komplexen austauschbar sind. Aus UV./VIS.‐ und 1H‐NMR.‐spektroskopischen Daten geht hervor, dass die Anordnung der Metallionen in Ni2Pd(MEA)4Cl2 symmetrisch ist (Ni Pd Ni), in NiPd2(MEA)4Cl2 dagegen asymmetrisch (Ni Pd Pd).
D(−)‐ and L(+)‐γ‐Carboxyglutamic Acid (Gla): Resolution of Synthetic Gla Derivatives
Authors: Märki Walter , Oppliger Max , Thanei Peter , Schwyzer Robert 
Published: December 2004

AbstractThe chemical resolution of γ,γ′‐di‐t‐butyl DL‐N‐benzyloxycarbonyl‐γ‐carboxy‐glutamate is described in detail (preliminary account see [1]). The D (−)‐derivative was obtained as a crystalline quinine salt, and the L (+)‐derivative as a crystalline salt with (−)‐ephedrine in yields of 44 and 70%, respectively. Physical data are indicated for the enantiomers of γ,γ′‐di‐t‐butyl N‐benzyloxycarbonyl‐γ‐carboxyglutamate, γ,γ′‐di‐t‐butyl γ‐carboxyglutamate, and γ‐carboxyglutamic acid. The absolute configurations and optical purities of the γ,γ′‐di‐t‐butyl (+)‐ and (−)‐N‐benzyloxycarbonyl‐γ‐carboxyglutamates were determined by removal of the protecting groups and decarboxylation to optically active glutamic acid.
Azimine. II. Synthese und thermische Fragmentierung von cis‐ und trans‐2,3‐Diphenyl‐1‐phthalimido‐2,3‐di[15N]‐azimin
Authors: Leuenberger Christian , Karpf Martin , Hoesch Lienhard , Dreiding André S. 
Published: December 2004

Azimines. IITeil I, siehe [1].

.
Preparation and Thermal Fragmentation of cis‐ and trans‐2,3‐Diphenyl‐1‐phthalimido‐2,3‐di[15N]‐azimine

Teilweise vorgetragen in der Versammlung der Schweizerischen Chemischen Gesellschaft am 8./9. Oktober 1976 in Genf und als Autoreferat veröffentlicht [2].
cis‐ and trans‐2,3‐Diphenyl‐1‐phthalimido‐2,3‐di[15N]‐azimine (11 and 12) wer synthesized from cis‐di[15N]‐azobenzene (10) and phthalimido‐nitrene (2), the latter generated by lead tetraacetate oxidation of N‐aminophthalimide (1). Useful information was obtained from the comparison of several data of 11 and 12 with those of the unmarked diphenyl‐azimines 5 and 6 (R = C6H5).The 15N‐ and 13C‐NMR. spectra of 11 and 12 were interpreted to furnish additional evidence for the azimine structure and for the indicated configurations. The IR. spectra permitted identification of two bands in the 1200 to 1450 cm−1 region, probably characteristic for the functionality of diaryl‐phthalimido‐azimines. Comparison of the mass spectrum of 11/12 with that of the unmarked analogues 5/6 (R = C6H5) permitted the interpretation of the fragmentation path of 1‐phthalimidoazimines. The major path may be the purely thermal decomposition to 13 and 7 (R = C6H5), respectively. Two other competing fragmentation paths are discussed.Prolonged thermolysis of 11 at 61° in solution gave 83% of N,N′‐diphenyl‐N N′‐phthaloyl‐di[15N]‐hydrazine (13) of 98% isotope purity, which means that the imide nitrogen atom and N(1) of the azimine function are removed in this reaction. A mechanism passing through an intermediate cyclic tetrazene 16 is considered.Benzocyclobutenedione (14) added to trans‐azobenzene (4, R = C6H5) under the influence of a high pressure lamp in a quarz apparatus to give N,N′‐diphenyl‐N,N′‐phthaloyl‐hydrazine (7, R = C6H5). This reaction was found not to take place in the dark, even after prolonged heating in trichloromethane.
Photochemistry of Chlorinated 2‐Cycloalkenones
Authors: Altmeyer Isabelle , Margaretha Paul 
Published: December 2004

AbstractThe 6‐chloro‐2‐cyclohexenones 3, 6 and 11, and the 5‐chloro‐2‐cyclopentenone 15 were newly synthesized. The results obtained with compounds 3 and 15 in photocycloadditions to olefins show that the oxetane vs. cyclobutane product ratio is reduced by the substitution of florine by chlorine in the α′ ‐position of the enone. No oxetanes are formed in the intramolecular photocycloaddition of 6. Compound 11 does not photoadd to olefins. The newly synthesized 2‐chloro‐3‐cyclohexenones 8 and 9 are also photostable towards light of λ=366 nm, but π‐π*‐excitation (λ=254 nm) in pentane leads to the formation of 4,4‐dimethylcyclohexanone (29).
Isolation and Identification of Three Major Metabolites of Retinoic Acid from Rat Feces
Authors: Hänni Ralph , Bigler Felix 
Published: December 2004

AbstractFollowing the intraperitoneal administration of high doses of 14C‐ and 3H‐ labelled retinoic acid (1) to rats, three major metabolites and the intact compound were isolated from the feces in microgram amounts by use of column, thin‐layer and high‐pressure liquid chromatography. Their structures were elucidated by mass spectrometry and Fourier Transform 1H‐NMR. spectroscopy as 2 (all‐trans‐4‐oxoretinoic acid), 3 (7‐trans‐9‐cis‐11‐trans‐13‐trans‐5′‐hydroxy‐retinoic acid).Hydroxylation of the 5‐methyl group of the cyclohexene ring, oxidation of the cyclohexene ring in position 4 and cis‐trans isomerisation of the nonatetraenoic acid side chain were the reactions, which produced these products from retinoic acid. The metabolites 2 and 4 each accounted for about 4% of the radioactivity administered. The metabolite 3 and the parent compound accounted for about 16% and 17% of the dose, respectively.
Nouveaux exemples de radicaux libres stables de dérivés hétérocycliques de sucres. Communication préliminaire
Authors: Tronchet Jean M. J. , Ojha‐Poncet Joëlle , Winter‐Mihaly Eva , Kohler Boris , Geoffroy Michel 
Published: December 2004

Some more examples of stable free radicals of carbohydrate heterocyclic derivatives2‐Glycosyl‐4,4,5,5‐tetramethylimidazoline‐ 3‐oxide‐1‐oxyls and 2‐glycosyl‐4,4,5,5‐tetramethylimidazoline 1‐oxyls have been prepared in nine carbohydrate series, which proves the generality of the method. The hyperfine coupling constant between the free electron and the α‐proton of the glycosyl group is never very large (0‐2.3 G) but a correlation between its value and the structure of the aglycone has been noted. Free radicals of that type, stable in aqueous solutions, are potentially interesting for biological studies.