用一种可回收的配体催化合成紫杉醇C_(13)片段

Synthesis of taxol side chain precursor with a new recoverable ligand

目的 :建立一种经济的方法合成紫杉醇C1 3 侧链(2R ,3S) 3 苯甲酰胺基 2 羟基 3 苯基丙酸异丙酯 2 .方法 :以反式肉桂酸异丙酯为原料 ,N 溴代苯甲酰胺为助氧化供氮试剂 ,在配体 4存在下进行锇催化的不对称氨羟化反应 ,可以得到很高光学产率的抗癌药物紫杉醇的C1 3 片段 2 .当反应结束后 ,向体系加入少量乙醚 ,过滤 ,就可使配体 4得到回收 .结果 :C1 3 片段 2化学产率 39% ,对映体过量 98% .配体回收率76 % .结论 :这种合成方法成本低 ,操作简便 .特别是配体容易合成 。

AIM: To develop a simple and economical method to achieve taxol side chain precursor, (2R,3S) isoproplyl 3 benzamido 2 hydroxy 3 phenylpropionate. METHODS: A highly enantioselective C 13 side chain 2 was obtained by osmium catalyzed asymmetric aminohydroxylation (AA) of isopropyl trans cinnamate, with N bromobenzamide as an oxidant /nitrogen reagent in the presence of ligand 4. After reaction, diethyl ether was added and filtered and ligand was recovered. RESULTS: Total yield of C 13 side chain 2 was 39%, the enantiomeric excess was 98% and recovery rate of ligand 4 was 76%. CONCLUSION: This synthetic process is simple and economical, for the ligand, better than polymer surpported ligand, can be easily prepared, recovered and reused.