| 摘要 |
<p>Preparation of optically active piperazine carboxylic acid derivatives of formula (I) comprises asymmetrically hydrogenating a corresponding pyrazinecarboxylic acid derivative of formula (II) in the presence of an optically active rhodium complex catalyst. X = OH, 1-6C alkoxy or NR<1>R<2>; R<1>, R<2> = H, 1-6C alkyl, 3-6C cycloalkyl, aryl or amino protecting group; or NR<1>R<2> = optionally substituted 5- or 6-membered saturated heterocycle.</p> |
