A Divergent Approach to the Marine Diterpenoids (+)-Dictyoxetane and (+)-Dolabellane V.

We present a full account of the development of a strategy that culminated in the first total syntheses of the unique oxetane-containing natural product (+)-dictyoxetane and the macrocyclic diterpene (+)-dolabellane V. Our retrosynthetic planning was guided by both classical and nonconventional strategies to construct the oxetane, which is embedded in an unprecedented 2,7-dioxatricyclo[4.2.1.0