<p>An original palladium-catalyzed ring opening carbonylative lactonization of synthetic available hydroxycyclopropanols was reported to efficiently synthesize tetrahydrofuran (THF) and tetrahydropyran (THP)-fused bicyclic γ-lactones, two unique scaffolds often found in quite a few natural products. This new developed reaction features mild reaction conditions, good functional group tolerability, and the scale-up abilities. The synthetic application was demonstrated in a short total synthesis of (±)-Paeonilide. The THF-fused bicyclic γ-lactone products can be readily diversified into some medicinally important structures, which further broadens the application of this new carbonylation approach.</p> <p>The first total synthesis of Phleghenrine A was reported. This synthesis features an unprecedented inverse electron-demand Diels-Alder reaction and Tiffeneau-Demjanov ring expansion to rapidly construct bicyclo[3,2,2]-nonane core structure of Phleghenrine alkaloids. Two Diels-Alder adducts were synthesized, which were the synthetic precursors for divergent synthesis of Phleghenrine A and B, respectively.</p>

<p>Total synthesis of massarinolin A, purpurlides B, D, E, 2,3-deoxypurpurolide C, phleghenrines A and B were finished. A halogen bond promoted michael addiation was discovered during mechanism study toward diamination of allenes. Computational chemsitry study conducted toward the selectivity of 2+2 reaction supported the proposed key reaction during total synthesis of gibberellic acid 18.</p>