ORMOSIA ALKALOIDS: III. CHEMISTRY OF ORMOSANINE AND ORMOJANINE; DEHYDROGENATION TO 3,6,8-TRIALKYLATED QUINOLINES

Degradations of ormosanine, C20H35N3, are described which are in agreement with structure II (8) for this alkaloid. Nuclear magnetic resonance study of N-acetyl and N-nitroso derivatives has been used to clarify the environment of the secondary nitrogen atoms. Chemical and spectroscopic evidence leads to the formulation XVb for the related alkaloid ormojanine, C20H31N3.Both alkaloids were found to give 3-n-pentyl-6,8-dipropylquinoline together with the corresponding 3-n-butyl derivative in a catalytic dehydrogenation. The possible mechanism of formation of these dehydrogenation products is discussed and their synthesis is described.