Biomimetic total synthesis of plakortone Q via acid-mediated tandem cyclization.

Plakortone Q and plakdiepoxide are natural polyketides isolated from the marine sponge Plakortis simplex . Bicyclo[3.3.0]furanolactone compounds, including plakortone Q, are expected to exhibit a wide range of pharmacological activities. Therefore, developing a simple and versatile synthetic method to produce these compounds is an important research goal. We have achieved the first total synthesis of plakortone Q and plakdiepoxide through an efficient protecting-group-free strategy. The key transformation was an acid-mediated tandem 5- endo-tet /5- endo-tet cyclization of vicinal diepoxide to build the tetrahydrofuran-γ-lactone motif.