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doi: 10.1002/hlca.19710540302pmid: N/A
The 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 intramolecular Scholl‐type reaction.
Heilbronner, E.; Gleiter, R.; Hopf, H.; Hornung, V.; De Meijere, A.
doi: 10.1002/hlca.19710540303pmid: N/A
The 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 by Praud, Millie & Berthier [5] for benzene, II and III.
doi: 10.1002/hlca.19710540304pmid: N/A
A 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°H values is 3.9%. All the computed coordination numbers agree with experimental ones.
Viscontini, M.; Frater‐Schroeder, M.; Argentini, M.
doi: 10.1002/hlca.19710540305pmid: N/A
Die 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‐dihydropterin, Formaldehyd und Ammoniak abgebaut.
Georgarakis, M.; Rosenkranz, H. J.; Schmid, H.
doi: 10.1002/hlca.19710540306pmid: N/A
Irradiation of benzofurazan (1) in benzene solution yields the azepine derivative 3 as the main photoproduct. Addition of methanol in the dark to the irradiated benzene solution of 1 results in the isolation of 3 together 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 of 1 in 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‐cis isomer of 2 could be isolated in pure form.
Johne, S.; Gröger, D.; Hesse, M.
doi: 10.1002/hlca.19710540307pmid: N/A
In addition to the known alkaloid peganine (1) from young plants of the Acanthacea Adhatoda 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 position 7; it is therefore remarkable that these bases are present as such in the plant.
Filippini, Franchino; Susz, Bernard‐P.
doi: 10.1002/hlca.19710540308pmid: N/A
Treize composés d'addition d'aldéhydes et de cétones ont été préparés avec divers acides de Lewis (HgCl2, ZnCl2, CdCl2, SbCl5 et NbCl5). A l'état solide, ils possèdent une stoechiométrie bien définie. Pour tous ces composés d'addition, la fréquence de vibration ω(CO) de la base de Lewis (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 de Lewis.
Steiner, K.; Graf, U.; Hardegger, E.
doi: 10.1002/hlca.19710540309pmid: N/A
Das als Substanz H bezeichnete biologische Umwandlungsprodukt der Fusarinsäure (I) wurde als S(+)‐Fusarinolsäure (VIII) erkannt. Beweisend für die Konstitution VIII war die Umwandlung der Dehydrofusarinsäure (V) über die rac.‐Fusarinolsäure (Ia) in das (+)‐Fusarinolsäure‐(+)‐camphersulfonat (VIIIa), welches mit einem aus natürlicher (+)‐Fusarinolsäure (VIII) hergestellten Präparat identisch war. Die S‐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 konfigurativ mit der L‐Milchsäure verknüpft wurde.
doi: 10.1002/hlca.19710540310pmid: N/A
From cultures of a Phoma species (strain S729) (Fungi imperfecti) gentisylalcohol (1), toluhydroquinone (3), and two new metabolites, gentisylacetal (2) and chlorogentisylalcohol (4), have been isolated. The structure of 2 was 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 isomers 5 and 6 from chlorohydroquinone (10) via the aldehydes 7,8, and 9 respectively established the structure of this metabolite.
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