PROCESSES FOR THE PRODUCTION OF OPTICALLY ACTIVE COMPOUNDS HAVING SUBSTITUENTS AT THE 2-POSITION

摘要

Optically active compounds having thio groups at the 2-position which are important to the production of drugs and so on can be produced with minimized racemization in high yield and at a low cost by chlorinating an optically active compound having a hydroxyl group at the 2-position with the inversion of configuration at the 2-position to form an optically active compound having a chlorine atom at the 2-position, and reacting the optically active compound having a chlorine atom at the 2-position with a metal thiolate to introduce a thio group to the compound with the invention of configuration at the 2-position. Further, optically active compounds having thio groups at the 2-position can be produced at higher optical purities and in higher yields by conducting the reaction of an optically active compound having a chlorine atom at the 2-position with a metal thiolate in the presence of water. Additionally, optically active carboxylic acids having thio groups at the 2-position can be efficiently rid of coexistent impurities such as optical isomers by crystallization in the presence of an aliphatic hydrocarbon solvent and/or a sulfur-containing solvent, whereby optically active carboxylic acids having thio groups at the 2-position can be obtained as crystalline substances at further enhanced purities.