西他沙星关键中间体胺基氮杂螺环的不对称合成

Asymmetric synthesis of an amine-azaspiro as the key intermediate of sitafloxacin

摘要: 7-(S)-(叔丁氧羰基胺基)-5-氮杂螺［2.4］庚烷是合成新一代喹诺酮类抗生素西他沙星和欧拉沙星的关键中间体，但现有合成方法收率低、立体选择性较差。本研究对其合成工艺进行了改进，开发了一种新的不对称合成方法，反应的收率和立体选择性得到了明显提高，且原料易得，步骤短，所得手性异构体光学纯度高。

Abstract: As an important intermediate of quinolone antibacterial agents such as sitafloxacin and olamufloxacin, 7-(S)-tert-butoxycarbonylamino-5-azaspiro［2. 4］heptane has received much attention. Previous syntheses suffered from low yielding and poor stereoselectivity. In this study, an asymmetric synthetic approach was developed to optically pure amine-azaspiro compound with convenient manipulation, excellent yields and high stereoselectivity.