1. Reviews: (a) Ninomiya, I.; Naito, T. InThe Alkaloids; Brossi, A., Ed.; Academic Press: San Diego, 1983; Vol. 22, pp 189−279. (b) Ninomiya, I.; Yamamoto, O.; Kiguchi, T.; Naito, T.; Ishii, H.Heterocycles1977,6, 1730−1734. Ninomiya, I.Heterocycles1974,2, 105−123.