Divergent Synthesis of 17‐nor‐Cephalotane Diterpenoids through Developed Ynol‐diene Cyclization

On the basis of a novel ynol‐diene cyclization developed as a rapid access to tropone unit, the first divergent strategy to 17‐ nor ‐cephalotane diterpenoids has been successfully established. Combining with a bioinspired stereoselective dual hydrogenation, the divergent total synthesis of (+)‐3‐deoxyfortalpinoid F, (+)‐harringtonolide, (−)‐fortalpinoids M/N/P, and analog (−)‐20‐deoxocephinoid P have been achieved in 14–17 linear longest steps starting from commercially available materials.