摘要:

Synthesis ad Structure of Zinc Complexes of 2‐Amino‐1‐azetinesThe 2‐dimethylamino‐3,3‐dimethyl‐1‐azetines7aand7bhave been synthesized in analogy to the procedure reported byGhosez et al.[1] (Scheme). The crystal structure of 1‐benzhydryl‐azetidindimethyliminium chloride5a, a precursor of azetine7a, has been established by X‐ray diffraction analysis. Treatment of azetines7aand7bwith ZnBr2in CH2Cl2/MeCN yielded tetrahedral bis (azetine)dibromozinc complexes8aand8b, respectively (Scheme 2). The molecular structure of8ahas been determined by X‐ray d

ISSN:0018-019X    

DOI:10.1002/hlca.19840670402

出版商:WILEY‐VCH Verlag GmbH    

年代:1984

数据来源: WILEY

摘要:

AbstractThe radical cations and the radical of 1,2‐bis(phenalen‐1‐ylidene)ethane (1), 1,2‐bis(phenalen‐1‐ylidene)ethene (2) and pentaleno[1,2,3‐cd: 4,5,6‐c′d′]diphenalene (3) have been characterized by ESR and ENDOR spectroscopy. The ease of formation of these radical ions and their π‐spin distributions are interpreted in terms of a simple model correlates the frontier orbitals of1, 2and3with the nonbonding MO's of tw

ISSN:0018-019X    

DOI:10.1002/hlca.19840670403

出版商:WILEY‐VCH Verlag GmbH    

年代:1984

数据来源: WILEY

摘要:

AbstractThe synthesis of 1‐(2‐propynyl)pyridinium salts3described. Compounds3react with a second pyridine molecule, in the presence of the corresponding hydrochloride, to form products of type4, Certain bases cause the 1‐(2‐propynyl)pyridinium salts3to rearrange into 1‐propadienylpyridinium salts.5. Diethylamine converts compounds3into 1‐acetonylpyridinium salts8. Moreover, treatment of3or5with sodium methoxide gives enol ether sof type 9, which can be hydrolyzed to teh ketones8. Addition of bromine to some of teh unsaturated compounds is al

ISSN:0018-019X    

DOI:10.1002/hlca.19840670404

出版商:WILEY‐VCH Verlag GmbH    

年代:1984

数据来源: WILEY

摘要:

AbstractThe enantioselective synthesis of (+)‐ and (−)‐cis‐2‐methyl‐4‐propyl‐1,3‐oxathine8and9form (E)‐2‐hezen‐1‐ol (1) as common starting material is described. The two enantiomeric forms exhibit differen

ISSN:0018-019X    

DOI:10.1002/hlca.19840670405

出版商:WILEY‐VCH Verlag GmbH    

年代:1984

数据来源: WILEY

摘要:

AbstractIR‐spectroscopic investigations of light‐induced rearrangement reactions of nitrosooxymethane (CH3ONO3), nitrosooxyethane (CH3CH2ONO) andN,N‐dimethylnitrosamine ((CH3)2NNO) in low‐temperature rare‐gas matrices have established that these molecules are transformed in two photolysis steps to the previously unknownC‐nitroso compounds nitrosomethanol (CH2(OH)(NO)), 1‐nitrosoethanol (CH3CH(OH)(NO)), and methyl(nitrosomethyl)amine CH2(NO)(NH)(CH3). Evidence for a similar rearrangement reaction has been advanced forN‐Nitrosopyrrolidinewhich is converted toC‐nitrosopyrrolidine. The matrix‐isolation technique in combination with wavelength‐selective irradiation allowed to trap and characterize an intermediate of rearrangement which revealed to be nitroxyl (HNO) complex (CH2…HNO, CH3CHO…HNO, CH3N = CH2…HNO, and). Since these findings have a close resemblance with rearrangement reactions of more complex nitrosooxy compounds, nitrosamines, or nitrosohydrazines used in organic synthesis, it is suggested that also in these reactions nitroxyl is present

ISSN:0018-019X    

DOI:10.1002/hlca.19840670406

出版商:WILEY‐VCH Verlag GmbH    

年代:1984

数据来源: WILEY

摘要:

AbstractCyanothyl‐subsituted cylohexyl cyclohexanoates, bi(cyclohexanes) and phenyl cyclohexanes were synthisized. Their mesmorphic behaviour is compared to that of the corresponding cyano derivatives. (Cyanoethyl)cyclohexyl cyclohenxanoates show mesmorphic properties in contrast to the corresponding cyano derivative. Separation of the cyano substituent from the rigid core of an anisotropic aliphatic compound by methylene groups enhances the thermodynamic stability of the mesophase. In aromatic compound, the cyanoethyl group leads to lower clearing points. These phenomena are attributed to teh influence of steric effects on the packing density and to the dependence of the clearing point on molecular associatio

ISSN:0018-019X    

DOI:10.1002/hlca.19840670407

出版商:WILEY‐VCH Verlag GmbH    

年代:1984

数据来源: WILEY

摘要:

1,2‐Epoxycarotenoids: Isolation of 1,2‐Epoxy‐1,2‐dihydrolycopene from TomatoesThe optically active, 1,2‐epoxy‐1,2‐dihydrolycopene was isolated from tomatoes. Its constitution was established by comparison with the racemic synth

ISSN:0018-019X    

DOI:10.1002/hlca.19840670408

出版商:WILEY‐VCH Verlag GmbH    

年代:1984

数据来源: WILEY

摘要:

1,2‐Epoxycarotenoids: Synthesis,1H‐NMR and CD Studies of(S)‐1,2‐Epoxy‐1,2‐dihydrolycopene and(S)‐1′,2′‐Epoxy‐1′, 2′ ‐dihydro‐γ‐caroteneThe synthesis of (S)‐1,2‐epoxy‐1,2‐dihydrolycopene ((S)‐1) and (S)‐1′, 2′ ‐epoxy‐ 1′, 2′ ‐dihydro‐γ‐carotene ((S)‐2) are described. The CD spectra of the (all‐E)‐isomers and of the isomers (7Z,S)‐1and (7′Z,S)‐2are discussed. The comparison of the CD spectra of the synthetic (S)‐1and the compound i

ISSN:0018-019X    

DOI:10.1002/hlca.19840670409

出版商:WILEY‐VCH Verlag GmbH    

年代:1984

数据来源: WILEY

摘要:

AbstractOxidative hydroboration ofexo‐ (1) andend‐Fe(CO)3(2) complexes of 5,6‐dimethylidenebicyclo[2.2.2]oct‐2‐ene are highly stereoselective and giveendo‐alcohol3andexo‐alcohol4as major products, respectively,Collinsoxidations of3and4furnish the correspondingexo‐Fe(CO)3‐complexed 5,6‐dimethylidene‐2‐bicyclo‐[2.2.2]octanone7and8. NaBH4reduction ofexo‐complexes7gives a mixture of3and isomericexo‐alcohol18, whereas reduction ofendo‐complexes8gives theendo‐alcohol,endo‐complexes19, as the sole product. The base‐catalyzed H/D exchange of7and8afford the dideuteratedexo‐complex35and the monodeuteratedendo‐complex32, respectively. Oxidative hydroborations of theexo‐(9) andendo‐Fe(CO)3(10) complexes of 5,6‐dimethylidenebicyclo[2.2.1]hept‐2‐ene give the correspondingexo‐alcohols39and40. Oxidation of39and40gives theexo‐ andendo‐complexes41and42, respectively, of 5,6‐dimethylidene‐2‐bicyclo[2.2.]heptanone. Only HexoC(3) can be exchanged in42, wheres bothH‐atoms at C(3) in41are exchangeable. Theendo‐Fe(CO)3group in8and42blocks the base‐catalyzed H/D exchange of HendoC(3), thus providing a test for the configuration of Fe(CO)3group in these systems. These studies have led to a revisio

ISSN:0018-019X    

DOI:10.1002/hlca.19840670410

出版商:WILEY‐VCH Verlag GmbH    

年代:1984

数据来源: WILEY

摘要:

AbstractNα‐L‐Iysine with a 2‐carboxy‐4, 6‐dinitrophenyl (Dncp) haptenic group on the ε‐amino function is a potent anaphylactogen in the guinea pig. We preparedNε‐Dncp‐Nα‐benzoly‐L‐Iysinamide andNε‐Dncp‐Nα‐benzoyl‐L‐lysyl‐1‐aminopropane where the carboxyl group of Iysine is blocked. Both co

ISSN:0018-019X    

DOI:10.1002/hlca.19840670411

出版商:WILEY‐VCH Verlag GmbH    

年代:1984

数据来源: WILEY