Total Synthesis of Biselide E, a Marine Polyketide.

The total synthesis of biselide E, a marine polyketide isolated from the Okinawan ascidian, has been accomplished. The highlight of this approach is the use of the ß-elimination reaction of the chloroacetoxy group for the construction of an unstable six-membered α,ß,γ,δ-unsaturated lactone portion at the late stage of the total synthesis.