Fluorénacènes et fluorénaphènes Synthèses dans la série des indéno-fluorènes,XIX Dérivés tétraméthylés du trans-fluorénaphène et du trans-fluorénacène

By condensation of isophthaloyldichloride resp. of terephthaloyldichloride with 4-bromo-1,2-xylene according Friedel-Crafts, followed in each case by a double cyclisation and a final reduction, the 2,3,9,10-tetramethyl-7,12-dihydro-indeno[1,2-a]fluorene resp. the 2,3,8,9-tetramethyl-6, 12-dihydro-indeno[1,2-b]fluorene are synthesized.     

Fluorénacènes et fluorénaphènes synthèses dans la série des indéno-fluorènes,XVII. Dérivés méthylés du cis-fluorénacène,du trans-fluorénacène et du trans-fluorénaphène

By condensation of the chlorides of the three 9-oxo-fluorene-2-, -3-, and -4-carboxylic acids with 4-bromo-1,2-xylene on one side, and of the chlorides of o-bromobenzoic acid, 2-bromo-4-methyl-benzoic acid and 2-bromo-4,5-dimethyl-benzoic acid with fluorene, 2-methylfluorene and 3-methylfluorene on the other side, followed by direct or indirect cyclisation and by final reduction, several new methyl derivatives of the indenofluorenes I, II and IV are synthesized.     

Fluorénacènes et fluorénaphènes Synthèses dans la série des indéno-fluorènes XIV [1] Nouvelle synthèse du trans-fluorénacène

A new synthesis of 6, 12-dihydro-indeno [1,2-b] fluorene (trans-fluorenacene) in 9 steps starting from fluorene (overall yield 24,5%) is recorded. By partial oxidation of the hydrocarbon its 6-oxo derivative is also obtained.     

Synthèse d'azido dithiényl-1,2 éthènes et éthanes

Two convenient preparations of azido-1,2-dithienylethenes are described. The synthesis of azido-1,2-dithienylethanes proceeds via metalation (n-Buli) and subsequent treatment by tosylazide of bromo-1,2-dithienyl-ethanes. The structures of the obtained derivatives were established on the basis of ¹H nmr, ir, and mass spectral data.     

Étude par rayons X de copolymères téléchéliques butadiène acide méthacrylique

The telechelic polybutadiene–methacrylic acid copolymer (Hycar CTB) containing 2 mole percent acid and neutralized (5–100%) by alkali ions, Na⁺, K⁺, and Cs⁺, has been studied by small-angle x-ray scattering. Salt groups form clusters, and the average value of the radii of gyration is approximately 8 Å; this value seems to be independent of the nature of the cation and the degree of neutralization. The existence of a low-angle maximum in the scattering intensity gives evidence of a mean distance of 80 Å between clusters in the fully neutralized sample. This distance increases slightly with a decreasing degree of neutralization. A more precise analysis of the small-angle scattering curve gives further information on the cluster structure: the ionic groups may form small bilayer disks while the polymer chains maintain a regular distance of 80 Å between the disks.     

Études sur les matières végétales volatiles. CCII. Synthèse d'aldéhyde phénylacétique à partir du styrolène

On treatment of styrolene between 30 and 40°C with performic acid, phenylglycol monoformate is produced.     

Recherches sur la stéréochimie des diènes fonctionnnels—XI: Interprétation théorique des déplacements chimiques de stéréoisomères D'éthoxybutadiènes-1,3

A theoretical analysis of the proton chemical shifts of alkoxy-1,3-diene stereoisomers is proposed. The diamagnetic contribution is calculated from π and σ theoretical indices obtained by the CNDO/2 method. This effect depends on the stereochemistry of the molecule and the charges and chemical shifts alternate in the same way. The diamagnetic part is often small compared to the experimental value, however, and the paramagnetic contribution Δδ_p is important. Δδ_p is difficult to explain with the usual models of anisotropic and electric contributions, but the results give useful information on the conformations of the molecules.     

Stéréosélectivité et régiosélectivité de la réduction des cyclopropènes-2,3 et méthylène-2 cyclopropanes fonctionalisés en position 1

Reduction of 2 cyclopropenyl esters and alcohols with lithium aluminium hydride is selective; at low temperatures (0°) the double bond is not reduced, but at higher temperatures (65°) the reduction is complete and only the cyclopropylmethanol is obtained. The reduction of the double bond is regioselective (the most stable carbanion is formed) and stereospecific (the hydride attack on the double bond occurs cis to the functional group). This stereospecificity can be explained through the initial formation of an alkoxylaluminium hydride followed by an intramolecular reduction of the double bond. Similar results have been obtained in the reduction of functionalised methylenecyclopropanes.     

Synthèse et propriétés des aroylhydrazones du benzoate d'éthyle. Synthèses d'hétéroscycles azotes

The aroylhydrazones of ethyl benzoate have been prepared in fair yield by the action of aroylhydrazines on ethyl benzimidate hydrochloride. These products give rise, quantitatively, at their melting point, to 5-aryl-2-phenyl-1,3,4-oxadiazoles, and, in the presence of hydrazine hydrate, in boiling 1-propanol to 4-amino-5-aryl-3-phenyl(4H)-1,2,4-triazoles (Yields 50%). The addition of methylmagnesium iodide to these products give aroylhydrazones of acetophenone.     

Fluorénacènes et fluorénaphènes Synthèses dans la série des indéno-fluorènes,XV [1] Méthyl-5-dihydro-10, 12-indéno [2, 1-b]fluorène

Starting from α-methylchalcone and diethyl ketone the title compound, II, has been synthesized in 6 steps (overall yield 26%). As an intermediate compound the gold yellow 10, 12-dioxoderivative of II was also obtained.