Asymmetric Synthesis of Ramariolides A and C through Bimetallic Cascade Cyclization and Z-E Isomerization Reaction.

A short and flexible asymmetric synthesis of ramariolides A and C was accomplished. A bimetallic catalytic system consisting of Pd-Cu-mediated cascade cyclization, unprecedented Z-E isomerization by a Ru-based metathesis catalyst, and late-stage stereoselective epoxidation are the key steps involved in the synthesis.