Total synthesis of (+/-)-lysergic acid, lysergol, and isolysergol by palladium-catalyzed domino cyclization of amino allenes bearing a bromoindolyl group.

Ergot alkaloids and their synthetic analogs have been reported to exhibit broad biological activity. We investigated direct construction of the C/D ring system of ergot alkaloids based on palladium-catalyzed domino cyclization of amino allenes. With this biscyclization as the key step, total synthesis of (+/-)-lysergic acid, (+/-)-lysergol, and (+/-)-isolysergol was achieved.