Chemistry of indoles carrying a basic function. Part IV - Synthesis of D-norergoline and ergoline ring by Stobbe reaction

Starting from Uhle's ketone (2), pentacyclic lactone derivatives with D-nor ergoline ring (13 and 14) have been prepared by an unusual intramolecular S tobbe reaction of a succinic diester derivative (3a). The preparation of er goline ring (1) itself was also achieved through modification of the reacti on conditions.