4-Substituted-2-hydroxybutanoates and a process for producing them

摘要

The present invention provides an optically active 4-substituted-2-hydroxybutanoate represented by the general formula: <IMAGE> (I) wherein X is Cl, Br, I or Cn, R is alkyl, and * shows an asymmetric carbon. The compounds which are useful as starting materials for medical agents, are obtained by a process comprising ring-opening optically active alpha -hydroxy- gamma -butyrolactone and esterifying the compound obtained.