Total Synthesis of the Marine Natural Product (−)-Clavosolide A. A Showcase for the Petasis−Ferrier Union/Rearrangement Tactic

The total synthesis of the marine diolide (−)-clavosolide A has been achieved in 17 steps (longest linear sequence) from commercially available
crotonaldehyde exploiting the Petasis−Ferrier union/rearrangement tactic to construct the requisite aglycon monomer. A one-pot esterification/lactonization employing the Yamaguchi protocol, followed by bis-glycosidation, furnished (−)-clavosolide A.