S-(4'-methylphenyl) (2R,3S)-2-benzylamino-3-tert-butyldimethylsilyloxy-4-methylpentanethioate

S-(4'-methylphenyl) (2S,3S)-2-tert-butoxycarbonylamino-3-tert-butyldimethylsilyloxy-4-methylpentanethioate