Synthesis of new didemnin B analogs for investigations of structure/biological activity relationships

Synthesis of didemnin B analogs that contain the modified L-lactyl-L-propyl portion of the side chain helps analyze structure-activity relationships in this region and the factors responsible for bioactivities of this natural product. Use of a Dess-Martin periodinane reagent and a coupling reagent helps produce gram quantities of the didemnin B macrocycle. Threonine, N-methyl-D-leucine and proline influence the bioactivity of this compound.