Formal Synthesis of Lobatamides A and C

Lobatamides, featuring a unique 15-membered dilactone core, are a family of marine natural products isolated from the tunicate <i>Aplidium lobatum</i> and exhibit inhibitory activity against mammalian vacuolar-type proton pump ATPase (V-ATPase). Herein, we report an alternative route to Sato’s intermediate, achieving formal syntheses of lobatamides A and C. Key steps include the palladium-catalyzed Suzuki–Miyaura coupling reaction to give a salicylic acid derivative containing a trisubstituted (<i>Z</i>)-olefin and the Nozaki–Hiyama–Takai–Kishi (NHTK) reaction to construct the 15-membered dilactone core.