Structure assignment of lagunapyrone B by fluorous mixture synthesis of four candidate stereoisomers

Techniques of fluorous mixture synthesis are used to make four candidate stereoisomers for the natural product lagunapyrone B. Stille coupling of the resulting pure quasienantiomers with the quasiracemic mixture has provided two quasi-diastereomeric samples that are demixed and detagged to provide all four lagunapyrone B stereoisomers, which are assigned the 6R,7S,19S,20S,21R configuration by comparison of optical rotations.