Lycopodium Triterpenoids. (7). The Structures and Partial Syntheses of 16-Oxoserratenediol, 16-Oxo-21-episerratenediol, 16-Oxodiepiserratenediol, 16-Oxoserratriol, 16-Oxo-21-episerratriol, and 16-Oxolycoclavanol, [alpha], [beta]-Unsaturated Ketones of Serratane Group

Five new triterpenoids occurring in various Lycopodium plants were shown to be 16-oxoserratenediol (1a), 16-oxo-21-episerratenediol (2a), 16-oxodiepiserratenediol (3a), 16-oxoserratriol (6a), and 16-oxolycoclavanol (7a) respectively, by spectral and chemical means, and the structures assigned were finally confirmed by partial syntheses from the corresponding deoxo-compounds. Potential utility of the solvent shift experiment in NMR and the resulting TH-effect for structural and stereochemical problems was indicated. A conjugated ketone isolated from L. cernuum by Inubushi, et al. was identical with the synthetic 16-oxo-21-episerratriol (19c).