Total Synthesis of Tubulysin U and V

Multicomponent method: Tubulysins are among the most potent cytotoxic agents known. Now the first total synthesis of some members has been achieved by utilizing a rapid three-component reaction for the synthesis of the unusual central thiazole amino acid tubuvaline (see scheme; Boc=tert-butoxycarbonyl, Ac=acetyl), thereby opening new perspectives for anticancer drug development.