Grégoire Chiurdoglu

Spectres IR, dans la région ν(CO), d'halogénocyclohexanones et de leurs analogues α,α′-deutériés implications conformationnelles

Abstract I.R. spectra of sixteen halogeno cyclo hexanones and α,α′ deutero derivatives have been studied in the 1700–1800 cm −1 frequency range. For some halogenoketones; namely cis 2,6-dichloro cyclo hexanone, trans 2-bromo-5-methyl cyclo hexanone, 2-bromo cyclo hexanone and 2-chloro cyclo hexanone, the observed behaviour is not the same for the hydrogenated and deuterated compound. It seems that the ν(CO) region of hydrogenated compounds is “anomalous”. For the two first compounds cited above, a Fermi resonance between fundamental ν(CO) and the fist harmonic of a low frequency band seems a good explanation. In the case of bromo- and chloro cyclo hexanone, the explanation is not clear but it remains that a conformational justification alone is insufficient to explain the ν(CO) region of the hydrogenated compounds but sufficient for the deuterated compounds.

Étude de l'effet de solvant en résonance magnétique nucléaire—I : Caféine et dérivés

Abstract The NMR spectrum of caffein shows three NCH 3 peaks. By study of solvent effect and pH effect on this spectrum, it was possible to make a correct attribution of the absorption peaks. A proof of this attribution was searched in the examination of NMR spectra of theophylline and theobromine. Two new chlorocaffeins were prepared during this work.

Preparation et attribution de configuration des cis-6-t-butyl-trans,cis- et trans,trans-2-decalols et des cis-6-t-butyl-cis,cis- et cis, trans-2-decalols. Equilibration des alcools epimeres

The synthesis of cis-6-t-butyl-cis,cis-2-decalol, cis-6-t-butyl-cis,trans- 2-decalol, cis-6-t-butyl-trans,cis-2-decalol and cis-6-t-butyl-trans,trans-2-decalol has been achieved. The condensation of 4-t-butyl-1-morpholinocyclohex-1-ene with methylvinylketone gives cis-6-t-butyl-Δ1,9-2-octalone. By specific reduction of the ethylenic bond, it is easy to obtain cis-6-t-butyl-cis-2-decalone and cis-6-t-butyl-trans-2-decalone. These ketones were reduced under various conditions to give the corresponding alcohols. By means of RMN spectra and the thermodynamic data concerning the axial-equatorial equilibrium between the two systems of epimers, the configurations were determined.

Etudes spectroscopiques de quelques dérivés halogenes du cyclohexene

Abstract Infrared, Raman and ultraviolet spectra of 1-chlorocyclohexene, 1-bromocyclohexene, 1,2-dichlorocyclohexene and 1,2-dibromocyclohexene have been recorded. Assignment of the v (C-X) stretching frequencies have been made and some of the principal absorption bands of the four derivatives have been discussed. The ultraviolet data suggest a deviation from the planarity around the double bond in the case of 1,2-dibromocyclohexene. Application of B raudes formula leads to an approximate estimate of this deviation.

Etude spectroscopique de molécules halogéneés—II: Effet de solvant sur les vibrations ν(C-Hal)☆

Abstract The solvent effect on the ν(CX) vibrations of the chloro-, bromo- and iodocyclohexanes has been studied. With the aid of the H.B.W. relation, it is possible to make correlations between the solvent effect, polarity and axial of equatorial orientation of the C-X bond. On the other hand, the use of solvents mixtures gives continuous but non linear curves in K.B.M. diagrams. This behaviour is discussed.