Abstract
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.
