We report an asymmetric synthesis of chiral amines (4S,5S)-Cytoxazone, Taxol side chain moiety and (S )- Levetiracetam starting from versatile new chiral N- sulfinimine ( 4 ). The key step, stereoselective 1,2-addition of Grignard reagent to chiral N-sulfinimine derived fr om (R)-glyceraldehyde acetonide and (S)-t-BSA gave the corresponding sulfonamide in high diastereoselecti vity. Subsequent reactions yielded the targeted biologica l active and pharmaceutical important compounds with high pu rity (>99%) and yield