Ozonolysis of 1-Methylcyclohexanol

The kinetic features and composition of products of 1-methylcyclohexanol ozonolysis were studied.     

The photoenol tautomer of 5-methyl-1, 4-naphthoquinone

Irradiation of pale yellow 5-methyl-1, 4-naphthoquinone ( 1 , Scheme 1) yields the blue photoenol 4-hydroxy-5-methylidene-1(5H)-naphthalenone (2) which is stable at 77 K. At room temperature the enol retautomerizes to starting material, the reaction rate being strongly dependent on the hydrogen-bond-acceptor basicity of the solvent. The enol is trapped in the presence of acid by protonation at the remaining carbonyl oxygen atom and subsequent electrophilic reaction of the exocylclic methylene group.     

Secoandrostansäuren als enantiomere prostaglandin-analoga—I : 4- propyl-3,4-seco-androstan-3-säuren

Starting with 4-propyltestosterone syntheses of the enantiomeric tetrahydro-PGA₁ analogue 60 and its epimer 58 are described. Besides the isomer 56 the deoxy compound 28 as well as its noracid 35 were prepared as compounds closely related to 60. A key intermediate was the unsaturated acid 20.     

X-Ray Diffraction Study of the Smectic I, F, J and G Phases of—4—2-Methy1Butyl Phenyl 4-n-Octybiphenyl-4-Carboxylate

The smectic I, F, J and G phases of the chiral ferroelectric compound (+)-(4-(2'-methylbutyl)phenyl 4'-n-octylbiphenyl-4-carboxylate) (+ 2M4P8BC) were studied by means of optical microscopy and X-ray diffraction. The free-standing film method was used. The films were additionally ordered with a d. c. electric field and true monodomain samples were prepared and examined.     

Ozonolysis of Alkenes and Studies of Reactions of Polyfunctional Compounds: LXV. Ozonolysis of Perfluoro-1-octene in Freon-113

Ozonization of perfluoro-1-octene in Freon-113 yields the corresponding ozonide whose catalytic hydrogenation over Pd/C or hydride reduction leads to formation of perfluoroheptanoic acid; the reduction with lithium aluminum hydride gives 2,2,3,3,4,4,5,5,6,6,7,7,7-tridecafluoro-1-heptanol. Ozonization of perfluoro-1-octene in Freon-113 containing excess (3 equiv) alcohol affords the corresponding perfluoroheptanoic acid ester.     

Rearrangement ions—I: Mass spectrum of thionylaniline-1-13C

Recent publications^1,2 concerning the mechanism for the electron-impact induced loss of carbon monoxide from the molecular ion of thionylaniline have led to an examination of thionylaniline-1-¹³C. The results show that the C-1 carbon atom is not lost in this process, but only suggest the loss of the C-2 carbon atom.     

Anwendung von ionenaustauschverfahren zur bestimmung von spurenelementen in natürlichen wässern—I: Kobalt

Two methods are described for the determination of cobat lin natural waters. In the first the sample is acidified with HCl, then ascorbic acid and potassium thiocyanate are added, and the solution is run through a column of strongly basic anion-exchanger (Dowex 1-X8). The cobalt thiocyanate complex is retained on the column while other ions are washed through with a mixture of organic solvent and aqueous HCl. The cobalt is then eluted with purely aqueous 6M HCl and determined photometrically with nitroso-R salt. In the second method, (for very dirty samples) the filtered sample is taken through a multi-step evaporation procedure and then added to the column in the mixed solvent. Results are presented for many samples collected in Lower Austria.

Résumé

On décrit deux méthodes pour la détermination du cobalt dans les eaux naturelles. Dans la premiére l'échantillon est acidifié par HCl, puis on ajoute de l'acide ascorbique et du thiocyanate de potassium, et la solution est passée sur une colonne d'échangeur d'anions fortement basique (Dowex 1-X8). Le complexe de thiocyanate de cobalt est retenu sur la colonne tandis que les autres ions sont lavés avec un mélange de solvant organique et de HCl aqueux. Le cobalt est alors élué avec HCl 6M purement aqueux et dosé photométriquement avec le sel nitroso-R. Dans la seconde méthode (pour les échantillons trés sales), l'échantillon filtré est soumis à une technique d'évaporation multistades puis ajouté à la colonne dans le solvant mixte. On présente des résultats pour de nombreux échantillons prélevés en Basse-Autriche.     

Studies on conformation—I Preparation and stereochemistry of some 4-piperidinols

The reduction of a number of 4-piperidones by different methods afforded epimeric pairs of 4-piperidinols. Methods of formation, isomerization studies and the degree of adsorption on alumina indicate their conformation. The stereochemical course of the reductions is discussed.     

Massenspektrometrie von Silylpyrazolen—I: Isomere Trimethylsilylpyrazole

By a comparison of the mass spectra of mono-, bis- and tris(trimethylsilyl)pyrazole isomers, characteristic influences of the different TMS-groups are revealed. An N-TMS-group forms an ion of mass 72 in the spectrum of N-TMS-pyrazole and with more than one TMS-group present, leads to the expulsion of a neutral fragment C₃H₈Si. Decomposition of the 4-TMS-group is more facile than the others, giving rise to a small molecular ion of intensity (approx.) 5%Σ₄₀. In N-silylated pyrazoles without a 4-TMS-group, intensive elimination of HCN from the [M ? CH₃˙]⁺ ion can be assigned to an unsubstituted C-3 position. In the case of unsymmetrically substituted pyrazoles without and N-TMS-group, silylation by an N-TMS acetamide may help to identify the predominating tautomer.     

β-甲萘醌催化氧化合成技术研究进展

综述了不同原料合成K系维生素重要中间体β-甲萘醌的不同方法及相应催化氧化体系建立的研究进展。与传统工业生产工艺相比较,着重分析以β-甲基萘为原料所采用的各催化剂类别及其催化氧化合成路线的特点和不足;结合国内外催化材料使用和国内生产现状,提出环境友好绿色催化氧化合成β-甲萘醌的未来发展趋势及研究方向。     

Massenspektrometrie isomerer Diazaphenanthrene—I

The mass spectra of five diazaphenanthrenes formed by photochemical cyclodehydrogenation of styryl diazines are investigated. It is shown that fragmentation of these compounds starts almost exclusively at the heterocyclic part of the molecule and proceeds by competitive α-cleavage. From the intensity ratios of the ions [M ? H˙]⁺, [M ? HCN]⁺˙, [M ? N₂]⁺˙ and [M ? 2 HCN]⁺˙ generated in this way, each isomer can unequivocally be identified.     

Lactams—I The synthesis and acid hydrolysis of 4- and 5-substituted 1-benzyl-2-piperidone derivatives

In order to explain the difficulty in hydrolysing the lactam linkage of 1-benzyl-2-oxo-5-ethyl-4-piperidineacetic acid (XIV) under acid conditions, several model compounds such as 1-benzyl-2-piperidone (X), 1-benzyl-5-ethyl-2-piperidone (XI), 1-benzyl-4-ethyl-2-piperidone (XII) and 1-benzyl-2-oxo-4-piperidineacetic add (XIII) were prepared and their hydrolysis in boiling 6N HCl was studied. For each of the lactams, the hydrolysis was found to proceed to an equilibrium as shown in Table 1. Substituents at the 4- and 5-positions of the piperidone ring seemed to favour the ring form in the equilibrium between piperidones (X-XIV) and ω-amino acid hydrochlorides (type XV).     

Mass spectrometry in cardenolide chemistry—I

The mass spectrum of penta acetyl gitoxin is reported and discussed. This cardenolide derivative has recently been the subject of extensive metabolic study. Fragmentation processes are described which account for all of the major ions. High resolution measurements, metastable peaks and mass shifts, for the propionyl derivative, are reported to establish the validity of these proposals. A brief indication of the potential value of this technique, when combined with deuteroacetylation, to metabolic studies in this field is given, along with comments on the spectra of related compounds.     

Bicyclanes—I The halogenation of 2:2:1-bicycloheptane (norbornane)

The free-radical halogenation of norbornane gives mainly the 2-halides; exo/endo ratios depending on the nature of the halogen donor. Molecular chlorine or bromine give about 70 per cent of exo- and 20–25 per cent of endo-halides: SO₂Cl₂, CCl₄, PCl₅ and CBrCl₃ give 95 per cent of the exo-isomer. This increased stereospecificity is ascribed to the relatively lower accessibility of the intermediate 2-norbornyl radicals from the endo-side for the bulkier reagents.

A small proportion of the 7-chloride was observed in the chlorinations with Cl₂, SO₂Cl₂ and PCl₅; the bridgehead chloride (1) could not be detected.

Competitive halogenations of norbornane and cyclohexane indicate that the methylene groups in cyclohexane and in the six-membered ring of norbornane are about equally reactive towards various attacking radicals.     

High resolution mass spectrometry—I. Some substituted δ-lactones

The mass spectra of some δ-lactones substituted in various positions by methyl groups have been studied both by accurate mass measurements at high resulution and by deuterium labelling. The loss of carbon dioxide has been shown to be important only for a mono-substituted lactone. A fragmentation mode common to all the lactones studied is the elimination of the ring oxygen atom, plus the adjacent carbon atom with its substituents, as a neutral carbonyl molecule such as formaldehyde, acetaldehyde or acetone. Deuterium labelling has uncovered the existence of a rearrangement involving hydrogen transfer in an even-electron ion, and a mechanism involving a six-membered transition state is proposed for this. The bond fissions, common to all the lactones, by which the principal ions in the mass spectra arise, are summarised.     

Elimination of the 4-hydroxyl group of the alkaloids related to morphine—I

Sinomenine, an alkaloid of the Japanese plant Sinomenium acutum, was converted to the 4-phenylether by the Ullmann reaction in a good yield. The Clemmensen reduction of sinomenine-phenylether and of its derivatives gave (+)-3-methoxy-4-phenoxy-N-methyl-Δ^x-morphinan.

Hydrogenation and successive sodium-liquid ammonia reduction of (+)-3-methoxy-4-phenoxy-N-methyl-Δ^x-morphinan gave (+)-3-methoxy-N-methylmorphinan.