Triterpenoid glycols carrying hydroxy-groups at C3 and at one of 4, 4-dimethyl groups were converted to the corresponding acetonides (A-D), whose characterization by nuclear magnetic resonance spectroscopy were discussed in connection with their stereochemical properties, and a reliable method to determine their stereochemistry was presented. The stabilities of these acetonides to hydrolytic cleavage were also discussed. The conformation of the monoacetonide (16) derived from platicodigenin was suggested to be as 16b.
通过核磁共振光谱分析,讨论了三
萜类乙二醇的特征及其立体
化学性质,并提出了确定其立体
化学性质的可靠方法。此外,还讨论了这些
丙酮对
水解裂解的稳定性。结果表明,由 platicodigenin 衍生的单
丙酮(16)的构象为 16b。