摘要:

AbstractThe behaviour of di‐(1‐anthraquinonyl)‐amine, when cyclised in pyridine‐aluminium chloride or pure aluminium chloride fusions, has been compared. The formation of blue educt complexes with aluminium chloride in the latter case has been revealed as a factor which inhibits cyclisation. The results are discussed and generalised, classifying carbazolation of anthrimides as an intramolecularScholl‐type

ISSN:0018-019X    

DOI:10.1002/hlca.19710540302

出版商:WILEY‐VCH Verlag GmbH    

年代:1971

数据来源: WILEY

摘要:

AbstractThe photoelectron spectra of fulvene (II) and of 3,4‐dimethylene‐cyclobutene (III) have been recorded. The PE. bands are correlated, in order of increasing ionisation potentials, with the following orbitals: II: 1a2(π), 2b1(π), 7b2(π), 1b1(π); III: 2b1(ω), 1a2(π), 10a1(ω), 8b2(ω), 1b1(π). This assignment is based on a semi‐quantitative perturbation MO‐model and on the SCF‐LCAO‐MO calculations reported byPraud,Millie&Berthier[5] for

ISSN:0018-019X    

DOI:10.1002/hlca.19710540303

出版商:WILEY‐VCH Verlag GmbH    

年代:1971

数据来源: WILEY

摘要:

AbstractA model for the computation of free energies of hydration and coordination numbers of cations using easily available parameters is described. For 27 mono‐, di‐ and trivalent cations the mean deviation of the calculated from the experimental ΔG°Hvalues is 3.9%. All the computed coordination numbers agree with experimental

ISSN:0018-019X    

DOI:10.1002/hlca.19710540304

出版商:WILEY‐VCH Verlag GmbH    

年代:1971

数据来源: WILEY

摘要:

AbstractDie erste Synthese eines 6, 6‐disubstituierten Tetrahydropterins, nämlich des 6‐Aminomethyl‐6‐methyl‐5, 6, 7, 8‐tetrahydropterins, wird beschrieben: Das durch Anlagerung von Blausäure an 6‐Methyl‐7, 8‐dihydropterin entstandene 6‐Cyano‐6‐methyl‐5, 6, 7, 8‐tetrahydropterin wird acetyliert, reduziert und anschliessend desacetyliert. Entgegen unserer Erwartung bildet das 6‐Aminomethyl‐6‐methyl‐tetrahydropterin bei der Oxydation durch Luftsauerstoff unter physiologischen Bedingungen kein Parachinoid‐dihydropterin, sondern wird direkt zu 6‐Methyl‐7, 8‐dih

ISSN:0018-019X    

DOI:10.1002/hlca.19710540305

出版商:WILEY‐VCH Verlag GmbH    

年代:1971

数据来源: WILEY

摘要:

AbstractIrradiation of benzofurazan (1) in benzene solution yields the azepine derivative3as the main photoproduct. Addition of methanol in the dark to the irradiated benzene solution of1results in the isolation of3together with a new product, methyl‐1‐cis, 3‐cis‐N‐(4‐cyano‐buta‐1, 3‐dien‐1‐yl)‐carbamate (1‐cis, 3‐cis‐2). Irradiation of1in methanol solution gives a mixture of the stereoisomeric methyl N‐(4‐cyano‐buta‐1, 3‐dien‐1‐yl)‐carbamates, from which the 1‐trans, 3‐cisisomer of2could be isolated in pure form.The observed photoproducts are formedviathe reactive intermediatesa, a nitrile‐(nitrile oxi

ISSN:0018-019X    

DOI:10.1002/hlca.19710540306

出版商:WILEY‐VCH Verlag GmbH    

年代:1971

数据来源: WILEY

摘要:

AbstractIn addition to the known alkaloid peganine (1) from young plants of the AcanthaceaAdhatoda vasica, the base anisotine (7) and the three new alkaloids vasicoline (4), adhatodine (5), and vasicolinone (6) were isolated and analysed. Mainly on the basis of spectral properties (UV., IR., NMR. and mass spectrometry) the structures were assigned. By atmospheric oxygen the bases vasicoline and adhatodine are oxidized in position7; it is therefore remarkable that these bases are present as such in the plant.

ISSN:0018-019X    

DOI:10.1002/hlca.19710540307

出版商:WILEY‐VCH Verlag GmbH    

年代:1971

数据来源: WILEY

摘要:

AbstractTreize composés d'addition d'aldéhydes et de cétones ont été préparés avec divers acides deLewis(HgCl2, ZnCl2, CdCl2, SbCl5et NbCl5). A l'état solide, ils possèdent une stoechiométrie bien définie. Pour tous ces composés d'addition, la fréquence de vibration ω(CO) de la base deLewis(1600–1700 cm−1) subit un abaissement marqué Δω, allant de −15 cm−1(HgCl2) à −167 cm−1(NbCl5), ce qui prouve que leur formation est due à l'établissement d'une liaison de coordination entre l'atome d'oxygène donneur et l'acide deLewis.Il existe une bonne corrélation linéaire entre ω(CO) des aldéhydes aromatiques ou entre Δω de leurs composés d'addition avec SbCl5et la constante ωrdu type deHammettou le potentiel de demi‐vague de la réduction polarographique.Les auteurs ont calculé les constantes de force de H2CO·SbCl5en se référant aux valeurs expérimentales des fréquences de vibration, en appliquant la méthode FG à un modèle plan de 5 masses. L'abaissement deFCOest d'environ 7%, alors que Δω/ω vaut environ −5%. La variation de longueur de la liaison carbonyle contribue pour 55,7% à l'énergie

ISSN:0018-019X    

DOI:10.1002/hlca.19710540308

出版商:WILEY‐VCH Verlag GmbH    

年代:1971

数据来源: WILEY

摘要:

AbstractDas als Substanz H bezeichnete biologische Umwandlungsprodukt der Fusarinsäure (I) wurde alsS(+)‐Fusarinolsäure (VIII) erkannt. Beweisend für die Konstitution VIII war die Umwandlung der Dehydrofusarinsäure (V) über dierac.‐Fusarinolsäure (Ia) in das (+)‐Fusarinolsäure‐(+)‐camphersulfonat (VIIIa), welches mit einem aus natürlicher (+)‐Fusarinolsäure (VIII) hergestellten Präparat identisch war. DieS‐Konfiguration der natürlichen (+)‐Fusarinolaäure ergab sich aus der Synthese von VIII bzw. VIIIa aus der Dinatriumverbindung VI des 2‐Carboxy‐5‐methyl‐pyridins and S(+)‐2‐Benzyloxy‐propyljodid (VIIa), welches konfigu

ISSN:0018-019X    

DOI:10.1002/hlca.19710540309

出版商:WILEY‐VCH Verlag GmbH    

年代:1971

数据来源: WILEY

摘要:

AbstractFrom cultures of aPhomaspecies (strain S729) (Fungi imperfecti) gentisylalcohol (1), toluhydroquinone (3), and two new metabolites, gentisylacetal (2) and chlorogentisylalcohol (4), have been isolated. The structure of2was proven by cleavage to gentisylalcohol (1) and acetaldehyde, and by resynthesis from these moieties. The synthesis of chlorogentisylalcohol (2,5‐dihydroxy‐3‐chloro‐benzyl alcohol) (4) and its two isomers5and6from chlorohydroquinone (10)viathe aldehydes7,8, and9respectively established the structure of this met

ISSN:0018-019X    

DOI:10.1002/hlca.19710540310

出版商:WILEY‐VCH Verlag GmbH    

年代:1971

数据来源: WILEY

摘要:

AbstractConcerted electrocyclic processes which are forbidden according to the symmetry conservation rules ofWoodward&Hoffmann, may nevertheless take place at low activation energies. The necessary conditions are exemplified by the unique case of thetrans‐15, 16‐dimethyl‐dihydropyrene ⇌ 15, 16‐dimethyl‐[2.2]metacyclophane‐4,9

ISSN:0018-019X    

DOI:10.1002/hlca.19710540311

出版商:WILEY‐VCH Verlag GmbH    

年代:1971

数据来源: WILEY