A process for the preparation of N-monosubstituted β-aminoalcohol sulfonates of formula (Ia), (Ib): wherein R1 is C6-20-aryl or C4-12-heteroaryl, each optionally being substituted with one or more halogen atoms and/or one or more C1-4-alkyl or C1-4-alkoxy groups, R2 is C1-4-alkyl or C6-20-aryl, each aryl optionally being substituted with one or more halogen atoms and/or one or more C1-4-alkyl or C1-4-alkoxy groups and wherein R3 is selected from the group consisting of C1-18-alkyl, C6-20-cycloalkyl, C6-20-aryl and C7-20-aralkyl residues. The process has the steps of (a) reacting a methyl ketone, a primary amine, formaldehyde and a sulfonic acid, at a pressure above 1.5 bar, optionally in a organic solvent, the organic solvent optionally containing water, to afford N-monosubstituted β-aminoketone sulfonates of formula (II): wherein R1, R2 and R3 are as defined above, and (b) asymmetrically hydrogenating. The sulfonates in the presence of a base and a catalyst of a transition metal and a disphosphine ligand, in a polar solvent, optionally in the presence of water.