A Highly Stereoselective Total Synthesis of (+)‐9‐<i>epi</i>‐Dictyostatin

Abstract

Abstract The total synthesis of (+)‐9‐ epi ‐dictyostatin ( 1b ), a diastereomer of the antimitotic marine‐sponge‐derived macrolide (–)‐dictyostatin ( 1a ), was achieved by creating 11 stereogenic centers and 4 stereogenic double bonds with a high level of stereocontrol. The yield for the 29‐step longest linear sequence from Roche ester was 1.53 %. The final key steps to this unnatural product were the vinylzincate C10–C26 addition to aldehyde C1–C9 (leading surprisingly to a complete stereoselectivity for the 9 R ‐epimer), followed by Yamaguchi macrolactonization and global deprotection.