A Novel and Enantioselective Total Synthesis of (20S)-Camptothecin via a Sharpless Asymmetric Dihydroxylation Strategy

A novel and efficient asymmetric total synthesis of (20S)-camptothecin has been accomplished in an overall yield of 12% starting from the commercially available 2-methoxynicotinic acid. The key step in the sequence is the Sharpless asymmetric dihydroxylation of a 4-(but-1-en-2-yl)pyridine derivative to establish the stereocenter of (20S)-camptothecin.