title: 3-Cyano-11-oxo-3,4-seco-12a-aza-C-homoolean-4(23)-en-28-oic acid methyl ester.
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.
authors.forename: A
authors.initials: A
authors.lastname: Froelich
authors.forename: B
authors.initials: B
authors.lastname: Bednarczyk-Cwynar
authors.forename: A K
authors.initials: AK
authors.lastname: Gzella