1. (a) Findlay, J. A.; Lin, J.-S.; Radics, L.; Rachit, S. Can. J. Chem. 1981, 59, 3018;
2. (b) Findlay, J. A.; Lin, J.-S.; Radics, L. ibid. 1983, 61, 323;
3. (c) Sehgel, S. N.; Czerkawski, H.; Kudelski, A.; Pander, K.; Saucier, R.; Vezina, C. J. Antibiot. 1983, 36, 355;
4. (d) Narita, T.; Matsumoto, M.; Mogi, K.; Kukita, K.; Kawahara, R.; Nakashima, T. ibid. 1989, 42, 347. For isolation of related substances, see: Yamashita, N.; Shin-ya, K.; Furihata, K.; Hayakawa, Y.; Seto, H. ibid. 1998, 51, 1105.
5. An NOE experiment gave a clue to the correct stereochemistry, where the NOE observed between C(3′) and C(5′) proton was conclusive. Also, personal communication from Dr. Y. Saito, Kyowa Hakko Co., is acknowledged.