Synthesis and Molecular Structure of Ethyl [N-tosyl-(R)-prolyloxy]-2(S)-[4-cyano-8,8-ethylenedioxy-5-oxo-5,6,7,8-tetrahydroindolizin-3-yl] Acetate, a Key Intermediate in the Total Synthesis of (20S)-Camptothecins
oleh: Fen-Er Chen, Yun-Yan Kuang
| Format: | Article |
|---|---|
| Diterbitkan: | MDPI AG 2007-11-01 |
Deskripsi
The synthesis of optically active [N-tosyl-(R)-prolyloxy]-2(S)-[4-cyano-8,8-ethylenedioxy-5-oxo-5,6,7,8-tetrahydroindolizin-3-yl] acetate (4a), a key intermediate forthe total asymmetric synthesis of 20(S)-camptothecin anticancer drugs, is described. Itsstructure was characterized by 2D-NMR techniques and the absolute configuration wasfurther confirmed for the first time by X-ray crystal structure analysis.