Asymmetric Total Synthesis and Revision of Absolute Stereochemistry for (+)-Taumycin A: An Approach that Exploits Orthogonally Protected Quasienantiomers.

The first asymmetric total synthesis of C(9)-S-(+)-taumycin A is now reported using an approach that targeted both C(9) diastereomers concurrently. To facilitate this work, we called upon the symmetrical nature of a C(5)-C(13) side-chain intermediate and exploited orthogonal protecting groups as a tactic to access both stereoisomers from a single chiral, nonracemic intermediate. In addition to our successful approach, several minor detours that helped refine our strategy and a detailed analysis of 1H NMR data will be discussed. Select compounds included in this work were screened against the NCI60 cell line panel and displayed modest growth inhibition activity.