La transformation d'indolines en indoles et d'autres reactions apparentees

Phenylseleninic anhydride reacts rapidly with indolines at 0° to give, when the β-position is substituted, the corresponding indoles. When the β-position is unsubstituted β-phenylseleno- indoles are formed. These are readily reduced by nickel boride to the parent indole. Tetrahyrdroisoquinoline is dehydrogenated with comparable ease. Phenylseleninic acid is also an efficient agent for these dehydrogenations.     

Influence des interactions attractives non liees sur les stabilites relatives d'ethers et d'acetates d'enol renfermant un groupe styryle

The measure of relative stabilities of β-alcoxystyrene isomers I: C₆H₅-CHCH-OR shows that the trans compound is the most stable when RCH₃ and C₂H₅ and the cis compound is the most stable when Ri-C₃H₇ and t-C₄H₉. The orientation of the OR group can be determined by RMN ¹³C. The stabilities of these molecules are discussed in terms of non bounded attractive interactions. This interpretation is confirmed by the measure of relative stabilities of α-methyl β-alcoxy (and acetoxy)-styrene isomers II: C₆H₅-C(CH3)CH-OR. (RCH₃, C₂H₅ et COCH₃).     

Mise en évidence d'un désordre statistique dans les structures chalcogénoiodures d'étain et d'antimoine

The crystal structures of Sn₂SbX₂I₃, with X = S or Se, and Sn₃SbSe₂I₅ are characterized by a statistical disorder of part of the [Sb] and [Sb, Sn] sites. All these crystal structures are built up from infinite ribbons (Sn₂X₄)_n of SnX₅ pyramids where X = ((S, Se) and I). The ribbons are weakly linked through Sn … I interactions to give infinite sheets. Between sheets are located [Sb] or [Sb, Sn] atoms in twinned sites.     

Reaction d'un thiolate de molybdene sur l'hexafluorobutyne

Bis(methyl)disulphide and the organometallic compound {(Cp)Mo(CO)₃}₂ in low oxidation state under photolysis give especially with the hexa-fluorobut-2 yne a 18-electron olefin complexe {(Cp)Mo(CO)₃(CF₃C₂CF₃SCH₃)}. The new compounds are reported and the reaction discussed.     

Action d'organozinciques α-ethyleniques sur le chloroformiate d'ethyle: preparation d'esters β-ethyleniques

The reaction of organozinc compounds RCHCHCH₂ZnBr with ethyl chloroformate gives β-ethylenic esters CH₂CHCH(R)COOC₂H₅ in good yields; these esters are readily converted to the corresponding α-ethylenic esters on treatment with piperidine.     

Synthese d'isoquinoleines F-alkyl substituees

In this paper we report preparation of isoquinolines F-alkyl substituted in $\text{1}$ position by R_F chains such as CF₃, C₃F₇, C₅F₁₁, C₇F₁₅. These compounds are obtained by catalytic deshydrogenation of the F-alkyl-1 dihydro-3,4 isoquinolines which are prepared by cyclodeshydratation of the N-(phenyl-2 ethyl) F-amides and N- (phenyl-2 propyl) F-amides. These last compounds are obtained the N-allyl F-amides by Friedel-Crafts type reaction.The preparations as a whole yield 26 new F-alkyl compounds.     

Synthese d'un nouveau monomere hydrofluorocarboxylique le difluoro-2,2-butene-3-oate d'ethyle

The reaction of bromine with chlorotrifluoroethylene yields an addition product BrCF₂CFClBr, which can be further transformed into BrCF₂COOC₂H₅ by hydrolysis with oleum and esterification. The mono adduct ester, BrCH₂CH₂CF₂COOC₂H₅, is selectively obtained by ethylene telomerization in the presence of a radical initiator and ethyl bromodifluoroacetate as telogen; side-addition of two ethylene molecules cannot be completely avoided. The ester was dehydrobrominated with sodium ethanolate, yielding ethyl 2,2 difluoro 3-butenoate, CH₂CH-CF₂COOC₂H₅     

Rearrangement d'hydroperoxy-3 indolines issues de la photo-oxygenation d'indoles en milieu reducteur

Trapping by KBH₄ of intermediates formed in the reaction of N-methylindoles with singlet oxygen leads partially to 3-hydroperoxyindolines which undergo in basic methanol an unusual rearrangement to 6-methoxy N-methylindoles.     

Spectres de vibration et structure d'un cristal d'amidogallate de sodium

Raman spectra (4000-150 cm^?1) of a single crystal of NaGa(NH₂)₄ and infrared spectra (4000-200 cm^?1 ) of a polycrystalline sample have been studied at different temperatures. An assignment of the bands is given. The spectra are discussed assuming S₄ and T_d point group symmetry of the Ga(NH₂)^?₄ ion at low temperature and at room temperature respectively. Metal-ligand and N-H stretching frequencies are compared to those of some other amido metalates.     

Synthese nouvelle d'allylcetones par voie organosilicique

In the presence of a Lewis acid (AlCl₃, InCl₃, GaCl₃), acyl chlorides react with allyltrimethylsilane to give the corresponding allyl ketones, CH₂CHCH₂COR, in good yields.Substituted allylsilanes, synthesized by 1,4-disilylation of conjugated dienes, give a similar reaction. The electrophilic substitution of SiMe₃ by a COR group occurs with allylic rearrangement and therefore silylated β,γ-ethylenic ketones,

, are obtained. In most cases the allylic ketones prepared isomerize easily to the corresponding conjugated ketones; ketones having the formula CH₂CHCH₂COR lead uniquely to the trans-,propenylketones, MeCHCHCOR.     

Structure d'un nouvel heteroside d'isoflavone: le sarothamnoside

The structure of sarothamnoside (genistein 7,4′-di-O-[4-O-β-D-glucopyranosyl-β-D-apiofuranoside]), a new isoflavone glycoside from $\text{Sarothamnus scoparius}$ and $\text{S}$, patens, has been established by spectral analysis, mainly ₁₃C NMR.     

Telomeres photoreticulables—3. Synthèse de telomeres photoreticulables a partir du cinnamate d'allyle et de l'acetate d'allyle

Photocrosslinkable telomers cannot be prepared by the direct telomerisation of allyl cinnamate. However, such materials can be prepared by reaction of cinnamoyl chloride with hydrolysed telomers of allyl acetate. Transfer constants of the three telogens, (H-P(0)(OEt)₂, CCl₂HCO₂CH₃ and CCl₃CO₂CH₃) towards allyl acetate were determined also.     

Synthése d'époxydes et d'éthers glycidiques á chaîne chlorofluorée

Epoxides of general formula

(II, V) (R_F,Cl = Cl ; CF₃ ; Cl(CFClCF₂)_n?) are prepared from chlorohydrines R_F,ClCCl₂CH₂CHClCH₂OH (I).These chlorhydrines are monoadducts of carbon tetrachloride 1,1,1 trichlorotrifluoroethane, telomers Cl(CFClCF₂)_nCCl₃, with allyl alcohol.Reactions of these epoxides with lithium aluminium hydride and/or sulfuric acid lead to corresponding secondary alcohols and/or diols. Glycidyl ethers of (I) and (II,n) with epichlorhydrin could not be obtained. However, epichlorhydrin reacts with the more acidic chlorofluorinated alcohol CFCl₂CF₂CH₂OH. Thus, the glycidyl ether

is prepared.     

Mise au point d'un radiopolarographe

Radioactivity measurements of an amalgamated element at DME allow polarographic studies in conditions that are impossible to approach with current methods. An automatic radiopolarograph is presented which gives more definite waves so allowing better exploitation of results than previously. Effectively, the tests with manganese and europium reported in another article, show a standard dispersion of experimental points of 3% and residual activity before the wave of 3±2% compared with diffusion activity A_d. So with solutions of tracer scale elements, in consideration of experimental errors, heights of diffusion plateaus are determined to ±5%.     

Synthese d'acides perfluores de hauts poids moleculaires

Perfluorinated olefins of general formula CF₃(CF₂)_pCFCF(CF₂)_mCF₃ (3 ? m + p ? 25) are oxidized by potassium permanganate or ruthenium tetroxide. The linear high molecular weight perfluorinated carboxylic acids so obtained are characterized by ¹⁹F N.M.R. spectroscopy.     

Reactivite des gem-dibromocyclopropanes. III (1) : Obtention d'oximes et d'amines α-alleniques

Gem-dibromocyclopropanic oximes are reduced by organolithium derivatives in allenic oximes and by AlLiH₄-AlCl₃ in amines.In one case a 1-hydroxypyrrole is produced.     

Structure des solutions d'ions fluorure dans le chlorure d'hydrogene liquide

The infrared and isotropic and anisotropic Raman spectra of solutions of tetraethyl-ammonium fluoride at various concentrations in liquid hydrogen chloride are recorded and analyzed to elucidate the structure of the solvation aggregates surrounding the fluoride anions.The experimental results indicate that, even in the liquid state, the structure surrounding the fluoride ions is relatively ordered. The solvation number was determined as n = 4.Using a recent method (J. Chem. Phys., 1979), the radius of the first sphere of solvation was evaluated and gives a distance r_Cl-H?F = 3.1 Å.     

Equilibre entre conformation a double liaison CO ou CC eclipsee et conformation a double liaison decalee de ⋍ 60° par rapport a l'eclipse: etude comparative par spectroscopie ir d'un carbure,d'un amide,d'un aldehyde et d'une cetone

The infrared v_CO band of the ketone MeCOCH₂C(Me)₃ displays a splitting with two maxima whose components are attributed to two rotamers. The geometries of these rotamers are calculated by an a priori vibrational analysis.     

Transpositions thermiques de derives d'α-pinene

Novel thermal transformations of (+)-pin-2-en-9-al 1 and (+)-9-methyl-pin-2-en-9-one 3 by [3,3] sigmatropic mechanism to allyl vinyl ethers 2 and 4 are described. The ether 4 may undergo further rearrangement in an acid-catalysed step to the (-)-2.6-dimethylbicyclo[3.3.1]non-6-en-2ones (5 and 5'). Formation of the bicyclic ketones (+)-5 and 5' of opposite absolute configuration occurs by [3,3] sigmatropic rearrangement of the trimethylsilyl enol ether of 3 and hydrolysis. The proposed mechanism is confirmed by studying the deuterated ketone d₃^?3.     

Preparation d'olefines trisubstituees bifonctionnelles par voie photochimique

∝-methyl ∝-functionalized (CO₂CH₃, CN, CH₂OH and CH₂Cl) cyclopentanones $\text{2}$ when irradiated by UV light give title compounds : 5-substituted 4-hexen 1-al $\text{4}$ as a mixture of E and Z isomers. A comparison of the photochemical behaviour of this cyclopentanones and a simple and efficient chemical transformation of the isomers Z in the more demanded isomers $\text{4}$ E are described.