1. [1a] Some of these data were presented at the 32th Symposium on the Chemistry of Natural Products, Symposium Papers, p. 304, Chiba, Japan, October 1990.
2. [1b] – Part IV: ref.[2c].
3. [2a] , , Liebigs Ann. Chem. 1986, 638–646.
4. [2b] – , , , , Liebigs Ann. Chem. 1990, 943–947.
5. [2c] – , , , Liebigs Ann. Chem. 1991, 1285–1289.