摘要:

AbstractA study of the ultraviolet, infrared, and nuclear magnetic resonance spectra of Δ8,9‐octahydro‐7‐quinolone (7a) and of the corresponding N‐ and O‐ethyl derivatives8and9, respectively, confirms that in cases of potential enonamine‐enolimine tautomerism the enonamine form predominates. This also applies to vinylogous amides capable of intramolecular hydrogen bonding, such as 2‐benzylaminomethylene‐ and 2‐phenylaminomethylene‐cyclohexanone,10and11, respectively. Exeptions are only observed in cases where the enolimine form is stabilized by special factors,

ISSN:0018-019X    

DOI:10.1002/hlca.19670500302

出版商:WILEY‐VCH Verlag GmbH    

年代:1967

数据来源: WILEY

摘要:

AbstractBy means of chemical degradation, N.M.R. and mass spectrometry structure II has been determined for the antibioticborrelidin.

ISSN:0018-019X    

DOI:10.1002/hlca.19670500303

出版商:WILEY‐VCH Verlag GmbH    

年代:1967

数据来源: WILEY

摘要:

AbstractAusVinca herbaceaW. K. WURDE ein neues Alkaloid, Hervin, isoliert, für das im wesentlichen auf Grund spektroskopischer Befunde die Struktur1abgeleitet wurde

ISSN:0018-019X    

DOI:10.1002/hlca.19670500304

出版商:WILEY‐VCH Verlag GmbH    

年代:1967

数据来源: WILEY

摘要:

AbstractOn heating linalool, all the four possible diastereomeric plinols are formed by way of an intramolecular Alder “ene”‐synthesis. The knowledge of their absolute configuration, shown to be2A‐2D, allows a discussion of the stereochemical course of this r

ISSN:0018-019X    

DOI:10.1002/hlca.19670500305

出版商:WILEY‐VCH Verlag GmbH    

年代:1967

数据来源: WILEY

摘要:

AbstractThe synthesis of azaprotoanemonine and three of its methylhomologs, starting from the corresponding 4‐oxo‐2‐pentenoic acids, is desc

ISSN:0018-019X    

DOI:10.1002/hlca.19670500306

出版商:WILEY‐VCH Verlag GmbH    

年代:1967

数据来源: WILEY

摘要:

AbstractVitamin B1, in chloride (1) or iodide form, decomposes thermally in the mass spectrometer mainly into 2‐methyl‐4‐amino‐5‐chloromethyl(iodomethyl)‐pyrimidine and 4‐methyl‐5‐β‐hydroxyethyl‐thiazole, and partly, by loss of HCl (HI) under cyclisation, into the base2. The mass spectrum exhibits peaks due to these products and their fragments. The mass spectra of some model c

ISSN:0018-019X    

DOI:10.1002/hlca.19670500307

出版商:WILEY‐VCH Verlag GmbH    

年代:1967

数据来源: WILEY

摘要:

AbstractThe two isomeric tetrahydropyrenes II and III have been prepared by Birch reduction of pyrene. Air oxidation of either compound yields 1,2,3‐trihydropyrenyl (1,9‐trimethylene‐phenalenyl; IV); its ESR. hyperfine structure is shown to be closely related to that of phena

ISSN:0018-019X    

DOI:10.1002/hlca.19670500308

出版商:WILEY‐VCH Verlag GmbH    

年代:1967

数据来源: WILEY

摘要:

AbstractA new device using electrically heated thermocouples for thermal micro‐analysis is described. Three examples of applications are give

ISSN:0018-019X    

DOI:10.1002/hlca.19670500309

出版商:WILEY‐VCH Verlag GmbH    

年代:1967

数据来源: WILEY

摘要:

AbstractSome simple rules for predicting the transfer of endo hydrogens in the mass spectra of norbornane carbonyl derivatives are proposed. Transfers from C‐6 to C‐2 generally occur, but are repressed if a methyl group is on C‐1. Transfers from C‐5 to C‐2 can occur, but are less favorable than 1‐3 transfers. Endo‐2‐acetylnorbornanes undergo a γ‐hydrogen transfer from C

ISSN:0018-019X    

DOI:10.1002/hlca.19670500310

出版商:WILEY‐VCH Verlag GmbH    

年代:1967

数据来源: WILEY

摘要:

AbstractBy means of the flash photolysis technique, transient absorption spectra attributed to tetramethyl‐dehydrodianthrone (TMD) in both the photochromic and triplet states have been investigated in polymethylmethacrylate matrices and in the solvent triacetin. In polymethylmethacrylate matrices and in rigid glasses of triacetin the triplet state of TMD is heavily populated. Triplet‐triplet absorption and phosphorescence measurements show that below 180°K the triplet decay follows first order kinetics with the decay constantk=11,3 ± 0,1 s−1. In incompletely solidified triacetin glass it is possible to monitor the transient absorption of the photochromic and the triplet state simultaneously. It is shown that the photochromic state1A1* is not generated via the triplet state. Therefore the authors suggest a kinetic scheme characterised by a direct singlet state ‐ photochromic state t

ISSN:0018-019X    

DOI:10.1002/hlca.19670500311

出版商:WILEY‐VCH Verlag GmbH    

年代:1967

数据来源: WILEY