2 CYCLOHEXANESPIRO-5'-HYDANTOIN MONOHYDRATES

Cyclohexanespiro-5'-hydantoin monohydrate, C8H12N2O2 . H2O, has a chai r-shaped cyclohexane ring with endocyclic torsion-angle magnitudes in the range 54.4 (2)-56.3(2)degrees. All potential hydrogen-bond donors are involved in intermolecular hydrogen bonding, with lengths in the r ange 2.760(2)-2.908(2) Angstrom. In its indolyl adduct, 2-(3-indolyl)c yclohexanespiro-5'-hydantoin monohydrate, C16H17N3O2 . H2O, the cycloh exane moiety adopts a chair conformation with the indolyl substituent in an equatorial position. The N-H portion of the hydantoin ring is ci s to indolyl, while the C=O of the hydantoin is trans. Endocyclic tors ion-angle magnitudes of the cyclohexane ring are in the range 54.2(2)- 56.7(2)degrees. All potential hydrogen-bond donors are involved in int ermolecular hydrogen bonds, with lengths 2.828(2)-3.187(2) Angstrom.