Formal Synthesis of Premisakinolide A and C(19)-C(32) of Swinholide A via Site-Selective C-H Allylation and Crotylation of Unprotected Diols

Using stereo- and site-selective C-H allylation and crotylation of unprotected diols, an intermediate in the synthesis of premisakinolide A (bistheonellic acid B) that was previously made in 16-27 (LLS) steps is now prepared in only nine steps. This fragment also represents a synthesis of C(19)-C(32) of the actin-binding macrodiolide swinholide A.