摘要:

AbstractIrradiation of 3‐phenyl‐(4), 2‐methyl‐3‐phenyl‐(8), and 2,3‐diphenyl‐2H‐azirine (10), in benzene solution in the presence of aldehydes, yields the corresponding aryl‐3‐oxazolines. Photochemical reaction of4and10with carbon dioxide leads to the formation of 4‐phenyl‐ (15) and 2,4‐diphenyl‐3‐ox

ISSN:0018-019X    

DOI:10.1002/hlca.19720550302

出版商:WILEY‐VCH Verlag GmbH    

年代:1972

数据来源: WILEY

摘要:

AbstractIrradiation of 3‐phenyl‐2H‐azirine (2) in benzene solution with a high‐pressure mercury lamp yields 4,5‐diphenyl‐1,3‐diazabicyclo[3,1,0]hex‐3‐ene (4) and not 3‐phenylimino‐4‐phenyl‐1‐azabicyclo[2,1,0]pentane (1), as had been reported previously by others [2]. 2‐Methyl‐3‐phenyl‐2H‐azirine (3) yields on irradiation a 2:1 mixture of 2‐exo, 6‐exo‐ and 2‐exdo, 6‐exo‐dimethyl‐4,5‐diphenyl‐1,3‐diazabicyclo[3,1,0]hex‐3‐ene (2‐exo,6‐exo‐ and 2‐endo, 6‐exo‐5). Irradiation of 2,3‐diphenyl‐2H‐azirine (8) leads to the formation of 2,4,5‐triphenyl‐imidazole (9) and tetra‐phenylpyraz

ISSN:0018-019X    

DOI:10.1002/hlca.19720550303

出版商:WILEY‐VCH Verlag GmbH    

年代:1972

数据来源: WILEY

摘要:

AbstractBesides talbotine (1) three new indole alkaloids,talpinine(2),talcarpine(3) and16‐epi‐affinine(4) were isolated from the stem bark ofPleiocarpa talbotiiWernham. The structure of2was deduced by chemical degradation and by analyses of the spectra of the alkaloid and its derivatives. One of these derivatives is identical with talcarpine (3).The structures2and3are similar to that ofmacroline(14), a splitting product of the bisindole alkaloidvillalstoninefromAlstonia species. 16‐epi‐Affinine (4) was chemically correlated with the known alkaloid vobasine (19).Talpinine (2) and 16‐epi‐affinine (4) were also isolated from the root bark ofPleiocar

ISSN:0018-019X    

DOI:10.1002/hlca.19720550304

出版商:WILEY‐VCH Verlag GmbH    

年代:1972

数据来源: WILEY

摘要:

AbstractThe 1,3‐dipolar addition of acetylenedicarboxylic esters (IX and X) to 2‐methyl‐4‐phenyl‐quinazoline 3‐oxide (VIII) in benzene/methanol and benzene/ethanol, respectively, gives the esters XI and XII of 3‐amino‐3‐phenyl‐2‐(2‐acetamidophenyl)‐acrylic acid as main products and the esters XIII and XIV of 2‐methyl‐4‐phenyl‐5H‐benzo[d][1,3]diazepin‐5‐carboxylic acid as by‐products. The constitutions of XI and XII are elucidated by acid hydrolysis to the 2‐phenylindole‐3‐carboxylic esters VI and VII, respectively, and by ozonolysis of XII to give benzamide and ethylo‐acetamido‐mandelate (IV). The alkaline hydrolysis of XI or XII gives the enamine derivative XVIII, which is hydrolysed by acid to oxindole and benzoic acid. The structure elucidation of XIII and XIV is based on spectroscopic data together with thc formation of XV by alkaline hydroly

ISSN:0018-019X    

DOI:10.1002/hlca.19720550305

出版商:WILEY‐VCH Verlag GmbH    

年代:1972

数据来源: WILEY

摘要:

AbstractThe kinetics of oxygen exchange between water (H2O, D2O) and18O‐labelled bromate ion has been investigated over the range of 1.7 ≤ pH ≤ 14.3 and 20 ≤ °C ≤ 95. At 60° and ionic strengthI≃ 1.0M (NaNO3), the experimental results were consistent with the rate laws (Rin moll−1s−1):\documentclass{article}\pagestyle{empty}\begin{document}$$ R = [{\rm BrO}_{\rm 3} ^ -]\{ 1.59 \cdot 10^{ - 6} + 8.1 \cdot 10^{ - 7} [{\rm OH}^ -] + 0.122[{\rm H}^ +]^2 \} \,{\rm in}\,{\rm H}_{\rm 2} {\rm O}\,{\rm and} $$\end{document}\documentclass{article}\pagestyle{empty}\begin{document}$$ R = [{\rm BrO}_{\rm 3} ^ -]\{ 4.69 \cdot 10^{ - 7} + 4.1 \cdot 10^{ - 7} [{\rm OD}^ -] + 0.378[{\rm D}^ +]^2 \} \,{\rm in}\,{\rm D}_{\rm 2} {\rm O}. $$\end{document}From the temperature dependence of the rate constants the activation parameters ΔH≠, ΔS≠and ΔC≠were derived.In the acid‐catalysed region the form of the rate law and the direction of the solvent isotope effect were the same as previously found, but the numerical values of ΔH≠andk2H/k2Ddiffer considerably. For the spontaneous and the OH−‐catalysed exchange reactions bimolecular d

ISSN:0018-019X    

DOI:10.1002/hlca.19720550306

出版商:WILEY‐VCH Verlag GmbH    

年代:1972

数据来源: WILEY

摘要:

AbstractThe addition of phenyl(trichloromethyl)mercury to five substituted norbornenes is described, and the results compared with those obtained with bicyclo[2.2.2]oct‐2‐ene and 3,3,5,5‐tetramethylcyclopentene. The reaction proves to be useful for synthetic purposes, in that it leads usually to ring expansion. However, a possible disadvantage is that the addition step is sensitive to steric hindrance and depends on the reactivity of the double

ISSN:0018-019X    

DOI:10.1002/hlca.19720550307

出版商:WILEY‐VCH Verlag GmbH    

年代:1972

数据来源: WILEY

摘要:

AbstractThe reaction ofo‐phthalaldehyde with several aromatic nitro compounds in the presence of carbon monoxide and catalytic quantities of hexarhodium‐hexadecacarbonyl eventuated in the formation of the corresponding N‐substituted isoindolinone as the major product. A reaction mechanism has been suggested incorporating deoxygenation of the nitro compound by carbon monoxide to a nitrene intermediate and the subsequent interception of the latter byo‐phthala

ISSN:0018-019X    

DOI:10.1002/hlca.19720550308

出版商:WILEY‐VCH Verlag GmbH    

年代:1972

数据来源: WILEY

摘要:

AbstractThe conformation of 34 branched‐chain unsaturated sugars, prepared by reacting differentWittigreagents with a series of 1,2‐O‐isopropylidene‐furannosul‐3‐oses, has been studied by PMR spectroscopy. The position of each compound in the flexible conformational cycle has been established by using the known stereo‐dependence of the allylic coupling constants and checked with the other parameters of the spectra. An ‘isopropylidenic’4J2,4coupling constant, present in all compounds whose H—C(4) isendoand absent in their C(4)‐epimers has proved useful for configuration

ISSN:0018-019X    

DOI:10.1002/hlca.19720550309

出版商:WILEY‐VCH Verlag GmbH    

年代:1972

数据来源: WILEY

摘要:

AbstractIn the essential oil ofJuniperus communis L. (fruit), campholenic aldehyde and its epoxide have been identified, together with the corresponding alcohol and its acetate. This is the first time the natural occurence of 2‐(2,2,3‐trimethylcyclopent‐3‐en‐1‐yl)‐ethyl syste

ISSN:0018-019X    

DOI:10.1002/hlca.19720550310

出版商:WILEY‐VCH Verlag GmbH    

年代:1972

数据来源: WILEY

摘要:

AbstractMethylgruppen in verschiedenen Stellungen des Benzolringes von 2H‐Naphtho[1,2‐d]triazol‐2‐yl‐benzol können mit Anilen aromatischer Aldehyde in Dimethylformamid in Gegenwart von Kaliumhydroxid in Styrylgruppen übergeführt werden («Anil‐Synthese»). Der Einfluss von Substituenten in Nachbarstellung zur Methylgruppe von 2‐(p‐Tolyl)‐2H‐naphtho[1, 2‐d]triazol auf den Reaktionsablauf wird untersucht. Aus 2‐Fluor‐4‐(2H‐naphtho[1, 2‐d]‐triazol‐2‐yl)‐toluol und Anilen aromatischer Aldehyde entstehen in Dimethylformamid in Gegenwart von Kaliumhydroxid 1,2,3‐Triphenyl‐7‐(2H‐napht

ISSN:0018-019X    

DOI:10.1002/hlca.19720550311

出版商:WILEY‐VCH Verlag GmbH    

年代:1972

数据来源: WILEY