N-isopropylsulfinylimines as useful intermediates in the synthesis of chiral amines: expeditive asymmetric synthesis of the calcimimetic (+)-NPS R-568.

An efficient and high-yielding approach for the asymmetric synthesis of calcimimetic (+)-NPS R-568 (1) has been developed. The key step of the synthesis is the highly diastereoselective addition of methyl Grignard to the (SS,E)-N-(3-methoxybenzylidene)-2-propanesulfinamide [5(S)], which afforded a single diastereoisomer in high yield in short reaction time.