(-)-tert-butyl [(1R)-1-formyl-3-phenylpropyl]carbamate

(3R)-N-tert-Butoxycarbonyl-5-phenyl-3-amino-2-hydroxypentanonitrile

{(R)-4-[(R)-1-(Benzooxazol-2-yl-hydroxy-methyl)-3-phenyl-propylcarbamoyl]-4-tert-butoxycarbonylamino-butyl}-carbamic acid tert-butyl ester

((R)-4-tert-Butoxycarbonylamino-4-{(R)-1-[(5,6-dimethyl-benzooxazol-2-yl)-hydroxy-methyl]-3-phenyl-propylcarbamoyl}-butyl)-carbamic acid tert-butyl ester