METHOD FOR PRODUCING OPTICALLY ACTIVE CARBOXYLIC ACID HAVING SUBSTITUENT AT 2-POSITION

摘要

PROBLEM TO BE SOLVED: To provide a method for efficiently producing an optically active 2-chlorocarboxylic acid and 2-acetylthiocarboxylic acid with high optical purity from easily available raw materials. SOLUTION: An optically active 2-hydroxycarboxylic acid (1) capable of being derived from an optically active 2-aminocarboxylic acid (4) is acted by both of thionyl chloride and a base component to be chlorinated while involving the inversion of configuration at 2-position and to be led to an optically active 2-chlorocarboxylic acid chloride (5), followed by hydrolyzing the 2- chlorocarboxylic acid chloride to lead it to an optically active 2-chlorocarboxylic acid (2). Further, the 2-chlorocarboxylic acid is reacted with a thioacetate to be converted into the acetylthio compound of the 2-chlorocarboxylic acid while involving the inversion of configuration at 2-position in such a way that an optically active 2-acetylthiocarboxylic acid (3).