Catalytic Asymmetric Total Synthesis of Naturally Occurring Amaryllidaceae Alkaloid, (+)-11-Hydroxyvittatine

The first catalytic asymmetric total synthesis of naturally occurring (+)-11-hydroxyvittatine (1a) has been achieved in 9 steps and an overall yield of 14.4%. The enantioselectivity was achieved using an organocatalytic Corey-Itsuno reduction. Subsequent Mitsunobu reaction and a microwave-assisted intramolecular carbonyl-ene reaction enabled the construction of the core structure with three fixed stereocenters. Finally, a Pictet-Spengler cyclization completes the total synthesis of (+)-11-hydroxyvittatine (1a). Our synthesis relies on simple and classical reactions to address the Amaryllidaceae alkaloids and will serve as an efficient route to access the other congeners.