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.
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 for the total asymmetric synthesis of 20(S)-camptothecin anticancer drugs, is described. Its structure was characterized by 2D-NMR techniques and the absolute configuration was further confirmed for the first time by X-ray crystal structure analysis.
Kuang
Yun-Yan
YY
Department of Chemistry, Fudan University, Shanghai 200433, People's Republic of China. yykuang@fudan.edu.cn
Chen
Fen-Er
FE
D000085:Acetates / Q000138:chemical synthesis / Q000737:chemistry; D002166:Camptothecin / Q000138:chemical synthesis / Q000737:chemistry; D018360:Crystallography, X-Ray; D008968:Molecular Conformation; D015394:Molecular Structure; D013329:Structure-Activity Relationship
D000085:Acetates; D002166:Camptothecin