Tuberostemoamide hemihydrate

In the crystal structure of the title compound {systematic name: (1′S,2R,2′R,3′S,6′R)-3′-ethyl-4-methyl-5H-5′-oxa-10′-azaspiro[furan-2,4′-tricyclo[8.3.0.02,6]tridecane]-5,11′-dione hemihydrate}, C17H23NO4·0.5H2O, the asymmetric unit contains two molecules of tuberostemoamide with similar conformations and one water molecule. The tuberostemoamide molecule is composed of one seven-membered ring (A) and three five-membered rings (B, C and D). Ring A exists in a chair conformation, both rings B and C exist in envelope conformations, and ring D is almost planar with a mean deviation of 0.0143 (4) Å in one molecule and 0.0095 (3) Å in the other.. The dihedral angles between the planes of rings C and D are 75.1 (3)° in one molecule and 74.5 (3)° for the other. The solvent water molecule links the tuberostemoamide molecules through O—H...O(ketone) hydrogen bonds. Weak C—H...O interactions are also present, involving both the water molecule and a heterocyclic ether O-atom acceptor.