| abstract |
Novel compounds are provided having the formulaand salt thereof, where R<1 >is hydrogen, an alkyl, aralkyl, hydroxymethyl, carboxymethyl acyloxymethyl or trialkylsilyl group, or a group -CH2NR<3>R<4 >where N is a linking nitrogen atom and where (a) R<3 >and R<4 >are independently selected from hydrogen and alkyl, alkenyl, hydroxyalkyl and alkoxyalkyl groups; (b) R<3 >is hydrogen or an alkyl, alkenyl, hydroxyalkyl or alkoxyalkyl group, and R<4 >is -COR<5 >where R<5 >is hydrogen or an alkyl, alkenyl, hydroxyalkyl or alkoxyalkyl group; or (c) R<3 >and R<4 >taken together with the linking nitrogen atom form a saturated 3- to 7-member heterocyclic group. These compounds are useful intermediates in a process to prepare camptothecin derivatives including the anti-cancer drug irinotecan. |