Enantioselective Total Synthesis of Rhodocoranes C, D, and E by Chiral Lithium Amide Alkylation and Gold-Catalyzed Spirocyclization

Abstract

We report the first enantioselective total syntheses of rhodocoranes C, D, and E, acorane sesquiterpenoids isolated from the endangered basidiomycete Rhodotus palmatus. Key steps include a chiral lithium amide-mediated alkylation to establish a requisite stereogenic center and a gold-catalyzed dearomative spirocyclization to construct the spiro[4.5]decane acorane core. Divergent late-stage functionalization from a common ene-1,4-diketone intermediate completed the syntheses of all three natural products from achiral starting materials.