Process for producing camptothecin

摘要

Problem: A large scale production of camptothecin, which is a starting compound of irinotecan hydrochloride and various camptothecin derivatives, at a low cost and with ease.Solution: A process for preparing camptothecin, characterized in that it comprises the following steps (a) and (b);(a) the step to hydrolyze 9-methoxycamptothecin or a natural material containing 9-methoxycamptothecin;(b) the step to convert 9-hydroxycamptothecin obtained in the step (a) into camptothecin by 9-O-perfluoro-lower-alkylsulfonylation or 9-O-phenyltetrazolylation, followed by hydrogenolysis.