A. Horeau

Method for obtaining an enantiomer containing less than 0·1% of its antipode. Determination of its maximum rotatory power

Abstract The reaction of a chiral compound R on each of enantiomers which constitute a mixture of optical purity p, is characterized by rate constants whose ratio K often may be evaluated experimentaly. The application of the formula of homocompetitive reactions allows to calculate the percentage of the mixture of the antipodes that must be consumed, the reaction leading to a new optical purity p′ (which may be 99·9%). This possibility has been checked experimentaly.

Micromethode de determination de la configuration des alcools secondaires par dedoublement cinetique. Emploi de la spectrographie de masse

Abstract An optically active secondary alcohol is treated by an equimolecular mixture of (+)-2-phenylbutyric and (−)-2-phenyl-4-d-butyric anhydrides. The configuration of the carbon atom bearing the OH group is deduced from the relative heights of peaks m/z 120 and 119 observed in the mass spectra of the resulting diastereoisomeric esters.

Conformational analyses by x-ray crystallography—II : Prelog's rule and the conformation of (−) menthyl phenylglyoxylate

Abstract The conformation of (−) menthyl p-bromophenylglyoxylate has been examined by X-ray crystallographic methods. The main features of the conformation lie in the two CO groups being approximately at right angles to one another, and the ester CO oxygen eclipsing the nearest axial H atom. Prelogs rule is discussed in the light of this result.

Configurations absolues des methylbenzhydryl, isopropylbenzhydryl et isopropylbenzylcarbinols

Resume Les configurations absolues des methylbenzhydryl, isopropylbenzhydryl et isopropylbenzylcarbinols ont etees determinees par des filiations chimiques non ambigues.