I. Moldvai et al., Chemistry of indoles carrying a basic function. Part IV - Synthesis of D-norergoline and ergoline ring by Stobbe reaction, HETEROCYCLE, 51(10), 1999, pp. 2321-2333
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.