Léon Odier

The 13C-n.m.r. spectra of inositols and cyclohexanepentols: the validity of rules correlating chemical shifts with configuration

Abstract The 13 C-n.m.r. spectra of the eight diastereomeric inositols and the ten diastereomeric cyclohexanepentols have been recorded and all of the signals have been assigned by a variety of methods. The additive empirical constants used to correlate the configuration of hydroxyl groups with the 13 C-chemical shifts differ, in the latter group, from those derived for the inositols; the removal of one hydroxyl group had altered the “rules” considerably. A better correlation was found between the spectra of the cyclohexanepentols and those of the inositols derived therefrom, in each case, by the addition of an equatorial hydroxyl group.

Détermination par résonance magnétique nucléaire du degré de substitution dans les méthyl D-glucopyranosides partiellement méthylés

Abstract In order to establish a method of determination, by n.m.r., of the degree of methylation at each position in mixtures of partially methylated methyl glycopyranosides, the chemical shift for each of the ten signals due to the methyl groups of methyl 2,3,4,6-tetra-O-methyl-α- and β- D -glucopyranoside has been determined. The chemical shift for each methyl group in both anomers was obtained by selectively deuterating the other four methyl groups. Five peaks corresponding to the five methyl groups were observed for each anomer in the solvent mixture benzene-chloroform (6:1 v/v). The method was tested on the product of hydrolysis of a tri-O-methylcellulose, and the peaks observed corresponded to those for methyl groups at O-2, O-3, and O-6. Examination of the product of partial methylation of methyl β- D -glucopyranoside indicated that the degree of methylation at positions 2, 3, 4, and 6 was 86%, 40%, 28%, and 64%, respectively.

The effect of O-methylation on chemical shifts in the 1H- and 13C-n.m.r. spectra of cyclic polyols

Abstract The 1H- and 13C-n.m.r. spectra of seven inositol methyl ethers were recorded and assigned. They were classified into five types, and the effect of O-methylation on the chemical shifts of each type is discussed.

Selective deuteration over raney nickel in deuterium oxide: Methyl glycosides

Abstract The rate of protium-deuterium exchange, catalyzed by deuterated Raney nickel in deuterium oxide, in various positions in methyl glycopyranosides and furanosides has been studied. In general, the exchange process is not highly regio-selective in these compounds. However, conditions were found under which methyl β- d -fructopyranoside can be selectively labelled on C-5, methyl β- d -fructofuranoside on C-3, and methyl β- d -galactopyranoside on C-3 and C-4.

The preparation of cyclohexanepentols from inositols by deoxygenation

Abstract Several cyclohexanepentols have been synthesized from inositols by blocking all but one hydroxyl group, converting the free hydroxyl group into its S -methyl dithiocarbonate, and treating it with tributylstannane. Suitable blocking-groups are methyl, benzyl, and methylthiomethyl ethers, and acetals. One cyclohexanepentol was prepared by the reductive deamination of an aminodeoxyinositol.

Selective deuteration. The rate of protium-deuterium exchange in inositols with raney-nickel catalyst, and the effect thereon of O-methylation

Abstract The rate of protium-deuterium exchange, catalyzed by deuterated Raney nickel, on all carbon atoms of four inositols, was measured. The rate of exchange is lowered by methylation of an adjacent hydroxyl group; this effect was studied on seven isomeric, inositol methyl ethers. Correlations between the rate of exchange and the configuration, the conformation, and the site of O -methylation of the inositols have been established.

New conditions for the synthesis of scyllo-inositol starting from myo-inositol

Abstract Equilibration of myo -inositol by Raney nickel in water has been reconsidered on a preparative scale. An efficient separation of scyllo -inositol by orthoacetate derivatization of the components of the crude mixture is proposed which gives the free scyllo -inositol in good yield.

Selective deuteration over Raney nickel in deuterium oxide: 1,6-anhydrohexoses

Abstract The relative rates of protium-deuterium exchange, catalysed by deuterated Raney nickel in deuterium oxide, in various positions of 1,6-anhydrohexopyranoses and -furanoses have been studied. Conditions have been found under which 1,6-anhydro-β- D -galactopyranose may be labelled on C-3 and 1,6-anhydro-α- D -galactofuranose on C-2.

Preparation of α- and β-D-glucoseptanose pentaacetates.

The α- and β-D-glucoseptanose pentaacetates have been prepared by treatment of ethyl 1-thio-β-D-glucoseptanoside tetraacetate with mercury(II) acetate in acetic acid. The solid state structure of the β-isomer has been determined by X-ray diffraction.