Droxidopa (hydrochloride) synthesis

Yield:-

Steps:

Multi-step reaction with 4 steps
1.1: lithium diisopropyl amide / tetrahydrofuran / 0.5 h / -78 °C / Inert atmosphere
1.2: 8 h / 20 °C / Inert atmosphere
2.1: ((R,R)-Ts-DENEB)RuCl; formic acid; diethylamine / dichloromethane / 40 h / 0 - 40 °C
3.1: lithium hydroxide / tetrahydrofuran; ethanol / 8 h / 20 °C
4.1: palladium on activated charcoal; hydrogen; hydrogenchloride / ethanol / 6 h / 20 °C / 760.05 Torr

References:

Sun, Guodong;Zhou, Zihong;Luo, Zhonghua;Wang, Hailong;Chen, Lei;Xu, Yongbo;Li, Shun;Jian, Weilin;Zeng, Jiebin;Hu, Benquan;Han, Xiaodong;Lin, Yicao;Wang, Zhongqing [Organic Letters,2017,vol. 19,# 16,p. 4339 - 4342]