Transformations of the 2,7-Seco aspidosperma alkaloid leuconolam, structure revision of epi-Leuconolam, and partial syntheses of leuconoxine and leuconodines A and F

• Main Authors: Kam, T.S., Low, Y.Y., Hong, F.J., Lim, K.H., Thomas, N.F.
• Format: Article
• Language: English
• Published: American Chemical Society 2013
• Subjects: QD Chemistry
• Online Access: http://eprints.um.edu.my/10379/1/Transformations_of_the_2%2C7-Seco_Aspidosperma_Alkaloid_Leuconolam%2CStructure_Revision_of_epi-Leuconolam%2C_and_Partial_Syntheses_of_Leuconoxine_and_Leuconodines_A_and_F.pdf; http://eprints.um.edu.my/10379/

Several transformations of the seco Aspidosperma alkaloid leuconolam were carried out. The based-induced reaction resulted in cyclization to yield two epimers, the major product corresponding to the optical antipode of a (+)-meloscine derivative. The structures and relative configuration of the products were confirmed by X-ray diffraction analysis. Reaction of leuconolam and epileuconolam with various acids, molecular bromine, and hydrogen gave results that indicated that the structure of the alkaloid, previously assigned as epi-leuconolam,was incorrect. This was confirmed by an X-ray diffraction analysis, which revealed that epi-leuconolam is in fact 6,7-dehydroleuconoxine. Short partial syntheses of the diazaspiro indole alkaloid leuconoxine and the new leuconoxine-type alkaloids leuconodines A and F were carried out.