Preparation d'esters par deshydrogenation d'alcools primaires en phase liquide catalysee par l'oxyde de cuivre - observations preliminaires

Linear primary alcohols with at least 7 carbon atoms are quite quantitatively transformed in esters, by CuO, at temperatures > 170°, without air in liquid phase. Preponderant influence of carbon in position 2 is evidenced. In the same conditions lactones are obtained from diols, and benzylic alcohols undergoes, by hydride transfer, a disproportionation into toluene, benzaldehyde and water.     

Synthese d'aziridines N-non substituees par reduction de sels d'hydrazonium

Z and E N,N,N-trimethylhydrazonium iodides from α,β-unsaturated cyclohexenones are reduced in good yields into saturated aziridines or α,β-unsaturated aziridines by sodium bis (2-methoxy ethoxy) aluminium hydride. Partly hydrolysed hydride leads to reverse proportions of saturated and α,β-unsaturated aziridines.     

Reactivite des cyclopropylidenecycloalcanes - I - leur oxydation par OsO4 en presence d'oxydes d'amines

The osmium tetroxyde oxidation of cyclopropylidenecycloalkanes leads to the expected 1,2 diols, expected in the case of cyclopropylidenecyclopropane derivatives where the reaction gives a mixture of cyclohexanedione and formylcyclopropane derivatives.     

Etude quantitative par absorption optique de l'homogeneite de monocristaux d'arseniure de gallium

The optical absorption coeffient of n-type gallium arsenide is measured at many places of samples with an infrared microscope (spot of 100 × 100 μm) and variable energies for the incident light. The inhomogeneities we observed are associated with free carrier density fluctuations in heavily doped single crystals and with the impurities diffusion around dislocations in lower ones.     

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.     

Sinthese de copolymeres sequences de l'acetate de vinyle et de l'acrylate d'ethyle par telomerisation

A new two-step procedure for the synthesis of ethyl acrylate - vinyl acetate block copolymers is described : the first stage is the telomerisation of ethyl acrylate with carbon tetrachloride by redox catalysis, the second being another telomerisation of vinyl acetate, using the trichloromethyl end group of the first block as the telogen agent, with peroxydic initiation.     

Reaction de perhalostyrenes avec les organolithiens. Preparation d'aryl-1 alcynes-1 ramifies par l'intermediaire d'aryl fluoro acetylenes

Organolithium compounds react with 1-aryl 2-chloro 1,2-difluoroethylene to give derivatives of type ArCCR¹. Hydrolysis of the intermediate carbanionic species yields the corresponding α,β-difluorostyrenes.     

Forme des cristallites d'oxyde de cadmium produits par decomposition de l'hydroxyde

The structural transformation that occurs in the cadmium hydroxide decomposition reaction has the morphological and crystallographic character of a martensitic transformation. The authors predict the shape of the oxide crystallites produced during the reaction, viz., small platelets developed parallel to the (111) oxide planes. The difficulty in assessing their shape by analysis of X-ray diffraction line profiles is discussed. Electron microscope and X-ray diffraction results are presented and it is shown that the oxide crystallite shape is dependent on whether the precursor is hydroxide or carbonate.