A new facile synthesis of (2S,5S)-5-hydroxypipecolic acid hydrochloride

A simple and efficient synthesis of (2S,5S)-5-Hydroxypipecolic acid hydrochloride is reported. The key features of the synthesis involve the asymmetric reduction of ketone using (S)-CBS oxazaborolidine and the use of commercially available methyl pyroglutamate as a starting material.