An efficient synthesis of (S)-and (R)-3-hydroxypiperidin-2-ones from methyl 5-nitro-2- oxopentanoate is described. A one-pot enzyme catalysed hydrolysis of the ester and reduction of the ketone gave enantiopure 2-hydroxy-5-nitropentanoic acids which on esterification, catalytic hydrogenation over a platinum (IV) oxide catalyst and intramolecular cyclisation gave the target compounds in 93% overall yield and> 99% ee.
