Jacques Augé

Improved synthesis of glycosylamines and a straightforward preparation of N-acylglycosylamines as carbohydrate-based detergents.

D-Glucose, D-galactose, lactose, cellobiose, and maltose yield quantitatively the corresponding glycosylamine when treated at 42 degrees C for 36 h with a commercial aqueous solution of ammonia in the presence of one equivalent of ammonium hydrogen carbonate. After lyophilisation, the residue (i.e., the pure glucosylamine) was dissolved in a mixture of ethanol and water, and treated with acyl chlorides to afford in a few minutes N-acylglucosylamines. Micellar properties of these amphiphilic derivatives were determined.

Hexopyranose sugars conformation revised

Literature data for the conformations of ido- and altropyranose derivatives have been reexamined in the light of the newer values recently reported (Eliel . J. Am. Chem. Soc. 104, 3635 (1982) for the conformational free energy of methyl and hydroxymethyl substituent at position 2 in tetrahydropyran. The conclusion is that these values readily explain why the D-4C1 (D-1C4) chain form is more prevalent than predicted beforehand. Cases of poor agreement between the vicinal proton-proton coupling constants and the dihedral angles in their chair form may be interpreted by mixing with the S2° skew conformation, rather than the D-1C4, (L-4C1) chair form.

Hetero Diels-Alder reaction in water. Synthesis of α-hydroxy-γ-lactones

Abstract The hetero Diels-Alder reaction of cyclopentadiene or cyclohexadiene with aqueous solution of glyoxylic acid produces α-hydroxy-γ-lactones arising from the rearrangement of the cycloadducts.

A convenient and stereoselective conversion of aldehydes into β-bromovinyloxiranes mediated by chromium(II) chloride

Abstract The monoreduction of 1,3,3-tribromopropene by chromium(II) chloride gave a chromium(III) species converting aldehydes into β-bromovinyloxiranes. The stereochemistry of this new reaction is mainly temperature dependent.

A Convenient Preparation of Bistrimethylsilylmethane

Abstract Bistrimethylsilylmethane has been prepared from chlorotrimethylsilane, dibromomethane and lithium with a 55% yield, based on chlorotrimethylsilane.

André Lubineau: a life dedicated to carbohydrate chemistry

The aim of this volume 40 of Carbohydrate Chemistry, Chemical and Biological Approaches is to illustrate how wide is the scope of carbohydrate chemistry, from synthetic methodology to chemical biology, and to acknowledge Professor Lubineaus contributions to the field.