2-(1-Amino-4-tert-butyl-cyclo-hex-yl)acetic acid (tBu-β(3,3)-Ac6c) hemihydrate.

The title compound, C12H23NO2·0.5H2O, crystallized with two 2-(1-amino-4-tert-butylcyclohexyl)acetic acid mol-ecules, which are present as zwitterions, and one water mol-ecule in the asymmetric unit. The mol-ecular structure of each zwitterion is stabilized by an intra-molecular six-membered (C 6 ) N-H⋯O hydrogen bond. In the crystal, the two independent zwitterions are linked head-to-head by N-H⋯O hydrogen bonds. Further O-H⋯O and N-H⋯O hydrogen bonds link the zwitterions and the water molecules, forming sandwich-like layers, with a hydrophilic filling and a hydrophobic exterior, lying parallel to the ab plane.