A readily available and inexpensive natural -amino acid is converted into a compound represented by formula (1), which is then reacted with an organometallic reagent represented by formula (2) to give an optically active 5-hydroxyoxazolidine represented by formula (3), which is then treated with an acid to provide an optically active aminoketone represented by formula (4). The product is then converted into an optically active aminoalcohol represented by formula (5) or (6) by, for example reduction. ##STR1##