Preparation of Ethyl (R)-3-hydroxy-4-chlorobutyrate by Selective Reduction of (R)-4-(Trichloromethyl)-oxetan-2-one: Key Intermediate to (R)-Carnitine and (R)-4-Amino-3-hydroxybutyric Acid

Abstract Selective reduction of (R)-4-(trichloromethyl)-oxetan-2-one in ethanol by catalytic hydrogenation on Pd-C in the presence of KOAc gave directly ethyl (R)-3-hydroxy-4-chlorobutyrate, which can be used as a key intermediate for the synthesis of some biologically active γ-amino-β-hydroxy amino acids, (R)-carnitine and γ-amino-β-hydroxy amino acid (R)-GABOB).