(20S)-7-t-Butyldimethylsilyl-10-hydroxycamptothecin 1H-Pyrano[3',4':6,7]indolizino[1,2-b]quinoline-3,14(4H,12H)dione, 11-[(1,1-dimethylethyl)dimethylsilyl]-4-ethyl-4,9-dihydroxy-, (4S)- 220913-32-6 NSC708298