Synthesis, Structural Determination of a New Ocotillol Derivative and its Epimer

Epimeric 20S, 24-epoxy-dammarane-3β, 6α, 12β, 25-tetraol acetic ester was synthesized from 20(S)- protopanaxatriol in the presence of acetic anhydride and the product oxidated by m-CPBA. 20S, 24R-epoxy dammarane- 3β, 6α, 12β, 25-tetraol (ocotillol derivative) and its epimer were synthesized by saponification in the presence of sodium hydroxide in 1:1 molar ratio. The structures of the two compounds were characterized by X-ray diffraction method. The results showed the configuration of C-24 of two epimers as S-form (4, ocotillol derivative) and R-form (3, epimer), respectively. Keywords: Ocotillol, derivative, epimer, synthesis, structure determination, ginsenoside, isoproterenol, ocotillol derivative, protopanaxadiol, saponin, protopanaxatriol, semi-solid, ORTEP representations