Isocraugsodine, an n-arylidenephenethylamine from Crinum asiaticum and its e-z isomerism

Abstract

A new Schiff's base, named isocraugsodine, was isolated from the fruits of Crinum asiaticum. Its N-(3- methoxy-4-hydroxybenzylidene)- 4′-hydroxyphenethylamine structure was assigned on the basis of chemical trans- formation and comprehensive spectroscopic evidence. The temperature-gradient distribution of the three isomeric forms (1a⇌1b⇌1c) of the Schiff's base was determined by high resolution 1H NMR analysis. Isocraugsodine is considered as a direct precursor to Amaryllidaceae alkaloids. © 1988.