Chiral hydroxyethylamine, hydroxyethylurea or hydroxyethylsulfonamide isostere containing retroviral protease and renin inhibitors can be prepared by multi-step syntheses that utilize key chiral amine intermediates. This invention is a cost effective method of obtaining such key chiral amine intermediates enantiomerically, diastereomerically and chemically pure. The method is suitable for large scale (multikilogram) productions. This invention also encompasses organic acid and inorganic acid salts of the amine intermediates.