3-Cyano-11-oxo-3,4-seco-12a-aza-C-homoolean-4(23)-en-28-oic acid methyl ester

Acta Crystallogr Sect E Struct Rep Online. 2012 Feb 1;68(Pt 2):o532. doi: 10.1107/S1600536812002863. Epub 2012 Jan 31.

Abstract

The title compound, C(31)H(48)N(2)O(3), is a Beckmann rearrangement product. The isopropenyl and meth-oxy-carbonyl groups have β-orientations, whereas the 2-cyano-ethyl group has an α-orientation. In the triterpenoid skeleton, the seven-membered lactam ring, as well as the three six-membered carbocyclic rings, have chair conformations. In the crystal, mol-ecules are linked via nonclassical C-H⋯O hydrogen bonds into layers parallel to the ab plane.