Plant antitumor agents. 28. Resolution of a key tricyclic synthon, 5'(RS)-1,5-dioxo-5'-hydroxy-2'H,5'H,6'H-6'-oxopyrano[3',4'-f].DELTA.6,8-tetrahydroindolizine: total synthesis and antitumor activity of 20(S)- and 20(R)-camptothecin
作者:Mansukh C. Wani、Allan W. Nicholas、Monroe E. Wall
DOI:10.1021/jm00395a024
日期:1987.12
The resolution of the tricyclic ketone (3a + 3b) by the separation of diastereomeric adducts 4a and 4c of the precursor ketal 5 is described. The regenerated enantiomers 3a and 3b of 100% optical purity represent the key intermediates from which 20(R)-camptothecin (1a) and 20(S)-camptothecin (1b), respectively, have been prepared. The 20R analogue 1a was 10-100 times less active than the natural 20(S)-camptothecin
描述了通过分离前体缩酮5的非对映加合物4a和4c来分离三环酮(3a + 3b)的方法。光学纯度为100%的再生对映异构体3a和3b代表了分别制备20(R)-喜树碱(1a)和20(S)-喜树碱(1b)的关键中间体。在9KB和9PS细胞毒性试验中,20R类似物1a的活性比天然20(S)-喜树碱(1b)低10-100倍,在体内L-1210白血病试验中几乎无效,与高效天然活性化合物相比1b。