Transposition de neber en série tétrahydropyrannone

The Neber rearrangement applied to the oxime tosylates of the 4- and 3-tetrahydropyranones gives the α-aminoacetals 5 and 20 , as well as 3-amino-4,4-diethoxy and 2-amino-3,3-diethoxy-tetrahydropyranes. The hydrolysis of the former gives the pyrazine 6 and the latter gives the aminoketone 21. On the other hand the aminoacetal 5 allows one to obtain the 4-acetoxy-3-trimethylammonium tetrahydropyran iodide ( 12 ) with a preferential cis axial acetoxy equatorial trimethylammonium conformation. The oxime tosylate of the 3-tetrahydropyranone readily undergoes the Beckman rearrangement into lactam 18 whose open chain product is the (3-aminopropoxy)acetic acid ( 19 ).     

Alcoylation d'acridanone-9. Premiers exemples de O-alcoylation dans cette série de composés

The results of nucleophilic substitution of the 2-methoxy-9-acridone are discussed in terms of competition between both ionic sites N^? and O^?, of the molecule. They are the first examples of O-alkylation of substituted 9-acridone.     

Thiényl- et séléniénylthiocyanates et sélénocyanates. 4. Synthèses de thiéno[2,3-d]thiazoles,de thiéno[2,3-e]thiazines et de quelques analogues sélénophéniques

Nucleophilic aromatic substitution of 3-bromo-2nitrothiophene and selenophene by thiocyanate and selenocyanate ions in dimethylsulfoxide yields 3-thienyl-and 3-selenienylthicoyanates and selenocyanates. After reduction of the nitro group, the amino derivatives undergo cyclizatrion to thieno[2,3-d]thiazoles and seleno [2,3-d]thiazoles. Also, 4H-2,3-dihydro-3-oxothieno[2,3-e]1,4-thiazine and its selenophene analog have been obtained.     

Contribution à l'étude de la réaction de Birch en séries isoquinoléique et diaza-8,13 stéroïdique

The hydrogenation of isoquinolines following the Birch procedure was studied. We have found the conditions to obtain di or tetra hydrogenation of the homocycle. This was applied to a derivate of the 8,13-diazaestrone and we can point out the necessity of a piperidine-like amine function. this work led up to the synthesis of 8,13-diaza-19-norandrostane-3-one and 8,13-diaza-19-norandrost-4-ene-3-one with “natural” configuration.     

Etude de la séparation de traces de mercure ionique par adsorption,en milieu aqueux,sur verre sodocalcique. Application à la séparation Hg2+-organomercuriels

The separation conditions of traces of ionic mercury from aqueous solution on microbeads of soda lime are studied theoretically and established experimentally. The formation of a stable complex of the ion with ethylene diamine allows to operate at pH 7–8. The efficiency of the exchange is close to 96%. The methods allows the separation and essay of ionic mercury in presence of various organomercuric compounds.     

Recherches dans la série des cyclitols XXXVII Etude par spectrométrie de masse

Low resolution mass spectra of cyclohexane-triols, -tetrols, -pentols and -hexols and of some of their deuterium labelled derivatives have been measured. The results indicate that for some geometrical isomers quantitative differences between ion intensities are significant, allowing to deduce the stereochemistry of the molecule from its mass spectrum. In all these compounds the electron impact induced elimination of water occurs mainly by interaction between OH groups. There is a correlation between the relative abundance of (M – H₂O)⁺ and (M ?2 H₂O)⁺ ions and the number of axial hydroxyls in the more stable conformation of the molecule. Difficulties encountered in deducing fragmentation patterns, and determination of number and position of deuterium atoms in the molecule of ms-inositol are discussed.     

Oxydation allylique sélective en chimie des sucres au moyen du réactif de Fétizon. Note de laboratoire

D -glucal is selectively oxidised to the corresponding enone with a 60–80% yield by Fétizon's reagent (Ag₂CO₃-celite).     

Etudes des sélénophènes mono et bisubstitués par Résonance Magnétique de 1H et de 13C

Proton and carbon magnetic resonance spectra of mono-and disubstituted selenophenes are investigated. The proton chemical shifts are discussed in terms of magnetic anisotropy and electric field effects of the substituents, with a view to studying the conformational equilibrium of the carbonyl group. π Electronic charges, computed by the PPP method, are correlated with the proton and carbon chemical shifts. The coupling constants between ¹³C and ¹H (1, 2 or 3 bonds) and ¹³C? ⁷⁷Se are shown to be good structural parameters and a set of substituent additivity constants is calculated.     

Etude par spectrométrie de masse d'une série d'alcanediphtalimides-α,ω

Mass spectrometric study of a series of alkane-α,ω-diphthalimides Alkane-α,ω-diphthalimides with three to seven aliphatic C-atoms were synthesized and their mass spectral behaviour investigated in detail with the aid of the deuteriated derivatives of hexane-1,6-diphthalimide. Besides the expected hydrogen rearrangements, an interesting skeletal rearrangement has been observed.     

Recherches en série azabenzodiazépine. VI—etude en spectrométrie de masse de pyrazolo [3,4-b]diazépines-1,4

The mass spectra of 21 1,4-pyrazolo[3,4-b]diazepines are reported and analysed. Each of the five structures of the diazepine ring present is characterized by a particular group of fragmentations; among them one is common to all the compounds under study: the cleavage of C-5? C-6 and C-7? N-8 bonds leading to pyrazoloimidazoles ions.     

Recherches dans la série de la quinoléine: Préparation et oxydation du chlorhydrate de (1-quinoléinio)acétate

Reaction of quinoline with chloroacetic acid yields N-carboxymethyl-quinolinium chloride ( 1 ) (75%), which is oxidised by K₃Fe(CN)₆ in the presence of a base to N-carboxymethyl- 2 -quinolone ( 2 ) (70%). If 2 is heated in pure form at 300°, 1,3-Bis(2-quinolon-1-yl)acetone ( 4 ) (43%) is obtained; the expected N-methyl-2-quinolone ( 5 ) is formed by decarboxylation of 2 in benzyl benzoate at 275° (34%).     

Effets de substituant,d'hétéroatome et de solvant sur les cinétiques de décoloration thermique et les spectres d'absorption de photomérocyanines en série spiro[indoline-oxazine]

Substituent, Heteroatom, and Solvent Effects on the Thermal-Bleaching Kinetics and Absorption Spectra of Photomerocyanines Issued from Spiro[indoline-oxazines] Quantitative information useful for the development of new photochromic systems is obtained from the study of heteroatom and substituent effects on the thermal-bleaching kinetics and the absorption spectra of the photomerocyanines issued from spiro[indoline-oxazines]. The effect on photochromic properties of the presence of N-atoms either in the dimethine bridge or in the aromatic rings has been investigated through the comparison of spiro[indoline-naphthopyrans] C with spiro[indoline-naphthoxazines] A and with spiro[indoline-quinolinoxazines] B . Besides the occurrence of biexponential thermal-bleaching kinetics in non-polar solvents is observed: a tentative explanation for this observation is given which involves the formation, in either sequential or parallel steps, of energetically distinct stereoisomers of the opened form.     

Groupes de départ inhabituels lors de cyclisations dans la série des quinoxalines,II [1]

Quinoxaline-3-ketones substituted by different groups in position 2 (I) are easily cyclized by hydroxylamine and phenylhydrazine to form isoxazolo[4, 5-b] quinoxalines (II) and pyrazolo [3, 4-b] quinoxalines (III) respectively. The reactions proceed via the oximes resp. phenylhydrazones. Groups displaced are not only the customary leaving groups of aromatic S_N2 reactions (halogens, OH), but likewise H, COOH, CONH₂, CO-Ar, and, less easily, benzyl groups; methyl and phenyl groups were not displaced. The displacement of hydride ion in the presence of excess of hydroxylamine resp. phenylhydrazine is explained in terms of an extension of the theory of osazone formation.     

Sur la synthèse de quelques furochromènes,analogues pharmacochimiques de la xanthylétine et de la séseline

Some furochromenes substituted at the 2-position by an electron-attracting group were obtained starting from ortho-hydroxyformyl derivatives of 2,2-dimethyl-2H-chromene following various processes which are indicated. These new furochromenes are pharmacochemical analogues of some natural pyranocoumarins, and as such they are potential photosensitizers.