Une nouvelle synthese totale de la L(+) et de la D(-)-muscarine

L(+)-muscarine and its enantiomer have been prepared in 8 steps from D- and L-threonine respectively via the highly stereoselective iodocyclization of a γ,δ-unsaturated benzylether.     

Methode simple pour la synthese rapide et stereoselective d'enoxysilanes d'aldehydes et de cetones

A new highly regio- and stereo-selective method for the preparation of enoxysilanes, viz. treatment of Me₃SiCl, NaI, Et₃N with enolizable aldehydes and ketones is described.     

Une methode simple de synthese des phosphates terpeniques allyliques primaires et tertiaires

Alkylation of tetrabutylammonium dihydrogenophosphate by terpenic allylic sulphonium salts give the corresponding primary terpenic allylic phosphates in fair to moderate yields, without complex procedures of purification. The catalysis of the reaction by cuprous ion leads to the isolation of tertiary allylic phosphates.     

Recherches sur la synthese totale des alcaloides appartenant a la serie de la carpaine et de la cassine—II : Une synthese totale de la pseudo–conhydrine de type biogenetique

The synthesis is described of t-6-propyl-3-piperidinol (dl-pseudo-conhydrine) in 3 steps from 4-4-ethylenedioxy heptanal. This reaction is similar to that recently suggested for the biosynthesis of 2-propylpiperidine (coniine).     

Une nouvelle synthese de l'ellipticine et ses analogues structuraux

Two new syntheses of the 6H-pyrido [4,3-b] carbazole system are described. The first method involves the cyclization of a (2-alkyl-skatyl)-piperidone whereas the second leads to ellipticine by the participation of the indole nucleus in the rearrangement of tertiary acetylenic alcohols in acidic medium.     

Une nouvelle methode de synthese peptidique intramoleculaire, applicable a la sarcosine, a l''aide de derives de l''aide oxalique

Two steps are postulated in a new method of intramolecular peptide synthesis using oxalic acid derivatives (Fig. 1). Both are verified with model derivatives incorporating one sarcosine residue: cyclisation of 2d into 5 (Fig. 4) and aminolysis of 5 leading to 2h (Fig. 5). Glycine, alanine and phenyl- alanine derivatives however are not cyclizised in the studied conditions (attempted acid-, by trifluoroacetic acid, and basic catalysis, by triethylamine), precluding the general use of the method.     

Nouvelle synthese de la tentoxine

We describe a new synthesis of tentoxine, cyclo(N-Me(L)Ala-(L)Leu-N-Me(ZΔ)Phe-Gly), with a direct introduction of the dehydro residue in the peptide chain. This method affords the linear tetrapeptide with a yield four times better than that given by the method of Rich.     

Recherches sur la synthese totale des alcaloides appartenant a la serie de la carpaine et de la cassine—III : Deux methodes generales de synthese des ethylenedioxy-4,4 aldehydes

4,4-ethylenedioxy aldehydes 1 can be obtained readily from 1-ethoxycarbonyl 6-methyl hept-5-en 2-one 8 by C-alkylation, followed by hydrolysis, decarboxylation, dioxolane formation and ozonolysis. Alternatively, compounds 1 can be prepared by reacting the Grignard reagent of 1-bromo 4-methyl pent-3-ene 24 with an appropriate aldehyde, followed by oxidation, dioxolane formation and ozonolysis. Compounds of type 1 should prove useful in the total synthesis of carpaine, cassine and related alkaloids.     

Phosphates - II - sur la synthese thermique de l'orthophosphate de calcium et de sodium

Résumé Etude de la synthèse thermique de l'orthophosphate de calcium et de sodium pur en partant de six mélanges adéquats. Les réactions qui ont lieu pendant le chauffage des mélanges de synthèse ont été suivies par analyse thermique (TG et ATD). La succession des réactions qui ont lieu a été établie. On a trouvé à l'aide d'une série d'analyses physico-chimiques que CaNaPO₄ peut être obtenu à partir des six mélanges étudiés.

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The thermal synthesis of pure CaNaPO₄ was investigated starting from six mixtures. The reactions during the heating of the mixtures were monitored by means of thermal analysis (TG and DTA). The sequence of reactions was established. Based on a number of physical and chemical determinations it was found that CaNaPO₄ may be obtained from all six mixtures.

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Zusammenfassung Die thermischen Synthesen der reinen Calcium- und Natrium-Orthophosphate aus sechs entsprechenden Gemischen wurden untersucht. Die sich bei dem Erhitzen der Synthesegemische abspielenden Reaktionen wurden mittels Thermoanalyse (TG und DTA) verfolgt. Die Reihenfolge der ablaufenden Reaktionen wurde bestimmt. Mittels einer Reihe von physikalisch-chemischen Analysen wurde festgestellt, daß CaNaPO₄ aus den sechs studierten Gemischen erhalten werden kann.

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CaNaPO₄ . , , ( ). . , CaNaPO₄ .

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Phosphates - I - Rev. Roum. de Chimie 11 (1966) 725.     

Etude en serie as-triazine—XIV : Etude de la synthese et de la tautomerie de phenyl-3 et phenyl-6 triazinones-5

Methylated derivatives of 3-phenyl and 6-phenyl 5-triazinones have been prepared; spectral characteristics for identification are given. Infrared, ultraviolet and NMR spectra indicate the predominance in solutions of the paraquinonoid structure for 3-phenyl and 6-phenyl 5-triazinones, but in solid state, infrared spectra show the predominance of the 5-hydroxy triazinone tautomeric structure.     

Realisation d'un derivateur permettant la mesure precise et continue de tres faibles variations de temperature

Résumé Cet article présente un dérivateur de température à très bas niveau. Il permet la mesure exacte et continue des vitesses de chauffage ou de refroidissement, de l'ambiante à 900°C avec un seuil de détection de 30°C. s^–1. Cet appareil peut être utilisé pour faire de l'analyse thermique dérivée ou comme générateur de rampes linéaires.

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A very low level temperature derivative apparatus is described. It is able to give a true and continuous measurement of heating or cooling rate from room temperature up to 900° with a detection threshold as low as 30°Cs^–1. This apparatus can be used for derivative thermal analysis and as slope temperature generator.

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Zusammenfassung Ein Derivativgerät mit sehr niedrigem Temperaturniveau wird beschrieben. Es ermöglicht eine wahre und kontinuirliche Messung der Aufheiz- und Abkühlgeschwindigkeit von Raumtemperatur bis zu 900°C mit einer Nachweisschwelle von weniger als 30°C s^–1. Dieses Gerät kann zur derivativen Thermoanalyse und als Neigungstemperaturgenerator eingesetzt werden.

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. , 900° 30 °C. ^–1. , .

     

Contribution a la synthese de prostaglandines

A new general method for grafting the β chain of natural Prostaglandins and homologs is proposed.     

Etude de la synthese des zeolites 4A et HS a partir de produits naturels

The crystallization of the zeolite HS was studied during the synthesis of the zeolite 4A using several raw materials like diatomite, kaolin and bentonite. First, these three materials were activated mainly by melting in the presence of caustic soda. The comparison with the pure reagents (solution of sodium silicate and sodium aluminate) as a reference allowed to deduce that an appearance of the zeolite HS during the synthesis is observed with most of the raw materials. Its formation takes place when the concentration of aluminium decreases below the value corresponding to the pure products in the liquid phase. This situation takes place when the reactant gel is heterogeneous, which is characteristic of all the raw materials studied. This seems to be the reason for the formation of zeolite HS.