Enantiodivergent Total Syntheses of (+)- and (−)-Scopadulcic Acid A

The first enantioselective total synthesis of scopadulcic acid A is described. The key step is a cascade intramolecular Heck reaction of a methylenecycloheptene iodide, which generates the B, C, and D rings of the scopadulan ring system in 90% yield as a single stereoisomer. A distinctive feature of these syntheses is the use of stereoselective enolization to dictate which enantiomer of the natural product is produced.