摘要:

AbstractThe mixture of carquejanols obtained from carquejol of carqueja oil has been converted in ketones. The alkohols obtained respectively by hydrogenation on Pt(O2), by lithium‐aluminiumhydride reduction and byMeerwein‐Ponndorf‐Verleyreaction have been separated by vapour phase chromatography. The ketones obtained from theBeckmannoxidation of the alkohols has been identified as carquejanone and isocarquejanone by application of theAuwers‐Sk

ISSN:0018-019X    

DOI:10.1002/hlca.19700530202

出版商:WILEY‐VCH Verlag GmbH    

年代:1970

数据来源: WILEY

摘要:

AbstractThe preparation of Na4Mn14O27, 9H2O (hitherto named manganomanganite or δ‐MnO2) by oxidation of a fresh Mn(OH)2suspension in aqueous NaOH by molecular oxygen, and its probable structure are described. It is a double layer manganate (IV) structure resembling other manganates such as chalcophanite. Orthorhombic unit cell parameters are,a0= 8,54,b0= 15,39,c0= 14,26 Å. In diluted nitric acid topotactical transition to manganese (III) manganate (IV), Mn7O13.5H2O (unit cell:a0= 2,84,c0= 7,27 Å; primitively hexagonal), and by prolonged digestion to nsutite, γ‐MnO2,

ISSN:0018-019X    

DOI:10.1002/hlca.19700530203

出版商:WILEY‐VCH Verlag GmbH    

年代:1970

数据来源: WILEY

摘要:

AbstractDried leaves ofMarsdenia erecta R. Br.gave over 6% of a crude glycoside mixture, the main portion of which consisted of weakly polar material, soluble in ether or chloroform. By mild acid hydrolysis it yielded crude sugars and aglycones. The following four crist. sugars were isolated:D‐cymarose,D‐oleandrose and two bioses: pachybiose and marsectobiose (C14H24O8, new). By PC. and TLC. the presence of digitoxose, canarose, thevetose and 3‐O‐methyl‐6‐deoxyallose could be demonstrated. The crude acyl‐genin mixture contained β‐sitosteryl‐β‐D‐glucopyranoside and three highly hydroxylated pregnane derivatives: drevogenin‐P, 17 β‐marsdenin (C21H32O6, new) and marsectohexol (C21H34O6, new), all partly esterified with acetic, tiglic and benzoic acid. Five crist. acyl‐genins (A1–A5) were isolated by chromatography, but most of them still were mixtures. After alkaline hydrolysis of the crude acyl‐genins 6 acyl‐free compounds were obtained. 4 of them were identical with the above mentioned substances, the other two: 17‐iso‐drevogenin‐P and marsdenin (17 α‐marsdenin) are formed from dre

ISSN:0018-019X    

DOI:10.1002/hlca.19700530204

出版商:WILEY‐VCH Verlag GmbH    

年代:1970

数据来源: WILEY

摘要:

AbstractDie Epoxy‐Verbindung2des (−)‐α‐Copaens (1) geht bei der Behandlung mit schwachen Säuren unter molekularer Umlagerung in zwei Alkohole (3und5) der (−)‐α‐Muurolen‐Reihe über, während sich der dritte (4) vom (+)‐δ‐Cadinen ableitet. (−)‐3β‐Hydroxy‐T‐muurolol (5) ist ebenso wie der entsprechende Ketoalkohol6mit

ISSN:0018-019X    

DOI:10.1002/hlca.19700530205

出版商:WILEY‐VCH Verlag GmbH    

年代:1970

数据来源: WILEY

摘要:

AbstractThe cristalline reaction products of acetaldehyde and some of its higher straight chain homologues with one equivalent of hydrazine are shown to be 3, 6‐dialkyl‐hexahydro‐1, 2, 4, 5‐tetrazines (1) which can be oxidized to the corresponding 3, 6‐dialkyl‐1, 2, 4, 5

ISSN:0018-019X    

DOI:10.1002/hlca.19700530206

出版商:WILEY‐VCH Verlag GmbH    

年代:1970

数据来源: WILEY

摘要:

AbstractThe kinetics of the interaction between molecular oxygen and the Co2+‐complexes of the three terdentate ligands Z, N‐(2‐picolyl)‐ethylenediamine (PEN), N‐(2‐picolyl)‐oxamide (POA) and diethylenetriamine (DIEN) have been studied spectrophotometrically and using an O2specificClarkelectrode. Starting from the respective 1:1‐ and 1:2‐complexes, the binuclear species ZCoO2(OH)CoZ and Z2CoO2CoZ2are formed with each ligand. The existence of the former product shows that a minimum of three chelating nitrogen donors is sufficient to make a Co2+‐complex reactive towards O2.As derived from the empirical rate laws the same general reaction mechanism must be valid for all three systems. In the case of PEN‐ and DIEN‐complexes the oxygen adducts are metastable intermediates and formed in stoichiometric quantities. With POA irreversible formation of cobaltic species is rapid, and O2‐adducts are present in steady state concentrations only, except in

ISSN:0018-019X    

DOI:10.1002/hlca.19700530207

出版商:WILEY‐VCH Verlag GmbH    

年代:1970

数据来源: WILEY

摘要:

Abstracttrans‐Penta‐2, 4‐dienyl phenyl ether (trans‐1), on heating at 186° in a five‐fold excess of N, N‐diethylaniline, gave via a [3s, 3s] rearrangement 23% of 2‐(1‐vinyl‐allyl)‐phenol (2) and via a [5s, 5s] rearrangement 37% oftrans‐4‐(penta‐2, 4‐dienyl)‐phenol (trans‐3). The dimeric residue was formed fromtrans‐1by diene synthesis. By working at high dilution, the formation of dimeric products was kept to a minimum. The inversion of the migrating pentadienyl residue during the rearrangement oftrans‐1totrans‐3was proved by rearrangement of the methyl labelled ethertrans, trans‐4to thep‐dienyl‐phenol8(93%) (accompanied by only 7% of9).trans‐5gave thep‐phenol9quantitatively.cis‐Penta‐2, 4‐dienyl phenyl ether (cis‐1) was converted to10on heating, by a fast [1, 5s] H‐migration.The above mentioned reactions of the typetrans‐1→trans‐3show first order kinetics and are the first examples of [5s, 5s] sigmatropic rearrangements shown to go through a ten‐membered transition state. The conformation of the activated complex is discussed in the lig

ISSN:0018-019X    

DOI:10.1002/hlca.19700530208

出版商:WILEY‐VCH Verlag GmbH    

年代:1970

数据来源: WILEY

摘要:

AbstractThe solubility and the complex equilibria in the system Mn2+‐CO2‐H2O have been investigated at 25°C in solutions of the constant ionic strength 3 M (Na)ClO4. From experimental data the following values for equilibrium constants andGibbsfree energies of formation are deduced:\documentclass{article}\pagestyle{empty}\begin{document}$$ \begin{array}{*{20}c} {{\rm MnCO}_{{\rm 3}\left({{\rm ppt}{\rm .}} \right)} :{\rm log}\left[{{\rm Mn}^{{\rm 2 + }} } \right] \cdot P_{{\rm CO}_{\rm 2} } \cdot \left[{{\rm H}^{\rm + } } \right]^{ - 2} = 7.97 \pm 0,04 \quad \left({I = 3{\rm M}} \right)} \\ {\Delta G{_f}{^0}{_{298,2}} = - 194,1_1 \pm 0,03_4 {{{\rm kcal}} \mathord{\left/ {\vphantom {{{\rm kcal}} {{\rm mol}}}} \right. \kern-\nulldelimiterspace} {{\rm mol}}}} \\ {{\rm MnHCO}_{\rm 3} ^ + :{\rm log}\left[{{\rm MnHCO}_{\rm 3} ^ + } \right]\left[{{\rm Mn}^{{\rm 2 + }} } \right]^{ - 1} \left[{{\rm HCO}_{\rm 3} ^ - } \right]^{ - 1} = 0,45 \pm 0,05\quad\left({I = 3{\rm M}} \right)} \\\end{array} $$\end{document}A predominance area diagram for the system Mn2+‐H2‐CO2(g)‐H2S(g)including MnCO3(ppt.), α‐MnS and

ISSN:0018-019X    

DOI:10.1002/hlca.19700530209

出版商:WILEY‐VCH Verlag GmbH    

年代:1970

数据来源: WILEY

摘要:

AbstractProton‐NMR. spectra of amino‐ and hydroxypyrimidines including biologically important bases have been measured in four solvents: CF3COOH, CF3COOHSO2, FSO3H and FSO3HSbF5–SO2at 27° and −55°C. In CF3COOH mono‐cations are formed, whereas in FSO3H and FSO3HSbF5–SO2double protonation occurs. In each case the structures of the protonated species are derived from the chemical shifts of CH, NH and OH protons and proton‐proton spin coupling constants. A combination of the measurements described leads to a complete assignment of all proton resonances of the protonated pyrimidines. This approach is also recommended for the structural determination of h

ISSN:0018-019X    

DOI:10.1002/hlca.19700530210

出版商:WILEY‐VCH Verlag GmbH    

年代:1970

数据来源: WILEY

摘要:

AbstractDie Kinetik des Transports der adsorbierbaren Spezies bei Adsorptions‐messungen nach dem Zweielektroden‐Dünnschichtverfahren wird anhand eines linearen Diffusionsmodells untersucht. Es wird die Lösung des zugehörigen Differentialansatzes angegeben und die Beziehung zwischen den an beiden Elektroden herrschenden Flüssen diskutiert. Ein Verfahren zur Errechnung des Flusses an der Messelektrode aus Momentanwerten des Flusses an der Generatorelektrode durch Reihenentwicklung wird angeführt. Es wird nachgewiesen, dass die Existenz eines zeitlichen Grenzwerts des Integrals über den Messelektrodenfluss die Existenz eines identischen Grenzwertes des Generatorflussintegrals i

ISSN:0018-019X    

DOI:10.1002/hlca.19700530211

出版商:WILEY‐VCH Verlag GmbH    

年代:1970

数据来源: WILEY