| abstract |
Various intermediates as defined in the specification for preparing camptothecin derivatives, other compounds related to the synthesis of CPT-11 of formula (I) and compounds related to mappicine of formula (II) are claimed. The intermediates are based on 4-keto-pyridine, 2-pyridine-1,3-dioxolane, pyrano[3,4-c]pyridine, pyrano[3,4-c]indolizine or indolizine or on a compound of formula II. Also claimed are the processes for preparing the above compounds. |