(+)-Methyl 3β-acet-oxy-13-carb-oxy-19-hy-droxy-11-oxo-C-norolean-18-en-30-oate γ-lactone

Acta Crystallogr Sect E Struct Rep Online. 2010 Sep 18;66(Pt 10):o2597-8. doi: 10.1107/S1600536810036901.

Abstract

The title compound, C(33)H(46)O(7), is an unusual oxydation product of the therapeutic agent glycyrrhetinic acid that has, in comparison to the latter, a distinctly altered triterpene structure with one five- and four six-membered carbocycles complemented by a γ-lactone ring with a spiro-junction and a ring double bond. The junction between the five-membered ring C, a cyclo-penta-none ring, and the six-membered ring D, previously in question, was found to be cis, confirming earlier structure assignments based solely on chemical transformations. In the solid state, the compound exhibits five intra- and four inter-molecular C-H⋯O inter-actions with H⋯O distances less than or equal to 2.70 Å and C-H⋯O greater than 100°.