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

作者：Hugelshofer Cedric L; Magauer Thomas^*

来源：Chemistry - A European Journal, 2016, 22(42): 15125-15136.

DOI：10.1002/chem.201603061

• oxetane
• natural products
• rearrangements
• terpenoids
• total synthesis

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(3,8)] nonane ring system. Highlights of the successful approach include highly diastereoselective carbonyl addition reactions to assemble the full carbon skeleton, a Grob fragmentation to construct the 11-membered macrocycle of (+)-dolabellane V, and a bioinspired 4-exo-tet, 5-exo-trig cyclization sequence to form the complex dioxatricyclic framework of (+)-dictyoxetane. Furthermore, an unprecedented strain-releasing type I dyotropic rearrangement of an epoxide-oxetane substrate was developed.

• 出版日期2016-10