Process for cyclizing optically active 4-amino-2-halogenobutyric acids

Abstract

The invention provides a process for producing optically active azetidine-2-carboxylic acid with good efficiency, expedience, and commercial advantage, which comprises cyclizing an optically active 4-amino-2-halogenobutyric acid in an optical yield of as high as 90% or more. It is a process for producing optically active azetidine-2-carboxylic acid of the general formula (2), in which * denotes an asymmetric carbon atom, which comprises cyclizing an optically active 4-amino-2-halogenobutyric acid of the general formula (1), in which X represents a halogen atom and * denotes an asymmetric carbon atom, in the presence of an oxide of an alkaline earth metal, a hydroxide of an alkaline earth metal excepting barium, or an organic amine.

Dependencies are inferred from the claim text.