Divergent Asymmetric Total Synthesis of Mulinane Diterpenoids

A concise, divergent, asymmetric total syntheses of mulinane diterpenoids has been achieved. Specifically, a new strategy was developed featuring a key intramolecular Friedel–Crafts reaction to construct the chiral fused 5‐6‐6 tricyclic motif, followed by sequential Birch reduction, conjugate methylation, and homologation/ring‐expansion reactions to furnish the desired 5‐6‐7 tricyclic skeleton bearing five contiguous stereocenters. With this efficient strategy, seven mulinane diterpenoids and two analogues were synthesized via late‐stage functional modification or functionalization in 8.6–20 % overall yields and 11–15 steps. The asymmetric total synthesis of mulinane diterpenoids was developed in a concise and divergent fashion, providing seven mulinane diterpenoids and two analogues in 8.6–20 % overall yield and 11–15 steps.