Stereoselective synthesis of chiral β-amino trifluoromethyl alcohol: development of a manufacturing process for a key intermediate in the production of a novel elastase inhibitor, AE-3763

We have successfully synthesized chiral β-amino trifluoromethyl alcohol (2S,3S)-7a, which is a key intermediate in the production of AE-3763, by stereoselective reduction of N-Cbz-protected 5-hydroxy-5-(trifluoromethyl)-1,3-oxazolidine 4 prepared from L-valine in 3 steps followed by alkaline hydrolysis. This new method can be applied to the industrial-scale synthesis of AE-3763.