The title compound, C22H22N2O5, contains two conformation-ally similar molecules (A and B) in its the asymmetric unit (r.m.s. overlay fit for the 29 non-H atoms = 0.194 Å). In each molecule, the lactone ring has an envelope conformation with the spiro C atom as the flap. In the crystal, A+A and B+B inversion dimers linked by pairs of N - H⋯O hydrgen bonds occur; in both cases, R22(8) loops are generated. A weak C - H⋯O interaction is also observed, which links the dimers into  chains.
|Number of pages||2|
|Journal||Acta Crystallographica Section E: Structure Reports Online|
|Early online date||9 Apr 2015|
|Publication status||Published - 1 May 2015|
- Crystal structure
- N - H⋯O hydrgen bonds