摘要:

AbstractSchiff'sche Basen des Dibenzofuran‐2‐ bzw. ‐3‐carbaldehydes mitp‐Chloranilin können mitp‐tolyl‐substituierten heterocyclischen und carbocyclischen Aromaten in Gegenwart von Dimethylformamid und Kaliumhydroxid bzw. Kalium‐t‐butylat in die entsprechenden Styryl‐Derivate übergeführt werden (« Anil‐Synthese »).Die Lage der Absorptions‐ und Fluoreszenz‐Maxima der dargestellten Grundkörper mit dem Dibenzofuran‐3‐yl‐Rest wird mit der analoger Verbindunge

ISSN:0018-019X    

DOI:10.1002/hlca.19740570402

出版商:WILEY‐VCH Verlag GmbH    

年代:1974

数据来源: WILEY

摘要:

Abstract8‐Oxabicyclo[5.1.0]octa‐2,4‐diene (1) is obtained from cycloheptatriene with commercial 40% peracetic acid. Upon catalytic and LiAlH4reduction the allylic CO‐bond in1is cleaved. Acid catalised hydrolysis leads to a mixture of all six possible isomeric cycloheptadienediols. With BF3in the absence of water isomerization to 3,5‐cycloptadienone is

ISSN:0018-019X    

DOI:10.1002/hlca.19740570403

出版商:WILEY‐VCH Verlag GmbH    

年代:1974

数据来源: WILEY

摘要:

AbstractSodium cyanide in hexamethylphosphoric triamide selectively cleaves methyl esters in the presence of ethyl esters with yields ofca.80%. The mechanism of the reaction has been investigated. It consists of nucleophilic displacement by cyanide of the carboxylate ion from the alcohol carbon atom (BAl2 mechanism).

ISSN:0018-019X    

DOI:10.1002/hlca.19740570404

出版商:WILEY‐VCH Verlag GmbH    

年代:1974

数据来源: WILEY

摘要:

AbstractThe He I photoelectron spectra ofperi‐amino and dimethylamino naphthalenes are presented. The differences in the ionization energies of the π‐bands are interpreted by separation of the perturbation of the amino substituent into an inductive destabilization and conjugative stabilization. This affords the assignment of the photoelectron bands of ionization energies below 11 eV and an estimation of the dihedral angle in theperi‐dimethylamino derivatives. The data on theperi‐amino naphthalenes indicate some angular distortion in contrast to 2‐aminon

ISSN:0018-019X    

DOI:10.1002/hlca.19740570405

出版商:WILEY‐VCH Verlag GmbH    

年代:1974

数据来源: WILEY

摘要:

AbstractA novel carbohydrate has previously been isolated from human bile as a complex glycoside of bilirubin [1]. This compound has been tentatively identified as 3‐C‐hydroxymethyl‐D‐riburonic acid. To test this structural assignment the proposed branched‐chain uronic acid was synthesized. Gas chromatographic and mass spectrometric comparison of the natural and synthetic materials indicated that the proposed structure, 3‐C‐hydroxymethyl‐D‐riburonic acid, did not apply to th

ISSN:0018-019X    

DOI:10.1002/hlca.19740570406

出版商:WILEY‐VCH Verlag GmbH    

年代:1974

数据来源: WILEY

摘要:

AbstractPoly(dimethylsilyl)benzenes have been prepared by ‘in situ’ reactions of polybromobenzenes with magnesium and dimethylchlorosilane in tetrahydrofuran. The hydrolysis of these compounds yields benzo[c][1,2,5]oxadisilo

ISSN:0018-019X    

DOI:10.1002/hlca.19740570407

出版商:WILEY‐VCH Verlag GmbH    

年代:1974

数据来源: WILEY

摘要:

AbstractThe stereochemistry of β‐fragmentation products formed in the oxidation ofcis‐andtrans‐4‐t‐butylcyclohexaanemethanol with lead tetraacetate and with lead tetraacetate‐metal chloride combinations, under various reaction conditions, has been investigated, and the results compared with those obtained, under similar conditions, in the oxidative decarboxylation ofcis‐andtrans‐4‐t‐butylcyclohexanecarboxylic acid with the same reagents. It was found that all four substrates afford, under comparable conditions, identicalcis‐transproportions of the respective fragmentation products, and that, therefore, so far as steric course is concerned, both the initial homolytic and subsequent heterolytic processes involved in the lead tetraacetate fragmentation reaction are independent of the nature and configuration of

ISSN:0018-019X    

DOI:10.1002/hlca.19740570408

出版商:WILEY‐VCH Verlag GmbH    

年代:1974

数据来源: WILEY

摘要:

AbstractThe synthesis, properties and complexation of 1‐methyl‐1,4,8,11‐tetraazacyclotetradecane (1‐MeCyclam‐14), 1,5‐dimethyl‐1,5,8,12‐tetraazacyclotetradecane (2‐MeCyclam‐14) and 1,4,8,11‐tetramethyl‐1,4,8,11‐tetraazacyclotetradecane (4‐MeCyclam‐14) are described.While the Ni2+and Cu2+complexes of 1‐MeCyclam‐14 and 2‐MeCyclam‐14 exhibit square planar geometries, 4‐MeCyclam‐14 forms Ni2+and Cu2+complexes, whose absorption spectra are best explained by assuming pentaco‐ordination of the metal ions.The complexation rate of the three N‐methyl substituted macrocycles with Cu2+and Ni2+is slower than can be accounted for by water exchange and little affected by introducing methyl groups at the nitrogens. Both results are in contrast to what is known for open chain amine ligands. A mechanism for the complexation is proposed, which also explains why the products of the reaction of 4‐MeC

ISSN:0018-019X    

DOI:10.1002/hlca.19740570409

出版商:WILEY‐VCH Verlag GmbH    

年代:1974

数据来源: WILEY

摘要:

AbstractEs wird eine einfache Darstellung von N‐Trimethylsilylmethyl‐glycin durch Hydrolyse von N‐Trimethylsilylmethyl‐glycinamid besc

ISSN:0018-019X    

DOI:10.1002/hlca.19740570410

出版商:WILEY‐VCH Verlag GmbH    

年代:1974

数据来源: WILEY

摘要:

AbstractStarting from 19‐hydroxytestosteroneacetate (1) a high yield preparation of 3‐oxo‐4,4‐dimethyl‐19‐hydroxy‐5α‐steroids (e.g.7, 9, 13and

ISSN:0018-019X    

DOI:10.1002/hlca.19740570411

出版商:WILEY‐VCH Verlag GmbH    

年代:1974

数据来源: WILEY