Application and Scope of Schreiber's Gold(I)‐Catalyzed α‐Pyrone Synthesis to Ring A Aromatic Podolactones

Abstract

Abstract Schreiber's gold(I)‐catalyzed synthesis of α‐pyrones was adapted to the total synthesis of a ring A aromatic podolactone, urbalactone. The scope of the acetylenic ester partner in the formation of α‐pyrones was studied. The total synthesis features, as key steps, α‐pyrone formation, Friedel–Crafts cyclization, Stille coupling, and a N , N′ ‐dicyclohexylcarbodiimide/4‐( N , N ‐dimethylamino)pyridine lactonization to generate the γ‐lactone. Several α‐pyrone intermediates from this work exhibited in vitro antiproliferative activity against the A2780 ovarian cancer cell line.