摘要:

AbstractEthyl and methyltrans‐2,cis‐6‐dodecadienoate, two Bartlett pear constituents, have been prepared by a novel two‐step synthesis: 1,6‐addition of lithium di‐cis‐1‐heptenylcuprate to ethyl or methyltrans‐2,4‐pentadienoate gave exclusively the 3,6‐diolefinic esters, which were isomerized to the desired 2,6‐diolefinic esters. The double‐bond geometry of the vinyl unit is retained

ISSN:0018-019X    

DOI:10.1002/hlca.19720550112

出版商:WILEY‐VCH Verlag GmbH    

年代:1972

数据来源: WILEY

摘要:

AbstractThe NMR. spectra of two acridones and twenty‐two quinacridones in (CD3)2SONaOD are reported. A NMR. technique is described for determining the composition of mixtures of various substituted quinacridones. A general mechanism is proposed for quinacridone formationviacyclodehydration of 2,5‐diarylamino‐terephthalic and 2,5‐diarylamino‐1,4‐benzoquinone‐3,6‐dicarbox

ISSN:0018-019X    

DOI:10.1002/hlca.19720550113

出版商:WILEY‐VCH Verlag GmbH    

年代:1972

数据来源: WILEY

摘要:

AbstractIsotherms for the adsorption of nitrogen (77 K), carbon dioxide (195–247 K) and sulfur dioxide (254–293 K) on polyvinylidene chloride have been measured volumetrically. TheB.E.T.cross‐sectional areas of 18 Å2(CO2) and 24 Å2(SO2) are comparable to liquid density values. The isosteric heat of adsorption of CO2is constant for 0.2<θ<0.4 and is lower than the latent heat of condensation. For SO2, the two are practically identical up to the monolayer. Entropy calculations show ‘supermobility’ in the

ISSN:0018-019X    

DOI:10.1002/hlca.19720550114

出版商:WILEY‐VCH Verlag GmbH    

年代:1972

数据来源: WILEY

摘要:

AbstractPulse radiolysis of oxygen‐saturated bromobenzene yields a transient absorption with λmax= 480 nm at pulse end, which is identified as due to the BrO2‐radical. To confirm this assignment the same radical was produced by flash photolysis of a Br2/O2‐gas mixture and by chemical synthesis at low temperature. The absorption spectra of these BrO2‐samples present a maximum between 480 and 380 nm dependent on the solvent. The influence of complex‐formation on this absorption band is discussed. The ESR.‐spectrum of chemically synthesized

ISSN:0018-019X    

DOI:10.1002/hlca.19720550115

出版商:WILEY‐VCH Verlag GmbH    

年代:1972

数据来源: WILEY

摘要:

AbstractAcetylene reacts smoothly with tribenzylaluminium both by ‘normal’ addition to the AlC bond and by aromatic substitution inorthoposition; further addition reactions can take

ISSN:0018-019X    

DOI:10.1002/hlca.19720550116

出版商:WILEY‐VCH Verlag GmbH    

年代:1972

数据来源: WILEY

摘要:

AbstractSome features in the history and development of theX‐ray crystallography of organic molecules are described, from the simple but fundamental structures of the 1920's and 1930's to the complex biological structures of today. The most important developments were probably the introduction of phase determining methods based on the use of heavy atoms, and the invention of the electronic digital compute

ISSN:0018-019X    

DOI:10.1002/hlca.19720550117

出版商:WILEY‐VCH Verlag GmbH    

年代:1972

数据来源: WILEY

摘要:

AbstractThe diazotization of 2‐chloro‐4,6‐dinitroaniline, 2,6‐dichloro‐4‐nitroaniline, and 4‐nitroaniline in concentrated sulfuric acid is very strongly catalysed by water. At a given water concentration the reaction rates of these amines are in the ratio 50/20/1. The relation between the bimolecular rate constantskand the acidity functionH0is very simple, the plots of logkversusH0being linear with

ISSN:0018-019X    

DOI:10.1002/hlca.19720550118

出版商:WILEY‐VCH Verlag GmbH    

年代:1972

数据来源: WILEY

摘要:

AbstractThe complexation of the shift reagent tris‐(dipivalomethanato)‐europium with pyridine in deuteriochloroform has been studied by means of1H‐NMR. Shift parametersS= 28.0, 9.9, and 9.2 ppm respectively for pyridine protons 2, 3 and 4 are obtained. The results indicate that the shift reagent complexes a single pyridine molecule with an association constantK1>100 mo

ISSN:0018-019X    

DOI:10.1002/hlca.19720550119

出版商:WILEY‐VCH Verlag GmbH    

年代:1972

数据来源: WILEY

摘要:

Abstract4‐Methyl‐azobenzol‐Derivate ohne elektronenanziehende Substituenten und ohne Gruppen, die mit Basen Salze bilden, werden mit Anilen aromatischer Aldehyde in Dimethylformamid in Gegenwart von Kaliumhydroxid oder Kalium‐t‐butylat zu Styryl‐Derivaten umgesetzt («Anil‐Synthese»). Bei Anwesenheit von elektronenanziehenden Gruppen dagegen werden die 4‐Methyl‐azobenzol‐Derivate zu symmetrischen Dibenzyl‐ bzw. Stilben‐Derivaten oxydiert. Mit 4‐Benzyl‐azobenzol‐Derivaten gelingt die Anil‐Synthese nur bei gleichzeitiger Anwesenheit von Elektronen‐Dona

ISSN:0018-019X    

DOI:10.1002/hlca.19720550120

出版商:WILEY‐VCH Verlag GmbH    

年代:1972

数据来源: WILEY

摘要:

Abstract4‐(Benzyl‐alkyl‐amino)‐4′‐methyl‐azobenzole ergeben mit Anilen aromatischer Aldehyde in Dimethylformamid in Gegenwart von Kaliumhydroxid bei 40–45° Styrylderivate; bei höheren Temperaturen kann als Folge‐Reaktion deren Benzylalkylaminogruppe sich unter Oxydation zu einer N‐Alkyl‐benzimidoyl‐Gruppe umlagern, die durch anschliessende saure Hydrolyse in

ISSN:0018-019X    

DOI:10.1002/hlca.19720550121

出版商:WILEY‐VCH Verlag GmbH    

年代:1972

数据来源: WILEY