Concise synthesis of PM-94128 and Y-05460M-A.

The enantioselective total synthesis of PM-94128, a potent cytotoxin of microbial origin, was accomplished by a concise nine-step sequence of reactions in 14% overall yield from N-Boc-l-leucine. The synthesis of Y-05460M-A, a one-carbon lower homologue of PM-94128, was also achieved from N-Boc-l-valine by the same approach, which enabled its stereochemical determination.