AbstractIn order to prepare selectively α‐aminoalcohol R*S* diastereoisomers by adding Grignard reagents to the corresponding α‐aminoketones, the influence of the following factors has been studied successively: permutation of substituents: reagents–substrates, complexing nature of the solvent, addition of magnesium salts, and nature of the halogen. In this way a list has been drawn up of experimental conditions leading to selective or specific preparation of aminoa