Process for the preparation of
acetal-protected sugars comprising the step of reacting a
diol group of a
sugar selected from the group consisting of valeralose and
hexaldehyde with one or both compounds of formula (Ia) and / or formula (Ib) in the presence of a homogeneous or heterogeneous catalyst, to form an
acetal protected
sugar selected from the group consisting of compounds of formula (II), formula (III) and formula (IV); wherein R1 and / or R2 are each independently-Z-X, and wherein Z is a linear, branched or
cyclic hydrocarbon moiety having 1 to 10 carbon atoms, optionally substituted by 1 to 4 C1-C4
alkyl groups or 1 to 4
halogen atoms, or Z is-B-D, where B is a linear
hydrocarbon moiety having 1 to 3 carbon atoms and may be present or absent, D is an
aromatic moiety having 6 carbon atoms, wherein Z may be present or absent, and X is-COOH,-CH (COOH) 2,-COOR3, CHO,-C2H3,-C2H,-CHOR4OR5,-N3,-NHR6,-NR7R8,-F,-Cl,-Br,-I, or, if Z is present, X is-OH, NH2, or-SH, optionally substituted by 1 to 4 C1-C4
alkyl groups, 1 to 2-OH groups, 1 to 2-OCH3 groups, or 1 to 4
halogen atoms, and wherein Z may be present or absent,-COOR3, CHO,-C2H3,-C2H,-CHOR4OR5,-N3,-NHR6,-NR7R8,-F,-Cl,-Br,-I; r3, R4 and R5 are independently selected from the group consisting of linear, branched or
cyclic hydrocarbon moieties having 1 to 20 carbon atoms and optionally substituted by 1 to 4 C1 to C4
alkyl groups and / or 1 to 4
halogen atoms selected from the group consisting of
fluorine,
chlorine,
bromine and
iodine; r6 is a C1-C4 alkyl group; r7, R8 and R9 are each independently a C1-C4 alkyl group; r30 and R31 are each independently selected from the group consisting of
hydrogen and a linear or branched
hydrocarbon moiety having 1 to 4 carbon atoms, with the proviso that R30 and R31 cannot be
hydrogen at the same time; r < 10 > is selected from the group consisting of-H,-OH,-CH2OH,-OR13 or-CH2OR14; r < 11 > and R < 12 > are independently selected from the group consisting of-OH or-OR13; r13 and R14 are independently selected from
hydrocarbon moieties having from 1 to 10 carbon atoms; and n and p are each independently 0 or 1.