5-[1,2]-dithiolan-3-yl-pentoic acid 2-{2-[2-(2-hydroxy-ethoxy)-ethoxy]-ethoxy}-ethyl ester 、
camptothecin C20-chloroformate 以
二氯甲烷 为溶剂,
反应 16.0h,
以136 mg的产率得到2-[2-[2-[2-[[(19S)-19-ethyl-14,18-dioxo-17-oxa-3,13-diazapentacyclo[11.8.0.02,11.04,9.015,20]henicosa-1(21),2,4,6,8,10,15(20)-heptaen-19-yl]oxycarbonyloxy]ethoxy]ethoxy]ethoxy]ethyl 5-(dithiolan-3-yl)pentanoate