Organocatalytic enantioselective formal synthesis of HRV 3C-protease inhibitor (1R,3S)-thysanone

A short and efficient organocatalytic enantioselective formal synthesis of HRV 3C-protease inhibitor (1R,3S)-thysanone is achieved in a nine-step with 98.7% enantiomeric excess, by employing l-proline-catalyzed asymmetric α-aminooxylation of aldehyde and Oxa-Pictet–Spengler cyclization as the key steps.