The limited availability of bioactive natural products for pharmaceutical studies and drug development is a problem that can be solved, in principle, by total synthesis. The potent antitumor marine natural products ecteinascidin 597 (I; R = Me) and ecteinascidin 583 (I; R = H) have now been synthesized from readily accessible starting materials in a highly convergent and stereoselective fashion (see scheme). [on SciFinder (R)]