- Improved process for pilot-scale synthesis of danshensu ((±)-DSS) and its enantiomer derivatives
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A pilot-scale process has been developed for green and scalable synthesis of (±)-β-(3,4-dihydroxyphenyl) lactic acid ((±)-DSS) and their two important derivatives, namely, (±)-IDHP [(±)-isopropyl 2-hydroxy-3-(3,4-dihydroxyphenyl)propanoate] and (±)-DBZ [(±)-bornyl 2-hydroxy-3-(3,4-dihydroxyphenyl)propanoate]. Subsequent hydrogenation has been carried out by employing Raney Ni as catalyst. The improved process results in higher yields of 47.5% for (±)-DBZ and 49.2% for (±)-IDHP compared to the initial process with a yield of 12% for (±)-DBZ and 18% for (±)-IDHP in our original medicinal chemistry route. Furthermore, kilograms of optical DBZ [(-)-S-DBZ and (+)-R-DBZ, >99% ee] and IDHP [(-)-S-IDHP and (+)-R-IDHP, >99% ee] have been produced by chiral high-performance liquid chromatography in good yield (>84%).
- Bai, Yajun,Zhang, Qunzheng,Jia, Pu,Yang, Lingjian,Sun, Yuhong,Nan, Yefei,Wang, Shixiang,Meng, Xue,Wu, Yizhen,Qin, Fanggang,Sun, Zhe,Gao, Xiaokang,Liu, Pei,Luo, Kai,Zhang, Yajun,Zhao, Xinfeng,Xiao, Chaoni,Liao, Sha,Liu, Jianli,Wang, Cuiling,Fang, Jiacheng,Wang, Xiaoxiao,Wang, Jing,Gao, Rong,An, Xuexia,Zhang, Xunli,Zheng, Xiaohui
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p. 1667 - 1673
(2015/02/18)
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- Efficient and practical asymmetric synthesis of isopropyl (R)-3-(3′,4′-dihydroxyphenyl)-2-hydroxypropanoate and its enantiomer
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The highly enantioselective synthesis of (R)-isopropyl 3-(3′, 4′-dihydroxyphenyl)-2-hydroxypropanoate and its enantiomer has been achieved starting from 3,4-dihydroxybenzaldehyde. The stereogenic centers were established through asymmetric dihydroxylation of (E)-isopropyl 3,4-bis(benzyloxy) cinnamate. A convenient manipulation in selective catalytic hydrogenation and deprotection was also accomplished in HCl-iPrOH employing 10% Pd/C catalyst.
- Chen, Ming,Chen, Hui,Wang, Yuzhen,Wang, Haibo,Nan, Yefei,Zheng, Xiaohui,Jiang, Ru
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