Synthesis of the alkaloids, 5-hydroxy-6-methoxyonychine (5) (isoursuline) and 6-hydroxy-5-methoxyonychine (6) (ursuline), was accomplished by an application of a synthetic method for constructing cycloalkenopyridines from oxime O-crotyl ethers and the synthesis revealed that the structure of the azafluorenone from Oxandra xylopioides should be revised to 6-hydroxy-5-methoxyonychine from 5-hydroxy-6-methoxyonychine. Furthermore, the synthesis of kinaba-line (7) will be described. During the course of the synthesis of onychines, the chemical shift differences of the signals of C_7-H and C_1, C_7, and C_<7a> on ^1H-and ^<13>C-NMR were available to the stereostructure determination of E- and Z-isomers of oxime O-methyl and O-allyl ethers of indan-1-ones.
