Patent ID: 7358346

Claim:
A process for preparing a compound of formula (I′): in which: S represents a monosaccharide or a polysaccharide of up to 20 sugar units, in pyranose and/or furanose form and of the D series, said mono- or polysaccharide having at least one hydroxyl function that is free and, optionally, one or more optionally protected amine functions, the linkage represents a linkage in the β-configuration, R represents a linear or branched, saturated or unsaturated, alkyl, perfluoroalkyl or hydrofluoroalkyl chain containing from 1 to 18 carbon atoms, a cycloalkyl, cycloperfluoroalkyl or cyclohydrofluoroalkyl ring containing from 3 to 11 carbon atoms, or a phenyl or benzyl radical, it being possible for said chain or said ring to be optionally intermpted with one or more hetero atoms chosen from oxygen, sulphur, nitrogen and silicon, and optionally substituted with at least one radical chosen from —OR′ 1 , —SR″ 1 , —NR′″ 1 R′ 2 , —COOR″ 2 , —CONHR′″ 2 , —CN, halogen, perfluoroalkyl or hydrofluoroalkyl containing from 1 to 18 carbon atoms, and/or at least one cycloalkyl radical containing from 3 to 11 carbon atoms, an aryl radical or a heterocyclic radical, optionally substituted, R′ 1 , R′ 2 , R″ 1 , R″ 2 , R′″ 1 , R′″ 2 , which may be identical or different, represent a hydrogen atom, or a radical chosen from a linear or branched, saturated or unsaturated, alkyl, hydroxyl, perfluoroalkyl and/or hydrofluoroalkyl radical containing from 1 to 30 carbon atoms, comprising reacting a compound of formula (II): in which S and R have the meaning above, in solution in a linear, branched or cyclic secondary alcohol containing from 3 to 8 carbon atoms, with a reducing agent containing: (a) a metal borohydride of formula MBH 4 in which M represents an alkaline metal, in the presence of an organic carboxylic or suiphonic acid containing from 1 to 10 carbon atoms, or (b) a reactive species or complex formed by the association of a metal borohydride with an organic acid and, optionally, a secondary alcohol.