| 摘要 |
PROBLEM TO BE SOLVED: To produce optically active pipecolic acid of a high optical purity useful as a synthetic intermediate for medicines, etc., in high yield by optically resolving an unmodified pipecolic acid. SOLUTION: (±)-Pipecolic acid is reacted with an optically active 2- phenoxypropionic acid in a medium comprising water, a lower alcohol or a mixture thereof in an optional proportion to afford S-(-)-pipecolic acid S-(-)-2- phenoxypropionate or R-(+)-pipecolic acid R(+)-2-phenoxypropionate produced as a sparingly soluble diastereomer salt. The resultant S-(-)-pipecolic acid S-(-)-2-phenoxypropionate or R-(+)-pipecolic acid R(+)-2-phenoxypropionate is then dissolved or suspended in water. An acid in an equivalent amount or an excess is further added to the resultant solution or suspension to carry out double decomposition. Thereby, an optically pure S-(-)-pipecolic acid (S-1) or R-(+)-pipecolic acid (R-1) is produced. |
