1. (a) Uemura, D.; Chou, T.; Haino, A.; Nagatsu, S.; Fukuzawa, S.; Zheng, S.; Chen, H. J. Am. Chem. Soc. 1995, 117, 1155. (b) Chou, T.; Kamo, O.; Uemura, D. Tetrahedron Lett. 1996, 37, 4023. (c) Chou, T.; Haino, T.; Kuramoto, M.; Uemura, D. Tetrahedron Lett. 1996, 37, 4027.
2. Conditions for the isolation of pinnamine (1): column, Develosil ODS HG-5 (4.6×250 mm); solvent, MeOH:H2O:TFA (20:80:0.1); flow rate, 1.0 mL/min; detection at 210 nm.
3. Djerassi, C.; Records, R.; Bunnenberg, E.; Mislow, K.; Miscowitz, A. J. Am. Chem. Soc. 1962, 84, 870.
4. (a) Snatzke, G. Tetrahedron 1965, 21, 413. (b) Snatzke, G. Tetrahedron 1965, 21, 421. (c) Snatzke, G. Tetrahedron 1965, 21, 439.
5. It has been known that the CD spectrum of the transoid enone, when distorted clockwisely, displayed a negative Cotton effect in the region of the n–π* transition and a positive Cotton effect in the region of the π–π* transition, and that the CD spectrum of one distorted anticlockwisely displayed the opposite sign to one distorted clockwisely.