Synthesis of (±)-annonelliptine and (±)-anomoline

In order to confirm the structures of annonelliptine [1] and anomoline [2]. chemical synthesis of (±)-1 and (±)-2 has been achieved. Two isomeric alkaloids, (±)-N-northalmeline [3] and (±)-thalmeline [4] were also prepared by a similar approach. The structures of 1 and 2 were confirmed unequivocally by comparison with the synthetic samples. COLOC and nOe nmr spectra were also used to study the structures of these compounds. © 1995, American Chemical Society. All rights reserved.