Total synthesis of the antifungal cyclic depsipeptides Sch 57697 and aureobasidin A

Article abstract of DOI:10.1016/0040-4039(96)01199-9

A novel cyclic depsinonapeptide antifungal 1a (Sch 57697) and its isomer 1b were synthesized by a fragment coupling approach and this methodology was applied to the total synthesis of the natural product aureobasidin A. Synthetic strategies for coupling of N-methyl amino acids with minimal racemization are discussed. Biological evaluation of isomers 1a and 1b demonstrated the importance of chirality at the β-hydroxy-N-methylvaline (OHMeVal) position.