Solid-Phase Total Synthesis of Sandramycin and Its Analogues.

Solid-phase total synthesis of sandramycin ( 1 ), which is a C 2 -symmetric cyclic decadepsipeptide natural product, and its analogues is described. On-resin ester formation and [5+5] peptide coupling allowed the preparation of a range of desymmetrized analogues. An amino acid residue that would not hamper the biological activity of 1 was successfully identified, and probe molecules and dimeric analogues were prepared on the basis of the result of the structure-activity relationship study.