Total synthesis of (-)-bucidarasin a starting from an original chiral building block.

The highly stereoselective total synthesis of (-)-bucidarasin A, which also elucidated the absolute structure of its natural form, is described. The total synthesis features effective use of the original chiral building block prepared by us and a series of highly stereoselective reactions, i.e., hydroxy-directed hydrogenation, [4 + 2] cycloaddition of a sterically hindered dienophile, reduction of ketones, formation of the C9 side-chain diene, and formation of the THF moiety bearing two acetyloxy groups.