摘要:

AbstractTwo new syntheses of spiro[4.4]nonane‐1, 6‐dione (I) are described: one by rearrangement of 1,6‐epoxy‐bicyclo[4.3.0]‐nonane‐2‐one (IV) with boron trifluoride, the other by an acid catalyzed, intramolecularClaisencondensation of 4‐(2‐oxocyclopentyl)‐butyric acid. Spiro[4.4]‐nonane‐1,6‐dione is converted intotrans, trans‐spiro[4.4]nonane‐1,6‐diol which is resolved into enantiomers via the diastereomeric esters with (−)‐camphanic acid. (+)‐(5S)‐Spiro[4.4]nona‐1,6‐diene (III) is prepared from (1R, 6R)‐trans,trans‐spiro[4.4]nonane‐1,6‐diol (II) by pyrolysis of the corresponding bis‐4‐methylphenyl‐thionocarbonate. This modification of theChugaevreaction is particularly useful with sterically hindered alcohols which cannot be converted into S‐me‐thylxanthates. The circular dichroism, UV.‐ and NMR.‐spect

ISSN:0018-019X    

DOI:10.1002/hlca.19720550702

出版商:WILEY‐VCH Verlag GmbH    

年代:1972

数据来源: WILEY

摘要:

AbstractThe 3‐amino‐3,5‐didesoxy‐1,2‐O‐isopropylidene‐α‐D‐ribofuranose and ‐β‐D‐lyxo‐furanose and several derivatives thereof have been prepared by hydride reduction

ISSN:0018-019X    

DOI:10.1002/hlca.19720550703

出版商:WILEY‐VCH Verlag GmbH    

年代:1972

数据来源: WILEY

摘要:

AbstractNous avons pu montrer à l'aide de substances radioactives que l'acide picolique est le précurseur immédiat de la proferrorosamine A. L'acide glutamique peut être transformé parPseudomonas roseus fluorescensen acide picolique puis être incorporé dans la partie pyridinique du propigment tandis que les atomcs de carbone formant le noyau pyrrolinique provienncnt d'autrcs métabolites que nous n'avons pas encore identifiés. La lysine semble jouer le même rêle que I'acide glutaminique et ceci d'une manière encore pl

ISSN:0018-019X    

DOI:10.1002/hlca.19720550704

出版商:WILEY‐VCH Verlag GmbH    

年代:1972

数据来源: WILEY

摘要:

Abstract2‐(p‐Tolyl)‐2H‐benzotriazole und 2‐Phenyl‐5‐methyl‐2H‐benzotriazole können mit Anilen aromatischer Aldehyde in Dimethylformamid in Gegenwart von Kaliumhydroxid in 2‐(Stilben‐4‐yl)‐2H‐benzotriazole bzw. 2‐Phenyl‐5‐styryl‐2H‐benzotriazole über geführt werden («Anil‐Synthese»). Durch Einführung von Substituenten wie Chlor oder Methoxy gruppen kann die Lage des Fluoreszenzspektrums in Dimethylformamid eine erhebliche batho

ISSN:0018-019X    

DOI:10.1002/hlca.19720550705

出版商:WILEY‐VCH Verlag GmbH    

年代:1972

数据来源: WILEY

摘要:

AbstractChemical degradations and spectroscopic investigations of the macrolide antibiotics venturicidin A and B are described. In combination with an X‐ray crystallographic analysis they lead to complete structure

ISSN:0018-019X    

DOI:10.1002/hlca.19720550706

出版商:WILEY‐VCH Verlag GmbH    

年代:1972

数据来源: WILEY

摘要:

AbstractDensitometric techniques are common for thein situquantitative investigations of thin‐layer chromatograms. The present paper concernes investigations of the distribution of substances within their spots by the aid of radio‐isotopes. The distribution depends on the kind of adsorption mechani

ISSN:0018-019X    

DOI:10.1002/hlca.19720550707

出版商:WILEY‐VCH Verlag GmbH    

年代:1972

数据来源: WILEY

摘要:

AbstractThe preparation of cyanine dyes by coordination of cyanine dye bases with transition metals is described. The significance of these complexús for the realization of an excitonic high temperature superconductor is discussed

ISSN:0018-019X    

DOI:10.1002/hlca.19720550708

出版商:WILEY‐VCH Verlag GmbH    

年代:1972

数据来源: WILEY

摘要:

AbstractThe reaction of norbornene with lead tetraacetate is found to be much more complex than previously reported. In acetic acid and in benzene, thesyn‐7‐norbornenyl, 3‐nortricyclyl, andsynandanti‐7‐acetoxy‐exo‐2‐norbornyl acetates were characterized. In methanol, the isolated products represented most of those expected from the competition of methanol and acetate in the neutralization of the intermediate carbocations. The reaction of norbornene with thallium trinitrate in the above solvents yielded very complex mixtures besides the above mentioned products which were formed in

ISSN:0018-019X    

DOI:10.1002/hlca.19720550709

出版商:WILEY‐VCH Verlag GmbH    

年代:1972

数据来源: WILEY

摘要:

AbstractThecis‐oxa‐ (13a‐d) and ‐aza‐σ‐bishomobenzene (13 e) derivatives have been synthesized; they are sufficiently stable to be isolated in pure form. On heating,13a‐eare easily isomerized into the π‐bishomobenzene analogues14a‐e, the processes13 a⇄14 a,13 b⇄14band13d⇄14dbeing reversible. Some kinetic and thermodynamic data for these σ, π,bishomobenzene tr

ISSN:0018-019X    

DOI:10.1002/hlca.19720550710

出版商:WILEY‐VCH Verlag GmbH    

年代:1972

数据来源: WILEY

摘要:

Abstract(Z,Z)‐4‐Methyl‐6‐phenyl‐3,5‐hexadien‐2‐one (5) is converted to its (Z,E)‐isomer6at 35° in the dark. This ready, uncatalysedcis,trans‐isomerization is shown to proceed through 2H‐pyran9. Irradiation of either stereoisomeric dienone6, 7or8at 0° produces a photostationary mixture of5, 6, 7and8in which the (Z

ISSN:0018-019X    

DOI:10.1002/hlca.19720550711

出版商:WILEY‐VCH Verlag GmbH    

年代:1972

数据来源: WILEY