Efficient synthesis of dolastatin 15 (1) was accomplished following a convergent strategy. The pyrrolidinone cycle of 5 was obtained by thermic cyclization of the corresponding Meldrum's adduct 4. The methylation of the enol function was performed under Mitsunobu conditions. On the other hand, the peptidepart 10 was elongated by using PyCloP as coupling reagent. The ester linkage between both segments