A stereodivergent strategy for the synthesis of skippeddienes is developed. The method consists of hydroboration of allenes and Migita-Kosugi-Stille coupling, which allows for access to all four possible stereoisomers of the skippeddienes. The hydroboration is especially useful for providing both E-allylic and Z-allylic alcohols from the same allene by simply changing the organoborane reagent. The
The full details of a unified totalsynthesis of madangamine alkaloids are disclosed. Our central strategy is based on the construction of a common ABCE-tetracyclic system, followed by the late-sta...