Propargylaminyl 3α-hy-droxy-11-oxo-18β-olean-12-en-29-oate

The title compound, C(33)H(49)NO(3), is the propargyl-amide of 18β-glycyrrhetinic acid, a penta-cyclic triterpenoid of inter-est as a therapeutic agent. The five six-membered rings of the glycyrrhetinic acid moiety show normal geometries, with four rings in chair conformations and the unsaturated ring C in a half-chair conformation. In the crystal, the terminal N-propargylcarboxamide group has remarkable structural effects on weak hydrogen-bond-like inter-actions. Particularly noteworthy are an inter-molecular O-H⋯π inter-action accepted side-on by the terminal alkyne group [O⋯C = 3.097 (2) and 3.356 (2) Å] and a short inter-molecular C-H⋯O inter-action [C⋯O = 3.115 (2) Å] donated by the alkyne C-H group. An N-H⋯O [N⋯O = 3.251 (2) Å] and a C(alkyl)-H⋯O [C⋯O = 3.254 (2) Å] interaction complement the crystal structure.